Guys,
Within the last couple of days, while googling for help with a wiring problem on my '91 D350, I found a discussion of, and a link to a source for, a NipponDenso 136 amp, single wire, self-exciting alternator.
As I understood the discussion, the guy who posted the information was saying that this newly offered NipponDenso alternator:
a) will fit the first generation Dodge Cummins trucks;
b) makes it possible to do away with the unreliable external voltage regulator AND the original Power Control Module; and/or,
c) is just the ticket when retrofitting the Cummins engine into an application that does not have a Dodge PCM.
I am now chasing an electrical problem with my '91 (non-intercooled) D350. I just replaced the external voltage regulator yet again. The sealant goo was dribbling down the firewall from the backside of the "old" regulator which was not very old at all.
I've now removed the "Heater Control Module". Before removing this, the "WAIT TO START" and the "WATER IN FUEL" lights would shine continuously whenever the ignition key was on or the engine running. After removing this module the lights went out. This module is a $499 (plus sales 8% sales tax!) dealer item! Luckily, the truck seems to run happily without this module.
I have another electrical problem that may or not be related. The wipers began to blow their 20 amp fuse. After considerable trouble shooting, it appears that the failure appears to relate to the intermittent cycle and the high constant setting for the wipers. We've replaced the switch that goes on the side of the steering column with no improvement. We've tried to find out where this circuit "lives" as we suspect it is the root of the problem. At this point we suspect - but do not know - that the circuit is actually built into the wiper motor. The next step is to swap in another used wiper motor (from an '89 D350) in hopes that will fix the problem.
At this point I don't know that there is anything wrong with the PCM. But on the other hand, we still have not found the sucker. As of now we suspect that it is hidden inside some kind of "air box". We suspect this air box is inside the cab, under the dashboard, on the passenger side. This is the only place in or on the truck we haven't looked for the PCM except perhaps inside the fuel tank!
In summary, I don't know if these problems are separate or related. But if it becomes evident that I will have to replace the PCM, a $300 dollar dealer item, it will then become cost effective to explore whether a single wire self-exciting NipponDenso alternator might be a viable option.
Has anybody in here been there and done that or otherwise have any light to shed on this?
Thanks!
Vernon