Remote Start Panel Wiring 1993 U280

Topic: Remote Start Panel Wiring 1993 U280 (Read 596 times) previous topic - next topic

Remote Start Panel Wiring 1993 U280

August 24, 2023, 12:09:58 pm

This request aimed at fellow GV owners. I let our coach sit in one spot (in our driveway) for too long, and some pack rats decided to move into the engine compartment. The rats are dead (Thank You Tomcat snap trap) but the damage now requires repair. They attacked the wiring at 3 points. Near ground level, they chewed through my alternator SENSE wire. That was easily fixed with a splice. Higher up on the engine, they completely removed the air conditioner compressor clutch power wire, and also pulled some wires loose from the Remote Start panel. My questions are as follows:

1. I haven't used the dash A/C for the last 8-9 years, so the compressor wire is not critical. Still, I would like to repair it if possible. The rat didn't leave me much of a wire stub (see photo), so it may be tricky splicing in new wire, but my question is: where does the power wire connect to a wiring harness? I think the piece of wire in the 2nd photo below is the chewed-off power wire. It has a male plug type connector on the end, but I can't find any matching female connector anywhere close by the compressor. Can anybody tell me where that wire connects on their coach? A photo, if possible, would be a great help.

2. Second question concerns the wires going to the remote start panel. See the photos. I have 2 wires that are pulled loose, and I'm not sure where they connect. They both have female spade connectors. The RED wire is labeled B71 and it is hot all the time. The BLACK wire is labeled B72. On the panel I find two "open" spade connectors - one on the ENG ON/OFF switch and one on the OIL PRESS light. I am GUESSING that the disconnected red wire goes to the ON/OFF switch, and the black wire goes to the OIL PRESS light, but I'm not sure...it could be the other way around. My 12V Wiring Diagram refers me to drawing A-4752 Remote Start. I found that drawing in the excellent Forum library, but it must be for later model coaches. It doesn't match the setup on my coach. SO, if anyone has the same panel as my coach, and can take a look at the wiring to verify where the RED and BLACK wires connect, I would really appreciate it. THANX!

Re: Wiring Assistance Request 1993 U280

Reply #1 – August 24, 2023, 12:26:33 pm

My ac compressor wire comes from a relay mounted above the cruise panel in the engine compartment.

Re: Wiring Assistance Request 1993 U280

Reply #2 – August 24, 2023, 12:55:51 pm

Thanks, Mike, but I think your coach is not very similar to ours - different engine, chassis, etc. I don't have any relays anywhere near the A/C compressor.

Re: Wiring Assistance Request 1993 U280

Reply #3 – August 24, 2023, 01:00:40 pm

Chuck,

On some of that vintage, the relays, etc were on a steel plate often located behind driver's rear wheel.

Many of us moved that plate and all its components to the front of the engine compartment OR into the "electric area" at the foot of the bed.

Re: Wiring Assistance Request 1993 U280

Reply #4 – August 24, 2023, 01:01:27 pm

The compressor relay should be behind the left rear wheel on the same panel as the battery isolator. The red wire that is hot all the time should go to the on off switch. I don't know about the other wire.

Re: Wiring Assistance Request 1993 U280

Reply #5 – August 24, 2023, 01:42:09 pm

If the ac worked , you may be able to find the relay by having a helper turn the dash switch on and listen for a click. Lots of things interrupt the circuit tho. High and low pressure switches etc.

Re: Wiring Assistance Request 1993 U280

Reply #6 – August 24, 2023, 02:23:35 pm

I appreciate the suggestions, but you guys are misunderstanding my question. I know where the A/C relay is mounted (on the isolator panel). I'm not trying to get the A/C working...I'm just trying to repair the short 6" long damaged wire that the rat chewed up (see the photos in my initial post). The original compressor clutch power supply wire wire came directly off the compressor and within about 6 to 8 inches it must have been plugged into a female connector. I just can't find that connector or where it is hidden in a nearby wiring loom. That's what I'm asking about...

Re: Wiring Assistance Request 1993 U280

Reply #7 – August 24, 2023, 02:30:09 pm

Quote from: red tractor – August 24, 2023, 01:01:27 pm

The red wire that is hot all the time should go to the on off switch. I don't know about the other wire.

Thanx Ron! That is what I was thinking, but very glad to hear verification from a knowledgeable source! In that case, the black wire (most likely a ground wire) must go to the oil pressure light.

Re: Wiring Assistance Request 1993 U280

Reply #8 – August 24, 2023, 03:08:00 pm

Sorry to learn of your rodent residents.

Our coach A/C compressor clutch 12v wire is plugged into a low-pressure switch that is located nearby on one of the refrigerant hoses connected to compressor. The other wire on the low-pressure switch is connected to a high-pressure switch located a little further away on the same refrigerant hose. The other wire on the high-pressure switch is connected to the relay you are aware of on the isolator pane. Both pressure switches have to be closed for compressor to work. Some coaches combine the two pressure switches.

Removing compressor P-clamp over power wire will allow more room to make a good splice.

Re: Wiring Assistance Request 1993 U280

Reply #9 – August 24, 2023, 03:54:46 pm

Quote from: Barry & Cindy – August 24, 2023, 03:08:00 pm

Our coach A/C compressor clutch 12v wire is plugged into a low-pressure switch that is located nearby on one of the refrigerant hoses connected to compressor.

Removing compressor P-clamp over power wire will allow more room to make a good splice.

Thanx Barry for the clue, but in this case no joy. I don't have any pressure switches on the refrigerant hoses near the compressor. On our coach the pressure switches are both located on the lines up in the nose of the coach under the passenger side "hood".

But I will remove the clamp on the wire to make a splice, once I figure out where the other end of the wire connects. Still a mystery!

Re: Wiring Assistance Request 1993 U280

Reply #10 – August 24, 2023, 05:10:48 pm

Hello. Maybe this helps... but mine seems to have some extra jumpers on the remote start panel. Sorry on the AC, I can't see where it goes since it's all wrapped up in wire shielding.

Re: Wiring Assistance Request 1993 U280

Reply #11 – August 24, 2023, 06:47:03 pm

Quote from: Huginn – August 24, 2023, 05:10:48 pm

Hello. Maybe this helps... but mine seems to have some extra jumpers on the remote start panel. Sorry on the AC, I can't see where it goes since it's all wrapped up in wire shielding.

Thank you Huginn! Your photos are actually VERY helpful. The first one verifies Ron's statement that the "always hot" RED wire does belong on the ON/OFF switch. (I also have those extra jumpers behind my ON/OFF switch...I just didn't mention them) Your 2nd photo gives me an excellent clue where to look for the elusive female plug connector. I have that exact same large plastic wire shielding running behind my A/C compressor. I did take a quick look inside the shielding and didn't see anything, but tomorrow (when it is cooler) I will do a more intensive search.

Our coaches are nearly litter mates - only 13 build numbers apart.

Really appreciate you taking the time to post!

Re: Wiring Assistance Request 1993 U280

Reply #12 – August 24, 2023, 08:26:26 pm

Glad it helped! Yes, very close build #s.

Re: Wiring Assistance Request 1993 U280

Reply #13 – August 25, 2023, 03:18:06 am

Just throwing out a thank you to Huginn for the remote start pic. Mine hasn't worked due to an old engine fire but now I think I can fix.

Re: Wiring Assistance Request 1993 U280

Reply #14 – August 25, 2023, 12:05:50 pm

Success! Another big THANX to Huginn for posting the photos.
I went back and took another look at the large split ribbed wiring protection tube that runs behind my A/C compressor. That stuff is VERY stiff (almost petrified) from 30 years of engine heat - takes major effort to pry it open. But I finally prevailed, and using a bright LED light I was able to locate the female connector hiding among the other wires. So I now know where the chewed-off wire from the compressor terminates, and it will be a simple job to splice in a new wire section. Could not have solved this without the highly valued help from Forum members!

Re: Wiring Assistance Request 1993 U280

Reply #15 – August 25, 2023, 01:01:47 pm

Quote from: Bob & Sue – August 25, 2023, 03:18:06 am

Just throwing out a thank you to Huginn for the remote start pic. Mine hasn't worked due to an old engine fire but now I think I can fix.

Robert,

It may be helpful to your project if I summarize what I have learned about the wiring that connects to the Remote Start panel and adjacent Hobbs hour meter. Referring to the photos below, and to the photos in the earlier posts in this thread, you can see that the wiring bundle going up to the panel contains 6 wires. They should be connected as follows:

The larger gauge RED wire (B71) goes to the bottom spade terminal on the Engine ON/OFF toggle switch. This wire is HOT all the time!

The BLUE wire goes to the top spade terminal on the Engine ON/OFF toggle switch. This blue wire has two jumper wires (also blue) that split off at the spade connector. One of these jumpers goes to one of the spade terminals on the OIL light. The other jumper goes to one of the screw terminals on the START button. It is very hard to see these jumpers because they are hidden behind the panel.

The BLACK (B72) wire goes to the second spade terminal on the OIL light.

The BROWN wire (23) goes to the second screw terminal on the START button.

The smaller gauge RED wire and the GREEN wire go to the Hobbs hour meter.

Looking on my copies of the B-2037 and B-2126 12 volt wiring diagrams, I can locate references to the sources for the RED (B71) wire, the BROWN (23) wire, and the RED and GREEN wires going to the Hobbs meter. Where the other wires originate or terminate is (to me) a mystery.

After I got my wires reconnected, I flipped the ENGINE toggle switch to ON. I heard a solenoid click, which I believe is the AUX START solenoid located on my isolator panel. I think that is where the BLUE wire goes when it leaves the ON/OFF switch. At the same time I heard the solenoid click, the red OIL light came on. I believe this light will stay on until sufficient oil pressure builds after engine start, at which time it will go out. I then pushed the START button, and the engine cranked over! IT'S ALIVE!!!!!

NOTE: There has been past discussion on the Forum about "Does the ignition switch on the dashboard have to be turned ON to allow the REMOTE START panel switches to work?" In the case of my coach, it does not. The only way to determine this for sure is to test it on each individual coach.

Re: Wiring Assistance Request 1993 U280

Reply #16 – August 25, 2023, 01:39:13 pm

Thanks Chuck. As usual , you go above and beyond. I appreciate it. I'll be moving the remote start up the list now.

Currently I'm finishing up the hard plumbing to the little buddy heater in the coach and tweaking my install of a radiator water sprayer for those HOT climbs and steep downgrades.
Thanks again.

Re: Remote Start Panel Wiring 1993 U280

Reply #17 – August 25, 2023, 04:03:03 pm

I edited the title of this thread to facilitate future searches for this subject.

Re: Remote Start Panel Wiring 1993 U280

Reply #18 – August 25, 2023, 07:03:45 pm

While I was working at Foretravel of Florida, we had a new coach stolen off of our lot because of the crooks being able to flip the on switch and start the coach from the back. That coach was finally found a year later with nearly 100,000 miles on it. Never did catch the crooks. After that Foretravel changed to where the ignition switch had to be on for the remote start to work.

Re: Remote Start Panel Wiring 1993 U280

Reply #19 – August 25, 2023, 07:40:03 pm

Quote from: red tractor – August 25, 2023, 07:03:45 pm

While I was working at Foretravel of Florida, we had a new coach stolen off of our lot because of the crooks being able to flip the on switch and start the coach from the back.

Interesting. Having never tried this, I am just armchair theorizing... Even if the engine could be started from the remote panel, how would the thief get the transmission into gear, and get the suspension into travel mode? The ignition switch needs to be in the "run" position for both those things to happen. Of course, if the thief had knowledge of the Foretravel electrical system, they could always hot wire (or bypass) the ignition solenoid, which I think would then activate the Allison control panel and HWH panel.

Re: Remote Start Panel Wiring 1993 U280

Reply #20 – August 27, 2023, 08:21:48 pm

I don't know either, but they were able to drive it away. I think it is strange that it could have been traveling for a year before being found.

Re: Remote Start Panel Wiring 1993 U280

Reply #21 – August 27, 2023, 09:52:07 pm

Quote from: red tractor – August 27, 2023, 08:21:48 pm

I don't know either, but they were able to drive it away. I think it is strange that it could have been traveling for a year before being found.

Ya, hard to be 36+' and STEALTH!

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