1991 Circuit list
Posted: Wed Dec 28, 2011 11:46 am
Wiring information. This is all from my '91 B190 - yours may be different!
Circuit Number, Wire color, and items on the circuit
* As mentioned above, my fog lights were initially hooked to the unfused circuit that connects under the steering column. The fuse on the circuit for the fog lights was after the switch - so when the switch shorted out, it connected that circuit to ground. (This is why everything should have a fuse.)
* To correct that, I wired the radio - with a fuse - to the circuit, and then connected the fog lights to the now unused vehicle radio circuit, so my fog lights are now switched with the ignition, which makes a lot more sense - and I can use the radio without having the key in the ignition.
* The wiring for the power passenger seat was present and not capped off, and in fact shorted out a couple times when I grabbed the wire to check it and bumped it against something metal. Check this on yours (and the driver's seat if you don't have a power driver's seat). I put black tape over it.
* The unknown wire from that large bundle goes through the firewall into the engine compartment, then into a wire loom that seems to go all the way to the back of the camper - I was under and looking but didn't do a thorough search. (Edit 9/8/20: I believe it is power for the generator's starter.)
* There's a LOT of stuff on that first circuit! All the lights, the fans, etc. No wonder my florescent light flickers a lot. (Edit 9/8/20: Actually the light was flickering due to low voltage on the converter. All better when the converter was replaced.)
* Update 6/30/07: With shore power connected, I checked the voltage at the terminals of the fridge: 0 volts. This means the 12-volt side of the fridge is in fact wired to work only when the engine is running - which is how it should be, because it's a 10 amp draw.
Edit 9/8/20: I'll note that I replaced the fuse panel after I did this, and several other people have as well, so while the individual circuit wiring didn't change, they may be in different spots in the panel than they were when I wrote this.
Circuit Number, Wire color, and items on the circuit
- 1, Red: Florescent light, bathroom light, reading lights, bunk lights, Fantastic fan, bathroom fan
- 2, Blue: Water heater, stove fan, stove light
- 3, Brown: Furnace (I think)
- 4, Red: In mine, this isn't hooked up, but there's a red wire in the converter that's capped off. My theory is that is would be for the CB if mine had one from the factory (I added my own). It may also be for the solar panel. (Edit 9/8/20: Others have confirmed this wire is the solar panel wiring. I'm not sure how they powered the CB if it had one from the factory.)
- Acc 2, Purple: Water pump, monitor panel, 12 volt outlet (also, in mine, the refrig fan is on this circuit)
- Battery lug, Black: (Connected to the battery lug, in addition to the large battery cable, there's a smaller black wire that goes to a loose junction on the floor by the steering column) - Power driver's seat, power passenger seat (wiring there even if not equipped), one more that I couldn't identify but may be +12volts for the holding tank sensors, and in mine the CB and radio/Sirius tuner are connected there (per my own wiring; from the factory the radio is hooked to the vehicle ignition). Also, the fog lights were originally connected here in mine - which makes no sense at all. Note this connection doesn't have a fuse, so each device should be individually fused - and I'm not sure the drivers seats are!
* As mentioned above, my fog lights were initially hooked to the unfused circuit that connects under the steering column. The fuse on the circuit for the fog lights was after the switch - so when the switch shorted out, it connected that circuit to ground. (This is why everything should have a fuse.)
* To correct that, I wired the radio - with a fuse - to the circuit, and then connected the fog lights to the now unused vehicle radio circuit, so my fog lights are now switched with the ignition, which makes a lot more sense - and I can use the radio without having the key in the ignition.
* The wiring for the power passenger seat was present and not capped off, and in fact shorted out a couple times when I grabbed the wire to check it and bumped it against something metal. Check this on yours (and the driver's seat if you don't have a power driver's seat). I put black tape over it.
* The unknown wire from that large bundle goes through the firewall into the engine compartment, then into a wire loom that seems to go all the way to the back of the camper - I was under and looking but didn't do a thorough search. (Edit 9/8/20: I believe it is power for the generator's starter.)
* There's a LOT of stuff on that first circuit! All the lights, the fans, etc. No wonder my florescent light flickers a lot. (Edit 9/8/20: Actually the light was flickering due to low voltage on the converter. All better when the converter was replaced.)
* Update 6/30/07: With shore power connected, I checked the voltage at the terminals of the fridge: 0 volts. This means the 12-volt side of the fridge is in fact wired to work only when the engine is running - which is how it should be, because it's a 10 amp draw.
Edit 9/8/20: I'll note that I replaced the fuse panel after I did this, and several other people have as well, so while the individual circuit wiring didn't change, they may be in different spots in the panel than they were when I wrote this.