Turn signal intermittent Repaired

Last Friday I connected my boat trailer to travel to a regatta. We drove about 2 1/2 miles and I noticed the turn signals seemed to not be working.
Added:

mrawsonw said:

... I'm pretty sure that if your hazards are working, the problem is with the "multifunction switch" (turn signal stalk. If your hazards don't work, it's more likely to be the turn signal relay or fuse panel.

Sent from my PH-1 using Tapatalk

Click to expand...

Good point.

The turn signals and emergency flashers do share the same flasher circuit.

vic

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Skip down to Post #15 for the FB #1 soldered jumper final successful repair.
Post #15.
https://sprinter-source.com/forums/showthread.php?p=374375#post374375

Dickknapp found a similar repair worked for an intermittent (unintentional... not designed) wiper problem.
https://sprinter-source.com/forums/showthread.php?p=536361#post536361

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When I stopped to check I found that if I put the turn signal lever to right or left it would give one or two funny clicks and then nothing. The first thing I figured was that the powered trailer light module had failed or somehow screwed things up.

I disconnected the trailer connector at the tongue. The turn signal response didn't change.

I went to the front and pulled the trailer module dedicated power fuse. The turn signal response didn't change.

At that point I also tried the emergency flashers which responded in a similar manner to the turn signals. One or two clicks, then nothin'.

Hoping that it might be a flasher or something simple I began operating the turn signal hoping to find the flasher location during it's one or two clicks operation. As I reached around under the dash to feel for things the turn signal started working correctly. By pulling/pushing a bit on the vent duct I could get the failure mode back.

To keep this long story from getting unbearable, I was able to gently pull the harnesses around until the signals and emergency flashers started working properly.

We connected the trailer and drove the 350+ miles to Lake George, NY and back without any problems. I didn't even bother to check things when we arrived at our destination. I figured it was the perfect time to apply my patented, "If it's not f**kin' with you, don't f**k with it." operating mode. I just knew if I messed with it the chances were I'd end up with more trouble.

I've been so busy I haven't had a chance to check what the real problem is. I suspect it will come down to a chafed harness, but it could also be a loose connector. I know I'm now pushing my luck, but there's no slow time in sight for the next two weeks.

My searches didn't find similar turn signal symptoms and solution. Anybody here have any similar experience with their turn signal/emergency flashers and trace down the problem? Thanks, AP/vic

P.S. - I'm not working on it now because storm fronts have been rolling through all day. I might melt should I get wet.

Re: Turn signal intermittant wire harness

Strange symptoms.
Doing the same thing on both sides is really weird!
An open circuit usually results in a fast flash so I suspect you had a short somewhere but that would typically be only one side acting strange.
At least we can be confident that we will see an excellent write-up of what you find.

Re: Turn signal intermittant wire harness

Hey Vic : remember this https://sprinter-source.com/forums/showpost.php?p=56610&postcount=18

ah nevermind just it makes ya feel warm on stormy nights

Carl

Re: Turn signal intermittant wire harness

sprintguy said:

Hey Vic : remember this https://sprinter-source.com/forums/showpost.php?p=56610&postcount=18

ah nevermind just it makes ya feel warm on stormy nights

Carl

Click to expand...

Carl,
Not only did I contribute to that thread, I even thanked you for that one back then.

I've admitted to being a parrot here on the forum, but I've never claimed to have a memory like an elephant. And yes, doesn't help either.

Do you mind giving a guess as to the time it will take a DIY repair? (I know, that's probably in the post too.)

Thanks very much for the reminder. AP/vic

Re: Turn signal intermittant wire harness

I don't even remember seeing that one. Thanks for rehasing it, Carl.

Some pictures here on the innards...

https://sprinter-source.com/forums/showthread.php?t=4245

Re: Turn signal intermittant wire harness

Some follow-up.

I should be embarrassed to admit this, but we're almost family here so most of you know I'm that brother who will put things off, so here goes. I haven't done anything with my turn signal problem since late September when it gave it me trouble. I looked into removing the fuse block and checking the relay socket, but that looks like a pretty a big project... after all the signals have been working. I'm living on the edge all because I'm lazy.

There's some people who had better solutions than my method of just ignoring the problem hoping it won't return. Here's that thread.
https://sprinter-source.com/forums/showthread.php?t=9313

Hope this does some good. AP/vic

Re: Turn signal intermittant wire harness

I had the same blinker trouble on my 2004. The cause was the electronic module for the trailer lights. It was located at the end of the trailer wiring harness. Once I disconected it the blinker funtions went back to normal. I replace the module (you ca by the harnes with module in Walmarkt and all is fine. Maybe that will help you.

Sven

Re: Turn signal intermittant wire harness

Vic,

I had the same problem a couple of months ago - it initially appeared that it might have been the broken solder connection that Carl described, as I could touch the relay at the bottom of fuse block under the steering column and the turn signals would work normally .... sometimes ....

This problem started out where the turn signals would activate erratically and flash a number of times before just stopping - it become progressively worse over a short time, to the point where they eventually flashed only once before stopping ... and then not at all, if memory serves.

I replaced the relay at the bottom of fuse block under the steering column and have had no further problems since. (I don't have a trailer or any wiring for one however)

Re: Turn signal intermittent wire harness

After my mini-rant about people not following up on successful repairs, I figured I should dig up this post and supply what I found.

So it is not necessary for anyone to go back and read this thread, my turn signal/emergency flasher system was intermittent. I found if I reached under the dash and wiggled what I thought was a wire harness the signals would work for a time. It turned out that "harness" is a cable that goes from the ignition switch to the shifter. I believe that when I was moving that cable around it was pushing against the fuse block and shifting it slightly which caused a poor connection to make for a time.

The repair was to remove the fuse block under the steering column and tighten all the fuse and turn signal plug-in contact assemblies. The fuse block removal was very straight-forward. If my memory serves correctly I only needed a 10 mm socket and common tools.

A couple cautions if you do remove your fuse block.

* Disconnect the battery cable! I didn't and managed to blow my 100 amp fuse on the battery post. I know better.

* The fuse block needs to come down and out when removing it because it plugs into the turn signal assembly.

* Record what is where and remove all the fuses and relays before trying to get the covers off.

* Do not over-tighted the top 10 mm head fastener when you re-install the fuse block. The nut is only held in place by a plastic holder. Either someone over-tightened mine, or it seized over time. I tried everything I could to remove it, but the nut kept spinning. I finally needed to break the plastic out to remove it and then deal with the repair.
****
Here is a procedure to remove the bolt/nut. Thanks goes to Oly.
https://sprinter-source.com/forums/showthread.php?p=239067#post239067
****
MercedesGenIn shows a nice cable tie fix here.

MercedesGenIn said:

Hi there,

You may find this of some use for reference and a few tips:
http://www.mercedes.gen.in/WP35/unsual-intermittent-power-problems-mercedes-sprinter/

All the best
Steve

Click to expand...

****

Once the fuse block is out and the plastic covers are off it is a very simple matter to tighten the connection clips. I just used a pair of needle-nose pliers to crush them back together and close the distance. I did all the clips while it was out.

Going by where the ignition cable was pushing against the fuse block fairly high up, I believe my problem was in the connections up into the turn signal assembly and not a fuse. That is a guess.

After I put everything back together it worked fine. Then a bit later it started being intermittent again. I pushed home the three relays on the bottom and everything has been fine since.

These threads over in Stoopid Things have a bit more information about the fuses and fuse blocks in case you haven't stumbled upon it.

Some General Info about T1N Fuse Blocks, Fuses and Relays

https://sprinter-source.com/forums/showpost.php?p=87705&postcount=69

Some Cautions Regarding The Fuse and Relay Blocks
https://sprinter-source.com/forums/showpost.php?p=87709&postcount=70

The High Amp Compact Fuses off the Battery are not easy to find.

https://sprinter-source.com/forums/showpost.php?p=101112&postcount=82

Easy Steering Column Fuse Cover Removal and Fuse Bonus Packs

https://sprinter-source.com/forums/showpost.php?p=101589&postcount=84

More Fuse Information
https://sprinter-source.com/forums/showpost.php?p=106479&postcount=85

vic

Re: Turn signal intermittant wire harness

I just had the same problem with my signals and just jiggling the turn signal relay did the trick.
Hope it is a permanent fix...

Re: Turn signal intermittant wire harness

chris118 said:

...
Hope it is a permanent fix...

Click to expand...

It very well may be. Per Sprintguy Carl finding a loose flasher relay is not uncommon. I had tried that and it didn't help which is another reason I think it may have been one (some?) of the plug-ins to the turn signal assembly connect.

I apologize for spelling "intermittent" incorrectly in the title. That means the only ones who will find this on a search are the one that can't spell like I can't.
(Spelling has since been corrected. At least in the title.)

vic

Re: Turn signal intermittant wire harness

Thanks for the info on this problem. When I tried out my Sprinter it did not blink once and then started back working OK. The check engine light went off after fueling it at the same time so I thought problem solve and bought it. It stopped the other day and I spent some time checking fuses today found a blown one, but still no blinkers. Did a search found this, went and found the relay was loose. Turn signals are working fine thanks folks!

Re: Turn signal intermittant wire harness

I found my relay not so much loose, but not making a good connection due to age and oxidation. When my blinkers stopped blinking I removed the panel under the dash and wiggled the relays at the bottom of the fuse block.

The 1st. time I did it I just moved it a little bit, afraid to be to aggressive. The last time I did it I wiggled the **** out of and it hasn't been a problem since....who knows, one day I may remove it and clean the connection properly.

Dan

Re: Turn signal intermittant wire harness

My last repair for turn signal/emergency flasher intermittent operation was October 2010. So a bit over 3 years. The symptoms returned a bit ago. Prior to each failure almost each time I would notice a kinda stumble double-click of the turnsignal audible sound. When the flasher stopped, just wiggling the relay would restore operation. Rather than leaving the FB #1 cover off, my redneck response (thanks skydiver007) was to provide a finger hole for access.



The post is here.
https://sprinter-source.com/forums/showthread.php?p=220978#post220978

That worked just fine for quite some time, but lately the relay had needed more wiggling. I've read about poor solder connections being found in the FB #1 board so I figured that might be the problem.

The other day I removed my FB #1. The top captive nut which I epoxied in seems to be holding, but I didn't stress it by using the top bolt shoulder to wedge the FB #1 out from position. the method which I used was to loosen the bolt, move the FB #1 frame out a bit, loosen the bolt... repeat until free. That kept stress of the shoulder push off my repair. I used a similar procedure by pushing the FB #1 home as I snugged the bolt in. I don't know how strong my glued in nut is.

As an aside, my Goop glue with mesh tire patch on the sides held just fine. The mesh was easy to slice down with a blade for release.

I disassembled the FB #1 and closely inspected the solder connections. All looked pristine. I then popped the cover off the turnsignal relay for inspection. All looked great inside. While the relays were open I cleaned the contacts for insurance.

Close inspection of the realy blades showed some dark spots on the blades. I scraped/cleaned the blades on all my relays/fuses and used my fine contact burnish tool to clean all the socket insert clips. I also burnished all the fuse clips.

This is a similar contact set. I find them handy.



http://www.specialized.net/Speciali...ical-Contact-Burnisher-Set-35-3Piece-533.aspx

After cleaning everything I checked the fuse and relay contact gap. I found that a spark plug gap tool 18 thousandths wire made a good test for the fuse clips. Most all of the clips allowed the wire to pass with just a bit of resistance. I used a small duck bill pliers to adjust the few which seemed looser than the others. The relay clip gaps were a bit larger.I used the 25 (or maybe the 28?) as a won't go test because the wire size didn't fit as well as the 18 did on the relay clips. I only needed to adjust a couple.



The FB #1 is re-installed and everything is working fine again. If you experience the intermittent flash relay issue it may pay to just remove the turn signal relay, clean the blades, and burnish the socket clps with the FB #1 in place. It may save R&R of the assembly.

The procedure above was worthwhile for me DIY. I will say that the approx $100 replacement part, which comes complete with new electronics (the FB #1 has circuitry included on the board) with a full complement of new fuses and relays is not a bad option at all.

Some general Fuse Block information is here. (In addition to the threads already highlighted previously in this thread.)

Fuse Block #2 Fuse Map 2004
https://sprinter-source.com/forums/showthread.php?p=278122

vic

Re: Turn signal intermittant wire harness

The relay access finger wiggle hole has worked to get me by. Lately the turn signals have been more temperamental which has taken more frequent wiggles. I again removed the FB#1 to try to track down the problem.

I finally isolated my actual problem with my FB #1 Fuse Box #1 intermittent turn signal.

Dickknapp found a similar repair worked for an intermittent (unintentional... not designed) wiper problem.
https://sprinter-source.com/forums/showthread.php?p=536361#post536361

All the connections and solder points on the circuit board looked great visually. I noticed that there were some connection points joining the brass bars. I figured that maybe there was a "bar joint" which was bad. As I moved the assembly sections apart to see better I noticed that one of the turn signal relay pins came right loose from the circuit board. An inspection of the opposite side solder point still looked good even though the brass pin had pulled clear.

Anyway, the brass pin had burned a bit so just a simple re-solder wouldn't work. Access to the pin was very poor. I traced the relay socket/brass bar back a bit and found a clear spot to solder my blue jumper wire to. That allowed an easier solder point while still giving a route over to the bad solder pin connection.

If the failure mode on my board is typical, that may explain why the "Wiggle Fix" is generally successful. If you find a similar failure I recommend a jumper of some sort. The OEM circuit board solder point is pretty small. Once the connection is compromised just re-solder may not work. It appears that there's not much of anything other than that small brass connection point to handle any stress put on the relay pin/circuit board connection.

Added:
An Alternative to the long Jumper Wire Repair

If the small tip is burned it may be possible to bend/offset the pin a bit and use a small solid wire as a direct jumper. The solid wire would be slipped up through the circuit board hole and soldered where it parallels the pin. The wire would then be soldered to the board and chopped off close. One watch out would be whether there is enough room to slightly offset the pin. (I believe that there is.)

Some pictures.





The board connection. Before FB#1 assembly, I added some Goop glue to the blue wire/circuit board area to help with any possible vibration stress.



Steve Ball has some great information here.

MercedesGenIn said:

The fuse board can be stripped and looked over if needed. Have a look here if it any help.

http://www.mercedes.gen.in/WP35/unsual-intermittent-power-problems-mercedes-sprinter/

All the best
Steve

Click to expand...

vic

20170307, 20190307 - Repair holding fine.

Re: Turn signal intermittant wire harness

I have been having turn signal problems in my 2005 bare bones. Today I took out the fuse block and it all looks terrific, no corrosion etcetera. Looks so good, I think maybe my mechanic had changed it out. Anyway, I'm staring at it, disappointed to not find a fix to my turn signal problem, and then I realize that I'm looking right at the problem. Vic, the same place yours had a problem, mine also, but more subtle in appearance. The brass tip not sticking up through the blob of solder and little hole where it would have been. That told me the connection was poor there and ohm meter confirmed it. Am heating the soldering iron right now. In my case, I think I can just remelt it and be okay.
Thanks for all the useful posts here.

After I removed the solder, I was able to push the brass part up through the hole better and make a proper solder connection. Not tested yet but ready to go back in the vehicle.

From a recent thread. Corrosion was found on the FB #1.

travelbuds@verizon.net said:

Just replace the whole fuse box, it cost about $100 from Europarts of AD. I took mine apart a couple times to chase down a no start problem and ended up just buying a replacement.

Click to expand...

Aqua Puttana said:

I repaired my FB #1 mostly because I'm hard headed and didn't want to give up.

For the price it really makes more sense to just replace the entire FB #1. The FB #1 is a true module with on board electronics. The new part comes complete with all fuses and relays.

Replacing the FB #1 eliminates a bunch of guessing. If it doesn't cure the issues then at least it will not be a focus when you are paying for more troubleshooting. The price of the part is likely less than you will will pay a dealership to pull your Sprinter into the service bay and connect a scan tool.

The above said, my 2004 has been working flawlessly since I made my blue wire jumper repair. (Knocking/touching wood furiously as I typed that. )

vic

Click to expand...

So I have about the same problem on my 03. Turn signals quit working, pulled relay out and put it back in, started working till the next day same issue. Tried aftermarket relay, same issue. The 4 way flashers work, but the relay just buzzes when the turn signals are on. I took apart the fuse box, cleaned all the corrosion, no difference. Both left and right just buzz, while the 4 way works fine. So replace the #1 fuse box? Or could it be another issue?

The 2003 turn signals have their own sub-chapter (8W-52) in the service manual's wiring diagrams.
The Hazard switch operates a relay on Fuse Block #1 (under the steering wheel) and make use of fuses #6 and 9 on that panel.

But the left and right turn signal relays are spread around under the driver's seat, and use Fuse #8 on panel #1 to power the bulbs.
They also use a fuse on the driver's seat-side panel. It's listed as #5 in the diagrams, but (as usual) your position may differ.
(on my fuse list, they don't cite a "turn signals" fuse over there...)
That fuse drives the two (left + right) relay *coils*, and also powers the under-seat SKREEM module.
There are a number of typos in that section of the manual (splice S226 confused with (mythical?) S227), but i still haven't found that fuse in *my* fuse list. I'm slightly suspicious that it's really fuse #5 on block 1: the brake light fuse.

--dick