Curt Class III/IV Hitch Install on 140"

famof8

Famof8 + 1 = Famof9!
After combing the board, contemplating the ease of Seek's Hidden Hitch install, and debating on the design of the different add-on hitches, I settled on the Curt Class III Hitch for my 140" Passenger Sprinter. I like the fact the Curt design has am extra set of bolts at the front of the hitch to distribute the load better.

As others have stated, the Curt Class III is rated for 6,000 lbs trailer weight with 600 lbs of tongue weight or when equipped with a weight distribution hitch, 10,000 lbs trailer weight and 1000 lbs of tongue weight. Both are over the Sprinter's recommended max tow capacity. I have heard others recommend installing the Class IV since it is just a few bucks more. I figured the III is overkill, why do I need the IV.

When it arrived this afternoon I was glad that I ordered the Class III and not the IV as this baby is HUGE! I could not imagine the additional size of the tubing and braces for the IV. The Class III receiver tube juts out about 6.5" from the bumper. If you have the rear step bumper, no problem, it will cover it similarly to Seek's pictures of his Hidden Hitch. If you do not have the rear step bumper (I do not), then be prepared to bump/scrape your knees and shins.

Overall, the hitch was easy to install and includes all of the necessary parts required. I do recommend having an extra set of hands available, especially during templating and installation. The hitch does require drilling two new holes and enlarging two existing holes (two on the driver's side beam and identical on the passenger side beam.) Drilling the frame was easily accomplished with a 1-1/8" Uni-Bit (step bit). You must then fish (included) a carriage bolt and associated brace into the enlarged 1-1/8" holes, across the existing bolt paths in the frame and out the new 9/16" diameter holes. Patience is a virtue for this part! I used an extra piece of wire I had laying around to simplify the fish process. Once the wire is through, put the bolt and brace on the included fish and tape the free end to the piece of wire. Pull through while working the brace into the hole so it will lay in the proper position when installed (short end at rear of truck). I was able to complete this process in about 10 minutes. A word of caution... be certain that you go between the bolt paths and not below or above them. The carriage bolt will not fit through unless you are in the middle. I know from experience. It sucks to pull out and try again once the bolt and brace are in the 1-1/8" hole. With the carriage bolts in place, lift the hitch into position and place the included spacer plates between the hitch supports and the frame. The spacer will need to have a corner removed if you have the step bumper. The brace is prepared to make this alteration. I found it helpful to install one bolt in each side of the frame to support the hitch while I installed the nuts on the carriage bolts. Be sure not to push these bolts back into the frame during this period. Finish installing the remaining bolts, washers, and nuts. Tighten each to the described torque and relish in the delight of a job well done!

I will be posting pictures of this process within the next few days.
 
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famof8

Famof8 + 1 = Famof9!
OK, as promised... pictures. This two day project (kids and activites excluded would equal one long day) was probably the filthiest experience I have had in quite some time. I do not think the original owners ever took the van to wash the undercarriage... ever. :eek: That is in my plans for the immediate future. Until then, please kindly disregard the nasty road filth in every picture. :smilewink:
 

famof8

Famof8 + 1 = Famof9!
To begin, make sure you have everything needed for your install. For my purposes I needed a hitch, powered taillight converter able to support 6-7 Amps per channel, and a brake controller. (My van does not have the tow prep package.)

Here is my list of materials used:

Hitch - Curt Manufacturing Class III Custom for Sprinter #13250 (comes complete with bolts, nuts, washers, spacers, and small bolt fish); Taillight Converter - Hopkins Towing Short Proof Power Converter #46365; 7 & 4 Way Plug - Hopkins Towing Multi-Tow 7 to 4 Adapter #47185; 40 Amp Circuit Breaker – Balkamp #782-3116; 30 Amp Circuit Breaker - Balkamp #782-3105; 10AWG 2 Conductor Stranded Jacketed Cable; 16AWG Stranded Cable; 2' of 1/2" Wire Loom; Pkg of 1/4" Yellow Crimp Ring Terminals; 4" and 7" wire ties Black UV Rated; 3M Super 33 Electrical Tape; El-Cheapo Type Electrical Tape for fishing wires; Small Tube of Black RTV; Butane Canister for Solder Iron; Thin electronics; Small packet of Dielectric Grease.

Here is a list of tools I needed:

1/2" Drill, 1 1/8" Unibit, Butane Solder Iron, Large Ratchet, Metric Short and Long Sockets, Large Crescent Wrenches, 19mm Combination Wrenches, Torque Wrench, Small 1/4" Ratchet, small 10mm 1/4" socket, long 11mm 1/4" socket, wire cutters, wire strippers, wire fish (wire clothes hanger works wonders), multi-meter (can use test probe if desired), hammer (not really needed, it just wouldn't be a good job without one), crimp tool, assortment of self tapping screws (may be needed), double sided tape (may be needed), shop towels, small flashlight, and maybe a few others that I used for one reason or another, but just cannot remember.

PS. My son needed his sippie cup. He refused to participate without it. :lol:
 

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famof8

Famof8 + 1 = Famof9!
Step one, hold hitch up to frame. I found it easier to have a person on each side hold the hitch and place a bolt on each side to support the hitch while marking the holes that need to be drilled (green sharpie oval in the third picture). Once marked, remove the bolts and set the hitch to the side for now. Take the drill and unibit and enlarge the hole on the bottom of each frame to 1 1/8" in diameter (these holes are located directly under the four bolt paths as shown in pictures 1 and 2). Now use the unibit and drill the marked holes to 9/16". The enlarged hole will be there to fish the carriage bolts into the frame. The marked/drilled holes will hold the carriage bolts. Now, take the included bolt fish and attach it to the end of one carriage bolt. Slide the long metal plate with a square hole onto the wire bolt fish as well. This will take some thinking as the short end of the plate will need to face the rear of the van. I used a piece of wire to fish between the holes. As stated in the first post, be sure to fish the wire in the middle of the existing bolt paths or the carriage bolt will not fit through. Once fished, attach the wire bolt fish onto the wire and pull through, being careful to orienient the plate so the long end will face the front of the truck when in it's proper place. (The carriage bolt head should be the last piece that enters the enlarged hole.) Pull the wire bolt fish through the hole and then through the plate. You should now have the end of the carriage bolt through sticking out of the drilled hole. Twist the bolt to ensure there is minimal turning inside the frame and that the carriage bolt is properly inserted in the flat plate. If not... start over until correct. Repeat this procedure for the other side. Once both carriage bolts are in place, lift the hitch back into place, careful not to push the carriage bolts into the frame. Insert at least one bolt on each side to support the hitch. I then put the nuts on the carriage bolts to avoid catastophe (having to re-fish the bolts). With the carriage bolts secure, pull out the inserted bolt on one side of the hitch and place the included metal spacer in between the hitch and the frame. The corner of the plate that can be broken off goes to the biggest hole on the hitch. If you have the step-bumper, then break the tabs off. Insert the bolts on the side with the spacer and repeat on the other. Once all bolts are inserted (three on each side, one carriage bolt on each side, and if you have the step bumper, then one existing bolt on each side) tighten all bolts down to proper torque specification as listed on the instruction sheet (75lb-ft) except the bumper bolts (if present) which tighten to their original torque (73lb-ft). (Picture 4)

These detailed instructions are simplified by a picture and seven installation steps on the instruction sheet.
 

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famof8

Famof8 + 1 = Famof9!
I admit I was a little short sided with the thread title as I neglected to mention the wiring for lights and brake controller. However, I have those pictures and steps as well. So, without further ado, here you go.

I chose the Hopkins Short Proof Taillight Converter as it protects the vehicle and the trailer from shorts between the two, is powered from the vehicle battery, and has the amperage push that I need for my trailer's lights. The kit comes with everything that is needed to complete the install... in theory. I found that the wire to the right turn signal was not long enough so I had to supplement with another wire. I also chose to solder my connections instead of using the scotchlocks (or happy clips) for tapping into the wires to the lights. Installation was otherwise painless.

The kit is composed of the converter with a four-pin plug wired to it along with the necessary power, ground, stop, left turn, right turn, and tail light pigtails. It also includes a fuse holder and fuse for direct connection to the battery.

To start, I removed the negative and positive battery posts. I then removed the inside rear pillar trim panels and light boards. During installation I found it necessary to remove the left lense assembly, so you might as well remove it at this point as well. (It is not necessary to remove the side trim panels as shown in the photos.) Under the van just to the front of the rear cross beam you will find a rubber plug with wire loom running to it. Pop the plugs out of their holes. They will not fully come loose as the wire loom holds them in place.
 

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famof8

Famof8 + 1 = Famof9!
At this point grab your favorite metal wire coat hanger and fish between the left lense housing and the rubber plug that was removed under the van. I found it easier to fish from underneath since I was shooting for a bigger hole... much easier. Have someone grab the fish inside the lense housing and pull it out of the pillar enough to attach the four-pin plug from the converter. Attach the four-pin plug, the wire you will be using for the green right turn signal wire (remember the one in this kit was not long enough), and the red battery wire to the fish with some super economy electrical tape. Make it easy on yourself and also attach a wire to the fish for the reverse lamps if you will be connecting a seven-pin conector. This is not included in the kit and will need to be supplied separately. Pull all the wires carefully through the lense housing and out of the lower rubber plug hole. Continue to pull all the wire through for the battery, the right turn, and if needed the reverse wires. You will only need about 12" of the four-pin connector outside the rubber plug. Tuck the remaining length in the plug hole. Route the right turn signal wire around the back of the van. I followed the existing wire harness that was existing from the left to the right lense housings. The battery wire will be pulled up front shortly. Be sure to coil and set out of the way so that it isn't damaged. At this point, you will either use the scotchlock connectors included in the kit or solder iron to connect the converter pigtails to the wire harness on each side. (The wiring colors will vary with the converter selected.) The following connections are made on the driver's side light pigtail ( connects to the light board assembly.) I found it easier to disconnect this pigtail from the board since I was soldering the connections. To remove, insert a flat blade screw driver into the harness lock. Gently work the harness side to side while pulling out until the plug comes out of the board. I did not cut any of the wires in the harness to preserve their connections. I used a razor blade to remove the insulation around the wire where the converter pigtails were connecting. The red wire marked brake will connect to the black wire with brown stripe on the driver's side pigtail. The yellow wire marked left turn will connect to the black wire with white stripe. The brown wire marked tail will connect to the gray wire with black stripe. The green wire marked right turn will be the only wire left to connect to a harness. This wire will be connected to the wire that was ran to the right side pillar lense housing. All connections are now made, unless you will be connecting a reverse lamp wire. If so, connect the wire from used for the reverse lamp to the white wire with red stripe on the driver's side harness. All connections are now made on the left side. Tape all connections up with 3M Super 33 electrical tape (or equivalent). I really dislike using double sided tape for mounting things, but for this project, I did not have much choice. Place three pieces of double sided tape on the rear of the converter. Stick the converter to the sheet metal inside the lamp housing. Be sure to leave enough room to re-install the lamp housing assembly. Once mounted, re-install the wiring harness to the light board. Install the lamp housing back into the pillar. I connected the white wire marked ground to one of the studs that holds the assembly to the rear pillar. Re-install the light board and the pillar trim.

On the right side pillar we need to repeat the fish up from underneath the van. The wire ran to right side from the converter will need to be fished up through the passenger side rubber plug hole and into the lamp housing area. Once the wire is in place connect it to the black wire with green stripe on the light board's wiring harness. Tape all connections and re-assemble this side. Underneath will need to be buttoned up as well. Take a pair of cutters and make a small slice in the side of each rubber plug. Route the wires that were fished through the plug hole into this slit. Re-install the plug. Now seal the slits with a good helping of RTV.
 

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famof8

Famof8 + 1 = Famof9!
A picture of the finished rubber plug that has been sealed. This is the driver's side. I decided to use wire loom to conceal the wires and add some extra protection.
 

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famof8

Famof8 + 1 = Famof9!
I have not discussed the battery wire from the converter yet as I included it with my run to the front with the seven-pin plug. To avoid going out of sequence, I will discuss that run now. The battery wire (and the 10 gauge 2 conductor wire for the seven-pin plug) should be routed along side the existing wiring harness going from the driver's side rear all the way to the engine. This will be challenging as it is routed above the fuel tank. There are two choices, route around the tank, or fish the wire along the existing harness between the tank and the floor. It takes some extra time, but I ran above the tank and along with the other harness. With the wire run up to the engine compartment, route it to the battery. Make sure it is not in the way of the steering gears and not rubbing against the a rough spot on the frame. If you are like me, your battery wire from the converter is getting very short. I had just enough to properly route and connect the wire. Wire tie everything up and if desired, wrap with wire loom. At the battery, take the fuse holder included with the kit and connect it to the positive battery post where the auxiliary attachments come off the main post. Connect the other end of the fuse holder to the converter's battery wire that has been routed to the front. This completed the converter install. Test and enjoy! :clapping:

For those like me, unfortunately your job is not done. The seven-pin plug must be installed and wired. Good news though. Most of the work is done! Back at the rear of the van the seven-pin plug must be mounted. I selected the driver's side of the hitch. The seven-pin plug used also has a four-pin plug to avoid the use of adapters. I really liked that feature as my old vehicle required a seven-pin to four-pin adapter that always seemed to disappear when it was needed. Wirirng was a snap. The reverse wire that has already been pulled down from the left lamp board will be wired to the purple wire on the seven-pin plug. The four-pin plug coming from the converter will plug into the seven-pin's four-pin harness. Be sure to insert the dielectric grease since this is a somewhat permanent connection (at least for me.) I used a wire tie around the four-pin plugs to make sure they stay togther. The remaining wires have already been run to the front with the converter wire. Take the 10 gauge wire ran tot he front and connect one conductor to the black lead on the seven-pin plug. This will serve as the lead for the battery. The remaining conductor will be connected to the blue wire on the plug. This is the brake wire. Button up all connections and wrap in 3M Super 33 or equivilant.
 

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famof8

Famof8 + 1 = Famof9!
We are almost done! Back at the front we need to finalize connections. First, let's install the required circuit breakers. I mounted mine just above the battery on the engine compartment wall. I used a 40 Amp breaker for the seven-pin battery wire and a 30 Amp breaker for the brake controller. Take the 10 gauge wire and connect the conductor used for the battery connection at the plug and connect it to the Aux side of the 40 Amp breaker with a ring terminal. The remaining conductor needs to be set aside for connection to the brake controller. Take the remaining 10 gauge wire and cut enough to run from each circuit breaker to the battery. Place ring terminals on each end and connect between the Battery terminal on each circuit breaker to the auxillary lug on the positive battery post. The remaining 10 gauge cable will be used to run between the brake controller and the circuit breaker. There are two rubber plugs on the firewall just to the side of the master cylinder. I ran my 10 gauge wire through the upper plug. I first drilled a small hole for the wire to be ran through. I wanted to keep my brake conductor constant through the wiring, so I used the same conductor color thatt I connected to my seven-pin harness blue wire to the 10 gauge conductor we set aside a few minutes ago. Connect (I soldered mine) and tape with 3M Super 33 electrical tape or equivalent. The remaining conductor will go the Aux terminal on the 30 Amp circuit breaker. I also ran a wire through the rubber grommet into the passenger compartment to use as a ground for my brake controller. I connected the engine side to the ground lug on the fire wall. Button up all connections and let's move into the driver's side floor. I mounted my brake controller under the driver's dash cubby. I connected the conductor from the Aux terminal on the 30 Amp breaker to the black wire on the controller pigtail marked battery. I connected the other conductor (trailer brakes) to the blue wire marked trailer brakes. That leaves two more wires on the pigtail The white wire is ground and is connected to ground wire that I ran through the rubber grommet. The remaining wire on the pigtail is red. This is the brake signal wire. I had to remove my brake switch on the brake pedal to test for the cold connection (the one that is only live during brake application.) For me, that was the black wire with the red stripe. I tested by connecting my multi-meter ground lead to a brake pedal mounting lug. I then probed the four brake switch connections for 12V +. Remember, if you have the switch removed from the brake pedal assembly, out is brake on. In is brakes off. Splice the red wire from the controller onto the cold connection and re-install brake switch. Be sure to test for proper operation before driving!!!! :professor: All connections are complete. Seal the rubber grommet penetration with RTV and clean up. Reconnect your positive and negative battery cables. Start the van and make sure all of the ligts are working. If good, then connect to your trailer and test. All should be operational. Great job! :rad:
 

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famof8

Famof8 + 1 = Famof9!
I hope that others have as much fun and enjoyment that I have experienced with this project. I was even able to enlist the assistance of most of my family and neighbors! My wife made the perfect slits and performed the patch on the rubber plugs. My oldest son helped fish wires and wire-tie under the van. My neighbors assisted with hitch installation and one even came back to try his hand at soldering and wire installation. My youngest son threw parts and tools into the yard and street, which then required the help of my middle two in order to retrieve them all. For those with kids, you may have noticed the infant swing leg in the very first picture... yes even she was there to help. The best part for us was connecting the camper and seeing everything come to life, knowing that once again I (Dear Husband and Daddy) have not permanetly killed our Sprinter and have saved the family a bushel of money at the same time! :cheers:
 
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maxextz

Rollin Rollin Rollin.....
well done thats a great writeup and brilliant pics:thumbup: for someone wanting to do the same this will be a great help.:popcorn:
max......:smilewink:
 

Sacto John

New member
I wired up my 118" this weekend using your pictures and instructions as a guide. Your post helped immeasurably and the install went flawlessly.
 

famof8

Famof8 + 1 = Famof9!
Glad to hear Sacto John. Did you go with the powered or unpowered converter?
 

Sacto John

New member
I used a powered converter. The hardest part was running the wire up to the battery, but is more of an inconvenience than a hardship. Going to pull the boat this coming weekend, and I will try to take some pictures then.
 

jacobkoski

New member
I am going to be installing a hitch and trailer wiring following this threads instructions on my 2006 158" Passenger Sprinter. This is my first post ever and I have owned the Van for 3 days! It has 113,000 miles and is going to be a work/fun vehicle. I have a whole list of things to do on it and this is #1

I wanted to share my shopping list to ask for any suggestions/changes prior to ordering.

Hitch Class IV Square Tube Hitch - Exposed http://www.autoanything.com/towing/73A3874A0A0A3033565.aspx
powered Converter http://www.amazon.com/gp/product/B0002Q804K/ref=ox_sc_act_title_1?ie=UTF8&m=ATVPDKIKX0DER
Adapter 7 pin http://www.amazon.com/gp/product/B0002Q80GS/ref=ox_sc_act_title_2?ie=UTF8&m=ATVPDKIKX0DER
Controler http://www.amazon.com/Tekonsha-9030...KMLC/ref=sr_1_8?ie=UTF8&qid=1322092982&sr=8-8

30 and 40 amp circuit breaker I have no source for these
10AWG 2 Conductor Stranded Jacketed Cable I have no source
16AWG Stranded Cable no source
2' of 1/2" Wire Loom no source
Pkg of 1/4" Yellow Crimp Ring Terminals no source
Small packet of Dielectric Grease. no source

I have a Napa and a Car Toys close by I am assuming the have they circuit breakers wire etc.?
Just thought the shopping list could be updated with better/cheaper vendors.
There is a powered converter kit for sprinters that is twice the price, is it worth it? longer wires? is there a kit that includes the wires neccesary for a 7 pin setup? any all in one solutions?
Also i had that brake controller in a ford truck previously and found the macro/micro adjustments difficult to dial in depending on the load fluctuations - any easy options more user friendly?


Thanks
Jacob Koski
Colorado
 

Aqua Puttana

Poly - Thread Finder
Ok I'm on my own! Will submit lessons learned

Sent from my DROIDX using Tapatalk
Your questions were pretty specific. I know I wasn't familiar with the part numbers you listed and I wasn't inclined to research them. I'm certain that put others off too.

...
30 and 40 amp circuit breaker I have no source for these
Fuses protect electronics better than circuit breakers. Circuit breakers have longer delays. I'd go with 30 amp max. CB's and fuses are available at auto parts stores.


10AWG 2 Conductor Stranded Jacketed Cable I have no source
West Marine


16AWG Stranded Cable no source
West Marine


2' of 1/2" Wire Loom no source
West Marine or use heater hose.


Pkg of 1/4" Yellow Crimp Ring Terminals no source
Any auto parts store.



Small packet of Dielectric Grease. no source
...
Thanks
Jacob Koski
Colorado
Vaseline works just fine for automotive. Good luck. vic
 

olivefoto

Windowless RV
Or you could buy a $159 .00 hitch , the ones made for the Toyota 4 runner are an exact match to the sprinter frame. :clapping:
 

MillionMileSprinter

Formerly Type2Teach
Bump. Just wanted to bump this wonderful write up on installing a hitch and trailer wiring for the T1Ns.
Summer and trailer pulling time has arrived!
 

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