Electrical issues - brake lights, cruise, ASR

[stacy & maurice]

Good day all. I posted in the intro thread yesterday and gave a little background on the problem we're having but I will try to provide additional detail here in hopes of getting our next mechanic to a solution instead of a $900 repair that didn't fix everything

Introduce Yourself

2003/04 Freightliner Sprinter RV
MB Cruiser by Forest River
T1N 2500 - 158in wheelbase
OM612 - NAG1

About two months back we climbed in the cab and when we started the van the ASR light remained illuminated and I was unable to shift into gear. After discovering the safety release button under the shift lever (THANK YOU SPRINTER FORUM) we drove to the local Freightliner dealer in Anchorage, AK. We explained the problem to the mechanic, shared info from here regarding the brake pedal switch, and also told him about the other symptom we knew of at the time; no brake lights. After several hours @$145p/hr labor rate we left Anchorage able to shift into gear normally, fault codes cleared, but still no brake lights. We soon discovered that we also did not have cruise control or anti-skid (lots of driving on gravel roads). The lights, cruise, and ASR were working before the ASR indicator light malfunction.

While diagnosing the 'can't get the van into gear' issue the mechanic told us there was a short somewhere but was unable to locate. He used a ????bypass wire??? instead. he did spend some time testing other systems (cyclops, drivers side brake lights) but at $145 p/hr we couldn't afford a fishing expedition.

We are now back home in Southern California and in search of a solution. I've read numerous posts about the brake pedal switch but the mechanic that worked on our van said it tested normal. What do you think? Should we have the brake pedal switch replaced or just explain the problem to a new mechanic and have them diagnosis?

For others who have had a faulty brake pedal switch, did you also loose cruise control, brake lights, and ASR?

If anyone has any recommendations for a mechanic in San Diego, OC or south LA let us know. We've got to get this problem resolved because 1) we need brake lights and 2) we would like to sell sometime in the near future.

Thanks in advance for all the help
maurice

[Johan Turbo]

With a faulty brake pedal switch it is normal to loose several functions
- Brake lights
- Cruise control (only works after pushing the brakes once for safety reasons)
- ASR only works when you don't push the brakes.

So that mechanic did no do his work properly.

[Aqua Puttana]

Did your brake light fuse ever blow? If yes, you may find some info here.


ABS ESP Traction Lights On Brake Light Fuse (#5?) Blown
Page 13 post #122

http://sprinter-source.com/forum/showthread.php?t=4827

Good luck. vic

[stacy & maurice]

Vic - I forgot to mention the fuse. While we were on the phone with Mercedes road side assistance and searching this forum, I did check for a blown fuse. #5 was blown. I replaced the fuse and treid to start the van again. The fuse immediately blew and ASR light remained illuminated. We told the mechanic about the fuse and he was able to duplicate in the shop. I believe the ?bypass wire? that I mentioned in the orig post was run from/to fuse #5

Originally Posted by Aqua Puttana

ABS ESP Traction Lights On Brake Light Fuse (#5?) Blown
Page 13 post #122
http://sprinter-source.com/forum/showthread.php?t=4827

I'm going to re-read your post another 1/2 dozen times but I'll be the first to admit that my diagnostic skills, particularly when electronics are involved, are nil. Now that the fuse is functioning properly, what would I be looking for on the brake light assembly?

THanks again
maurice

[mendonsy]

One thing that will do it is the wrong light bulbs.
Some of them are only 5 watt rating and if they were replaced with a 25 or 35 watt that will blow the fuse.
There is a light bulb chart in the T1N database section.

[Aqua Puttana]

By-pass wire....??!! Sounds like something was done to eliminate the symptoms, but the problem was never corrected. I really haven't a clue what could have been done without actually seeing the vehicle.

Some guesses:

There is a problem in your brake light system, or trailer light system... if you have trailer wiring. To "correct" the problem (actually hide the symptoms) they disconnected some OEM wire(s) and another wire was fed to where it was needed to satisfy the computer lamp out/fuse blown monitor capability? Or maybe they just disconnected the wiring back to your brake lights and called it a "by-pass"?

The first thing I would do is try and establish if/where they removed the wire to the rear brake lights. I'd look for a loose taped off wire up near the brake light switch. This post should give you an idea of where to look for that switch.

http://sprinter-source.com/forum/sho...0&postcount=74

There is also recent additional info in Boatman's thread.
http://sprinter-source.com/forum/showthread.php?t=12569

Hopefully you will find where the wire was disconnected. If you do, restore the wiring to what it was. Don't push the brake pedal.

I would then remove both rear lamp holder assemblies and visually inspect them. They just snap out of position relatively easily. Pay particular attention to the brake light traces area (red traces in my pictures) where I found mine shorted and added the plastic insulation pieces.

Remove the brake light lamps. Visually inspect the actual lamps to see if the filaments or bases look burned or shorted. Visually inspect the lamp sockets themselves for signs of arcing.

If all that looks good, unplug the connector to each rear light assembly and keep the plugs clear so they can't short to ground (unlikely anyway).

Check that your fuse #5 is still good. If it is, try the brake pedal with the key on. Check to see if the fuse opened (blew). If it opened it could be a problem in your high brake light unit, your wire harness, or possibly a trailer wiring harness.

If it didn't open, go back and plug in ONE tail light connector. Back to the front again, inspect the #5 fuse, if still good try the brake. Check the fuse, if OK, plug in the other tail light connector and try the brake again. You get the idea. I'm trying to explain how to isolate the problem without fancy tests.

You may want to look at this post and visit Walmart to get some fuses before you begin.

http://sprinter-source.com/forum/sho...9&postcount=84

Sorry I can't be more help. Have fun. vic

042TailLightAssembly.jpg

043TailLightWiring.jpg

045RunningLightWiring.jpg

046BrakeLampSwitches.jpg

048StopLampCircWithESP.jpg

Originally Posted by mendonsy

One thing that will do it is the wrong light bulbs.
Some of them are only 5 watt rating and if they were replaced with a 25 or 35 watt that will blow the fuse.
There is a light bulb chart in the T1N database section.

You are definitely correct that the wrong lamp wattage can be a problem if you're blowing running light fuses. In this case because the brake light #5 fuse is blowing, it is unlikely to be too large a lamp wattage. Perhaps the wrong lamp forced into place could do it? The dual filament brake/running light lamp is a 21w/5w type with 21 watts being the brake filament. vic

[Aqua Puttana]

Forgot this page....

045BrakeSwitchLocation.jpg

047StopLampCircNoESP.jpg

vic