1999 Dodge ram van. V6, 5.9L w air. I have an electrical problem that is very hard to find. The symptoms are that the engine stalls in idle after gauges in the instrument panel peg out. During one stall, a “no bus” signal was displayed in the odometer window.
The cause of the problem is probably due to overvoltage that came from the alternator. My DVM was showing more than 18 volts at one time during a wigout. We have replaced the alternator with a version that does not need a control signal from the computer, which is meant for a diesel.
After the alternator was replaced, we had the computer rebuilt, replaced the coil, replaced the idle control motor/parts, and replaced the instrument panel. It doesn’t have the overvoltage problem anymore, but the gauges still wig out and it stalls. Any ideas?

 

How are the engine to body grounds? Also are the fuseable links in good condition?

My van has a little gremlin as of lately too with the electrical. On day back in November, I pulled over to run an errand. Came back hoping in and turned the key. Everything was dead. The van chimes came on and the odometer showed "no bus". We messed with it for 30. Took the neg battery cable off, turned the key to fully on, let it sit for 30 mins, un-pluged the three connectors to the PCM and put them back in. The van started.

BUT now, the van runs fine, however the horn isn't working and the dash lights flicker unless I turn the switch a little. The airbag chine and light now comes on and off at random times. The cruise control is not working now either.

So, I can relate to some of the issues you have.

 

Steve, did you check and see if your alternator was over charging? I have posted about a similar problem in my 1999 B1500 5.2 but have received no responses on this forum. I did replace the battery ground to the block because I suspected it was broken inside the insulation. That did not solve my problem but I know now after reading in the forum I did not clear my PCM properly. Since I was just given this van I was concentrating on other issues like making sure the front end parts that needed repair were attended to. Now that those have been taken care off including new caster and camber bolts, I can address the issue of the check gauges light coming on intermittenly and finally the check engine light came on. I know I have to replace the IACM and do that in the next couple of days. Today it's 15 degrees here. Since the check engine light came on finally I had the alternator checked along with the codes at advanced auto parts and it was putting out 19 volts.

From what I have read this can be one or two things. Either the alternator is bad or the PCM. Since the lights dim and get bright and the oil gauge and alternator gauge peg when the check gauges light comes on, I want to check and possible replace the ground strap from the engine to the frame before I go further. Of course this will be after I replace the IAC and clear the codes.

My alternative is to take off the alternator and have it bench checked in the shop. I can certainly get that done from free but I do not want to do that work in the cold weather unless one of the other two solutions do not solve it. As far as cleaning the PCM contacts, there is a contact cleaner that is sold by Radio Shack and others that should get that job done. If not I would think some very fine sand paper would do it.

Funny thing, as I was traveling from Ca to Illinois (about 2000) miles in this van, I had this problem occasionally and the check gauges light would go on and then go off in a few mins. When the van hiccuped (acted like miss) it would straighten out and everything would be fine for hours on end. The exception to this seemed to be when I was in very windy conditions which makes me suspect the engine to frame ground. So I will address that first after I replace the IAC.

I do not know if a bad IAC can make the oil pressure and alternator gauge wig out, but I guess I will find out. I would think if it reports back to the PCM that its possible, as an overcharging alternator would do the same thing.

Jason

 

Dear Jason: Take care of your overvoltage problem. It will burn out your coil, like it did on my van.

 

Thanks Tom,

Its warming up to a balmy 40 something degrees today so I will be starting on it.

IAC is first.

Jason

 

Jason, I am interested in all you have found regarding the 1999 conversion. I just purchased one that "everything worked" apparently including electrical gremilins. Where do I locate engine grounding strap? And which manual do you reccomend! I am just starting out all help is appreciated! Christine

 

Its going to be difficult to help you unless you can describe the problems you are having. There is one ground strap on the alternator side. Your ground cable from your battery also acts as one.

As I answered you in email, I bought the official Dodge Service Manuals from Ebay. I bought a complete set.

Jason

 

I didn't find the factory service manuals all that helpful. They assume you know where and how to do all the tests for any problem matrix. Also I would really like some pictures.

I recently had some vacuum issues and couldn't find a decent pic or diagram of any of that stuff and the one in the hood reminds me of cave man drawings. Anyone found any of the aftermarket service manuals better than any other?

Thanks in advance,
Jimbo

 

To each there own Jimbo. Any manual assumes you have some Idea of what you are doing and is not going to teach you to be a mechanic or give you mechanical ability.

The factory manuals carry the most complete information I have found for working on a Vehicle I have found. Sorry there are not more pictures in them for you.

For example, there are electrical diagrams but unless you know how to read the symbols in the picture it does not matter. Also those diagrams might not be in the manual you are reading but the location and other manual might be referenced.

Jason

 

That's because a FSM is written for a professional mechanic to read. By comparison, manuals like Chilton or Haynes are not, so they have more easily readable step-by-step instruction along with more illustrations. With a FSM there is significantly more detailed information, but at the same time it is much hard to find that information because there is so much of it. It's one of those aggravating catch 22s!