1999 Freightlinerl Ambulance/Camper Electrical issues

[ksgreywolf]

I have a 1999 Freightliner former Bariatric unit that I have slowly converted over to a camper. It has the 5.9 24v Cummins and Allison automatic transmission. I've had her for about 2 years now and the other day I had a major problem that I'm hoping someone in this forum can help me figure out. I had driven her for about 50 miles with no problem. Stopped at a stop light and when it turned green she had no power, the best I could do going up an onramp was about 7 mph. I pulled over and checked the normal stuff but found nothing out of the normal. I limped back home and have gone through all the mechanical stuff I can think of. The lift pump is working correctly and giving me good pressures. Same with the VP44 HP pump, I checked the turbo and she spins free and clear with no "wiggle" at all. I did find a couple fuel leaks that I fixed. I went out the next day and started her up and she ran like nothing happened.
The one thing I remember looking at while the "event" was happening was the amp meter. She was drawing a tremendous amount of amps, around 80 amps +/-. During the event when I pushed down on the accelerator I could see the amps rise and if I push down at a certain point I could hear a clicking sound under the hood. I couldn't locate it and haven't heard it since. During normal operations looking at the amp meter she fluctuates +/- 1 amp but mainly stays at 0 amps.
This one has me baffled. I'm open to any and all suggestions.

 

[Ozrockrat]

There are 3 fuses that come directly off the battery. Check those 1st. Also you should be able to check for error codes on the dash pane. It sounds like you are in limp mode. Is there a check engine light on at all?

 

[ksgreywolf]

I will check the fuses. The check engine light came on a couple times when I was having the issue. But nothing now or since. As for limp mode nothing now, full power.

 

[ksgreywolf]

Fuses checked out ok.

 

[Brewdiak]

I always check for loose grounds when dealing with electrical gremlins but no specific ideas for you sorry

 

[Ozrockrat]

They did have an issue with the oil pressure senders on that engine. Cummins fix was to replace the sender with a switch and reflash the ECU to show a set pressure. I did track down a different Cummins part that fits and does not require a reflash. But that low oil pressure will put it into limp mode and will not hold the check engine light once the power is recycled so it is hard to trace without a code reader.

 

[ksgreywolf]

I went through a lot of your forum and saw the silverleaf software and I ordered it. Hopefully I can find out more once I receive it.

 

[Ozrockrat]

Is it fixed yet?

 

[rossvtaylor]

As an owner of a 99 Freightliner, also, I am following along to learn more about what you find.

 

[ksgreywolf]

As it turns out the problem that I had was not an electrical issue. To be honest I have not found the root cause of the problem. What I have done so far. I found that the injection lines to cylinder 1,3 & 6 where loose probably allowing some air. While driving the injector line for cyl. 1 broke off the VP44 pump and had to replace. Many of the injection line brackets were missing and am in the process of replacing. In reading the blog from Ozrockrat he talked about the Silverleaf software. I purchased it and have been running it. But I wasn't satisfied with it. Not sure if it's the program on the truck. But I constantly get the failure between jib and engine. In troubleshooting that it tells me that there is something wrong with my ECU. So I forked out the bucks and got an inline 6 kit and Quickserve from Cummins. I just figured that with all the things that seem to be going wrong in the engine I had to have some failure codes lingering in there that the Silverleak software wasn't finding. But when I hooked up the Cummins software it shows no failure codes, BUT it has no problem with communicating with the ECU, but Silverleaf does.
With the Silverleaf program it is constantly giving me erroneous info. For instance I open the program and start rolling down the road. It shows my speed just fine, fuel tank level, odometer reading, engine hours etc. I look over and now the odometer reading has gone from 204,000k miles to 6 million miles, fuel gauge goes from a fuel tank size of 50 gallons to 64,000 gallons, engine hours from 10k hours to 48k hours. No turbo boost pressure to 14 or 7 or 1 psi. Nothing stays constant. Again when I hook up the Cummins I don't have the same issue. But trying to read rolling information on Quickserve is a pain, the display with Silverleaf is by far more superior but the information is unreliable. So I'm not sure what is going on with the computer and ECU or engine.
My newest problem that just popped it's ugly head up last night is the air parking brake. I left work in the truck and everything was fine. Stopped to fuel up and the air park brake won't engage and the truck won't stay still and wants to roll away. I live in the mountains in Colorado so there isn't a flat spot anywhere. So having the air parking brake is a most and I can't jump out with it rolling trying to block the wheels.
Also last weekend the turn signals and emergency lights stopped working. So I have no turn signals. I replaced the flasher unit to no avail. I've searched for a fuse or breaker to replace but have found nothing that appears to be the issue. I was supplied some information on the vehicle from the ambulance service that I bought it from, but not enough to get a good clear picture of the truck. I've reached out to both Freightliner and Horton for assist and to date they have ignored me.
I've had this ambulance for 2 years now and I'm at a point where I'm about to just get rid of it and try something else. I know the wife is tired of me spending money on it. It's great as a camper, it has everything I want/need. But I'm about to pull my hair out with all these constant issues.

 

[ksgreywolf]

Luckily the parking brake was an easy fix. The bolt fell out connecting the cable to the brake.

 

[Ozrockrat]

Get in touch with the guys from Silverleaf. They answered my questions in a reasonable timeframe.

I have used my Silverleaf setup on 3 trucks with only minor hassles to do with the display not the information it collected.

 

[ksgreywolf]

Thanks Ozrockrat. Any suggestions on the turn signals?

 

[Ozrockrat]

Fuse 25 and it is 20 amps.

Wiring diagram in the service manual is basically useless unless you have perfect vision. I have trouble reading them even with a magnifying glass.

But go back to basics. Check fuse. Check power at the indicator switch and hazard flashers. Then work your way outbound.

Don’t assume it is an Ambulance thing until you prove it actually is not the core truck wiring first.

 

[ksgreywolf]

Thanks much. I will check this out once I return from Antarctica. I'll be down there for 3 months and return in July.