Happy to be Back in the Barn

First time I've ever had a Prevost towed. We left for Tampa Monday morning and got five miles from the house. I saw I was having a problem and planned to get off the road on the other side of the red light I was approaching. Lost power to my transmission shift pad , the speedometer ceased to work, Check Engine and Check Transmission lights came on and engine died while stopped at a red light. Engine would not restart. After a few hours, we were towed to a local authorized Detroit Diesel truck repair shop.

While waiting on the wrecker, I called PASS and went through several diagnostic checks but was not able to isolate the problem. It was a little difficult to trouble shoot while standing next to the fast lane with my electrical compartment open, holding a voltmeter and dodging traffic, but we did determine that I didn't have a blown breaker or bad relay. The first picture makes it look like I was sitting on the inside lane, but that's not the case. The fast lane was on the left side of the bus. My CRV is sitting in a turn lane on the right side of the bus.

I left the PASS phone # with the shop because I knew they would need it. They finished the diagnostics/repairs Wednesday. The service manager told me they talked with the PASS technician five times. The problem was a loose wire between the battery and the ECM. The tech at the repair shop was off until next Monday, but he is supposed to call me and tell me exactly where the loose wire is located. A very small and seemingly simple issue that resulted in rather catastrophic results.

If I could have been towed back to my house, I think I could have worked with PASS, and eventually got the problem solved and saved myself a lot of money. Unfortunately, I have a steep driveway, and I was afraid I would have some serious damage to the rear of the bus if the wrecker pulled the bus up the driveway with the front raised.

I am very thankful that I was close to home when this happened, and it is good to have the bus back in the barn.

Hi Dale. So sorry to hear you had trouble but glad you and Paulette are safe. Ruth Ann and I missed you at Parliament.

Thanks Denny. We were looking forward to being there, but sometimes things don't go the way we plan. That Masterplan sometimes supercedes ours.

Yes Dale sorry you didn't make it this year. As usual Parliament has done a great job hosting the Rally. Lots of stories told and people to see. This years recipient of " Most Things Fixed " on their Bus is Roger Foster. Without Miles in attendance the daily question was " Who has Gil now. "

What Road Service club did you use ? Did they pull the driveshaft or axle ? How did they run the air line to your Bus ? It sure would be nice to know which wire shut you down,

I'm gonna guess a bad or corroded connection at the batteries where the 2 yellow 12 gauge wires for the computer that's where they start and I've seen that problem there on truck chassis?

Guess 2 the multiple pin connector at the ecm

Jim,

My misfortune was Roger's blessing. I'm sure if I had been there, I would have been competing for Gil's time and expertise also. Worked out good for Roger. Maybe I'll send Roger a bill!!

I used Coach Net, and they sent the right wrecker service the first time and kept me informed every step of the way. I am glad I had changed to them in August.

Because I was sitting in the middle of a busy four-lane highway, and the bus was on a slight incline, the driver said it would be better to pull the driveshaft. I was a little concerned about him crawling under the bus several times, but he got the job done in a professional manner.

Since I don't have an air connection at the front of the bus, he removed the drain valve from my front tank and installed a fitting to attach the hose. I need to fix that by installing a fitting in the outside compartment under driver's seat.

I am reasonable sure it was a wire directly attached to the battery from the ECM. At one point, the Service Manager said the wire was on the battery then said he wasn't sure. I'll let everyone know when I hear back from the Tech next week.

Quote:

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Originally Posted by Joe Camper

I'm gonna guess a bad or corroded connection at the batteries where the 2 yellow 12 gauge wires for the computer that's where they start and I've seen that problem there on truck chassis?

Guess 2 the multiple pin connector at the ecm

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Joe,

I'm pretty sure you are right. As I stated in an earlier post, the Service Manager said it was at the battery then said he wasn't sure. While I was talking to the PASS Tech, I mentioned the multi-pin connector on the ECM, but he didn't seem to think that was the problem, so I didn't check it. Hopefully, if anyone else ever has this problem, or a similar one, someone will remember the solution and save them a bunch of trouble and expense.

Dale,

I'may glad you are safely back home.

Unless it was the crimp terminal connector, your battery connections did ot look bad last I looked at them. Given your chassis batteries were moved from the factory location my money is on the splice where they may have lengthened the wire or the ECM connector where they may have installed a new longer wire.

Gil, I'll check the splice and the battery connection to see if I can determine where it was tightened. I got under the bus this afternoon to make sure they had reinstalled my drive shaft correctly and filled both grease fittings. Fortunately, they had done it right.

I had always assumed that the wrecker driver reinstalled the drive shaft or axle when they towed you to a shop, but it seems to customary that the towing company removes it and the repair shop replaces it.

As the picture shows, I have one battery with two 10 or 12 gage yellow wires and 4 black wires. Another battery has one 12 gage yellow wire and 2 black ones. I talked with the tech who worked on the bus, and he said it was one of the small wires on the battery that was loose. I asked if it was the two yellow wires that are connected together, and he said it wasn't. It was either the black wires that are connected to the battery that has the 2 yellow wires on it or it was the single yellow wire on the other battery.

Unfortunately, I found some corrosion on the terminals, so I removed them and cleaned them. The shop must have just tightened the nuts without cleaning the terminals. Guess I shouldn't have expected too much for only $910 worth of diagnostics. No parts involved.

Gil, I believe you said the two yellow wires go to the ECM? Do you know what the other single yellow wire goes to?

Hopefully, if anyone else ever loses the lights on the transmission shifter pad, they will know to start looking at the ECM wires on the battery.

I would be guessing, but would guess one goes to the DDEC and the other to the transmission computer. BTW, it'seems strange you have 2 black return wires for each yellow hot or supply wire.

Thanks for the update Dale. Lots of people watched this Thread.

Here's the wiring information. It looks like they are all DDEC wires.

Attachment 13872

I wonder why they decided to run two of the positive wires to one battery and one positive wire to another battery? I really don't understand why they needed a total of six negative wires? Based on the diagram, where would two more negative wires go?

I'm not a fan of putting a lot of connections on a battery post. Maybe, they weren't either. This might explain why the coonectors are on different batteries. BTW, the positive connections are only separated by a battery interconnect cable. So you can consider they are at the same point. At least one negative connection appears to be in the wrong place. They should be connected to the battery terminal that goes to chassis negative. It appears that in one case it is going to the split pair of batteries.

A better question is were are the fuses, assuming there are fuses..

I just looked at mine it is wired very similar to yours. I didn't dig deep, but it was not obvious to me that these connections are fused.

I dont see any fuses on mine either.

Is the ECM the control box for DDEC? Im not sure of the difference in terminology?

Dale, have you had good luck with this issue not returning since your coach was towed? I have a 96 Country Coach XL40 that I am trying to go through as best I can at home right now to try to lower my chances of problems this summer. Did any of you guys find and/or add fuse protection here?