Engine Brake

[Rick carter]

Thanks Wolfe I will be on the phone Monday morning , an do the manual test . Thanks Rick

[Skip426]

I haven't got wiring info for a 2004 Freightliner chassis , the closest I have is 2001 and there is a dedicated fuse for the Exhaust Brake .
Can you post a photo of the fuse box you looked in for the fuse ?
I'll see how close it is to the schematics I have for 2001.

My 99 chassis also has an Exhaust brake relay in the VIM ( Vehicle Interface Module ) by the trans ECU and another Exhaust brake interrupt relay in the engine compartment .

[Rick carter]

Well I believe I included some pictures of my fuse box , SKIP426 let me know if you found the 2 pictures

[Skip426]

Ok I'm seeing pictures ; and reviewing same .

Have you opened up the Freightliner fuse box ??

[Skip426]

As I mentioned I don't have wiring info for a 2004 Freightliner chassis , but this fuse box looks to be Freightliner .

All the other fuses a National installed .

Black box with the two air lines is part of the dash gauge system MMDC.

[Rick carter]

Here are a couple more pictures , I did not see one labeled engine brake unless it has another name . Sorry for pictures sideways not sure how to rotate Thanks Rick

[Skip426]

Site computer will do strange things to photos to fit them in using the posting limits .
I find that resizing to 640 pixels before posting stops the rotating.

Test all the fuses in the red box , particularly those just labeled IGN .
I found my wipers on a fuse just labeled IGN.

These fuses can be tested in place with a voltmeter or 12 volt test light , that's why they have the metal exposed at the top.
Check both places marked with black arrows in photo , ignition key on .

If all the fuses are good then you have to get to the switch wiring to make sure it's getting power to and through the switch .

[Skip426]

Freightliner has made some major wiring changes between 99/01 and your 04 chassis .

The 99/01 fuse boxes look like this . Photo below .

The good change , I notice is that diodes are mounted in the power distribution box , rather than inline , where you have to dig into the harness and solder in a replacement .

[Rick carter]

Thanks Skip I will check the fuses I was not aware you can check them in place , I am out of town for a week an will get back into this then an will report what I find . Thanks Rick

[Rick carter]

Hay Brent I made phone calls first to Caterpillar no positive answers an suggest I call the chassis builder Freightliner an they recommended to take to a shop an have a computer plugged into it an go from there . I called Allision an they believe the switch is not on there side an also suggest take to a shop an connect to a computer .All put on hold while out of town . Thanks Rick

[wolfe10]

Freightliner should be able to send you a wiring diagram for how THEY (not Allison or Caterpillar) wired the exhaust brake circuit.


Maybe you talked with a "Customer Care" person, not a tech or engineer. SAD.

[rehlerd]

Not sure if this will work on your rig but I had a similar issue recently. I have a 2014/Phaeton on freightliner chassis with Cummins engine. I found a post which said basically to re-boot the ecm. There were 4 fuses to remove for something like 30 minutes. I decided to simply disconnect the engine batteries overnight. I did this by by turning off the disconnect switch. That worked in my case. The post I found on this stated that this would likely never occur again. Worth a try. BTY my cruise control also failed at the same time and was fixed with the re-boot.

[Rick carter]

Finally got the engine - exhaust brake fixed , finally able to get to a shop an they found the wiring had been rubbing against the air compressor an had created a short .Thanks guys for all the help . Know after picking up the MH an drive home the running lights do not shut off had to disconnect main batteries ,DAMN another project for today .

[Skip426]

Originally Posted by Rick carter

Finally got the engine - exhaust brake fixed , finally able to get to a shop and they found the wiring had been rubbing against the air compressor and had created a short. Thanks, guys, for all the help. Know after picking up the MH and drive home the running lights do not shut off had to disconnect main batteries, DAMN another project for today.

Hopefully just a stuck relay, fingers crossed.