Community Forums

takethehelm · 06-28-2016, 10:39 AM

I have a 2002 34' fdds and had a problem with my engine brake not working and was troubleshooting the switch and I shorted it out. OOOps. Now I don't have power to that switch, my warning horn isn't working, my step doesn't come up when I turn on the key, most everything else seems to be working. Does anyone know of a hidden fuse somewhere or anything else that I can check? I have checked every visible fuse in the motorhome. The confusing thing is that I can't find a fuse for any of those items. Any ideas would be greatly appreciated.

takethehelm · 06-28-2016, 02:38 PM

Also my turn signals don't work although the headlights and brake lights do.

bluepill · 06-28-2016, 03:10 PM

If you google "Ignition switch wiring" you will come up with diagrams for many common designs. Based on the number of wires that attach to your switch, you can probably locate the "Accessory" and "Ignition" terminals.. Test to see if the switch is OK. The contacts may have been damaged by the short. If the switch tests OK, follow the wires to the fuse box and test from there.

DrDaveMA · 06-28-2016, 04:56 PM

The first thing to do is verify that you do NOT have a Vansco chassis. We believe that WRV did not convert to the Vansco data bus system until 2003, however the wiring diagrams have dates that indicate the drawings were used until 5/2002, so there is a slim chance that you have a Vansco coach. If you do not, then you need to determine if you have power to the switch, the wiring diagrams (see "Alpine tech library" sticky above) will help you do that.

Old Scout · 06-28-2016, 09:17 PM

Very unlikely you have a Vansco wiring/comm system--I don't know of any 03s with Vansco, 05s do for sure, and probably 04s have it too. The black fuse boxes on the bulkhead, behind the plastic panel, under the dash, in front of the passenger seat, are segregated into "switched" and "un-switched" circuits for the 12v automotive-like functions on the chassis.
PS--the solenoid for the ignition switched circuits is also located in this area, low on the bulkhead, near the floor, far right side of the opening. This is a good place to confirm that ignition switch is activating solenoid and providing switched power.....

greenmachine · 06-29-2016, 05:07 AM

Old Scout, you are right on it. You are putting him where he needs to be. If he goes to the tech library there is more on this, like wiring diagrams.
Greenmachine
2003 Alpine 38FDDS 350 Cummins ISC

takethehelm · 07-02-2016, 04:05 PM

OK. First I want to thank you for the advice. I checked the ignition switch, the ignition powered solenoid, I nearly went blind trying to follow the lines on the wiring schematics, and I'm still not getting power to my "engine brake" switch! Is there a fuse?? If there is, where is it? I solved the immediate problem by running a hot and ground to my own switch and to the engine brake solenoid so I can open and shut it at will. I'm using it but very carefully. If I can't come up with a better idea I'll wire in a new relay next to the VEC with the original relay. While troubleshooting the turn signals I ran into another problem. With the headlight switch off I'm getting a ground reading off the taillight "hot" wire but the lights work with the switch on even though I'm getting some bleed over into the ground system. I must have a weak short somewhere in the ground system, what a mess.

Old Scout · 07-02-2016, 10:38 PM

My Alpine is an early 03 which means it is probably more like a "late" 02. "Assuming" your coach is similar to mine--there are 4 black boxes with fuses and relays under the dash, behind the panel, in front of the passenger seat. In addition to these four boxes, there are three more water-proof fuse holders in the area next to the air filter, behind the last compartment door, at the rear of the coach, on the passenger side. A number of these fuses, if not all, are related to engine and tranny functions--have you checked there???
PS--ref tail light issues-- check your toad/trailer plug for shorts, or the signal light amber converter box [inline to the toad plug], that is if you have a converter.

takethehelm · 07-03-2016, 05:47 PM

Thanks Old Scout for hanging in with me. I've checked all those fuses(none of which say "Eng. Brake" at least twice. I've been inside the console behind the radio, upside down with my head up under the dash, everywhere I can think of that someone might have hidden a fuse and so far nothing related to the engine brake and I don't see one on any of the schematics. I have run a fused, switched circuit directly to the engine brake solenoid in the engine compartment and I've come to the conclusion that I haven't had an engine brake since I owned the RV. Now I know what it should have been like going down some of those mountain grades. I will probably go ahead and wire in a new relay if I can figure it all out.
As to the short in the light system. I haven't checked that converter you mention but I will do that this afternoon. What does it do? and how hard is it to get a new one if I find a problem? So far I have eliminated the driving lights and the high beams, turn signals and hazards as part of the problem. It seems to be confined to the low beams and tail lights. I'll let you know if I find a problem with the converter.

Old Scout · 07-03-2016, 08:01 PM

Just to confirm--did you find and check the fuses in the four boxes behind the panel, in front of the passenger seat? They are all related to "typical" automotive functions but may not be labelled by function. Although I was aware of the three fuses packets in the rear compartment, I only recently check them out while working on an Allison issue. To the extent that our rigs are similar, those are the only two areas I know of where chassis-related fuses are located.
The good news on solving chassis electrical issues is that neither one of us need to deal with the Vansco comm modules--that is a blessing. For non-Vansco rigs like ours, the toad/trailer plug is exposed to the weather and can cause issues. The converter box I mentioned is an aftermarket item added inline to the toad/trailer plug to "convert" the separate amber turn signals on our Alpines to the combined stop and turn signal bulbs on many tow vehicles. Bad wiring connections at that box or a failing box could cause feedback issues. Bad bulbs or sockets in the front or back could also cause feedback/shorts. Wish I had a "silver bullet" solution for you but don't. Keep me posted on your progress--hope I haven't mislead you based on differences between our two rigs......