We all want to keep our vans running well and mechanically sound. Mine is a 2001 DRV 3500 5.9 maxi.
Sometimes though we just need to rig it. It my case that would be just to get it to the shop. Problem is the only shop I know I can trust to both do the work right for a good price AND figure out the problem to begin with is 1200 miles away along a route I'm taking anyway.

I have an external voltage regulator kit to bypass the PCM coming in the mail through eBay which should do the trick. The alternator tests fine and even with a new PCM my alt. won't charge the bat. and from what I read from there I'm off to new PCM connectors and wiring harnesses that are very expensive and often seem to still not be the problem. So I need my good mechanic.

To line this trip up I'd like to know if the following idea seems sound though granted very rigged. If there's still a problem with the ext. volt reg. shouldn't I still be mobile with my camper's inverter generator running my 8 amp battery charger hooked up to the bat. while I drive? I could build up bat. for starts when parked at night and keep my accessories off when I do drive. I can't see why this wouldn't be feasible for one long highway run. What I don't know is if the 8 amp charge is enough to spark the plugs and not run down the bat.. And j suspect, but am not sure how, that I should isolate the alt. from the bat. to do this. I don't want to blow the PCM eitherThe charger is new with solid state circuitry to prevent over charge and I already have my multi meter inside the cab to keep an eye on bat. voltage.

Any ideas would be greatly appreciated.
Thanks, Art

 

Check output AT the alternator. Are you getting good voltage there?

 

Before starting the engine my bat. is 12.30v between the bat. terminals.
Crank it up and at idle speed is12.00v between those same 2 bat. terminals AND 11.99v between alternator "B+" terminal and bat. neg. terminal AND 11.98v alt "B+" and alt. casing. Alt. sticker says "Denso".

So something is wrong- too low- does this test distinguish between the alternator and voltage regulator? Seems like it just tests continuity of the heavy gauge "hot" wire. By the way battery is fairly new (6 mo. & 6K mi.).

I should say that even though I had this problem intermittently a year ago- ammeter dropping too low- it "fixed itself" and I was problem free for many months and 5K miles. All was working until I switched PCMs for an unrelated issue and after that switch this problem. I switched back to the original PCM and problem did not go away. Van has 90K mi and I have no idea if alt. ever replaced. I don't know much but because how this problem came back I'm guessing small wiring or pin issue going in or out of the PCM. I don't want to get into that and for $65 have an external voltage regulator kit on the way. If that doesn't work I guess a new alternator goes in. After that I'll be able to tell you all if we can drive our vans around with a generator running an 8amp 120v battery charger until I get to my good mechanic.
thanks

 

Unfortunately, all it tells you is that the charging system isn't working, it doesn't tell you which part has failed though. I think the easiest... way to tell, is yank the alternator off, and have it tested off the vehicle. If it works on the test bench, then, voltage regulator has failed. (which is in the PCM......)

 

thanks, I already have the external v.r. kit coming in the mail tomorrow and am going to go ahead and stick it in first. Is there the possibility this could be in the tiny wiring or connectors in and out of the PCM? Anyway seems the v.r. kit will eliminate both PCM and that wiring/connector as problem. Next the alternator.
Logistically driving around to do this stuff I'm using a little camper generator and 120v charger (puts out 14v 8a charge) only when parked to keep driving. If you know I'm still trying to find out if after I start the engine I can hook up and use that 120v charger as I drive? If I can't find advice anywhere I may have to just try it. I would disconnect the B+ wire at the alternator but don't know whether to leave that other connector (field ??) on or off the alternator. At this point I would probably just leave it on.
Thanks

 

Yeah, try the external voltage regulator, see what happens.

As for the 120v charger, I wouldn't suggest it. 8 amps just ain't a lot, considering your alternator is rated at north of 100...... I think there would be a decent chance of letting the magic smoke out, or something even more exciting......

 

Thank you but what means "magic smoke"?

 

Guess I am too much of a computer nerd.

Basically what it means is, doing that would likely burn up your charger, especially if the system tried to draw more power than 8 amps via that charger. That would make it get really hot, and possibly even burn, hence "smoke". In the computer world, it's been a running joke that 'when you let the magic smoke out (I.E. burn a component), it stops working.

 

Thanks- that tells me not to try it. I had thought the charger would just put out it's max and no more. Got my external v.r. and it goes in tomorrow. I'll post how it goes.

 

Turned out it was the alternator as "Hey You" predicted (thanks). I've got the external voltage regulator installed (bypassing the PCM) and will continue to use it. Problems with it and I'm all set to splice back in the PCM. I don't know if this is common but alternator failure was intermittent which threw me off. I mean like 5,000 mi. between issues.
Last thing I have to do is return this clicking remanufactured alt. to Autozone and get a new one.
Thanks