maxpower wrote:
> --
>
> > wrote in message
> oups.com...
> >
> > wrote:
> > > I think the PCM (powertrain control module) in my 1998 Grand Voyager,
> > > 3.3L w/anti-theft is bad, and I'd like to swap in one from a junk yard.
> > >
> >
> > Update on this. I searched for compatible engine computers online:
> > http://www.car-part.com/
> >
> > and found 10 or so. There was a huge variation in price, from $500 to
> > $65, I ordered the $65 unit from All West Coast Auto Wrecking in
> > Washington.
> >
> > They sent me the wrong part, a transmission computer. Easy mistake to
> > make, that one is on the right fender, the correct part is mounted on
> > the left fender. I figured I'd get the run around, but they said they
> > had the right part, and just send back the wrong one, which I did. I
> > expected it to take a week for them to receive my package and send me
> > the correct part, but they shipped without waiting so I got it in 3
> > days.
> >
> > I plugged it in, and it fixed the problem. So I guess I still have to
> > buy one from the dealer with the correct VIN programmed, but I can take
> > my time and won't have to pay a fortune for troubleshooting and having
> > the wrong parts replaced. In fact, I may take a crack at the bad
> > computer. I'm an electronic tech by trade, if I can get the potting
> > compound off I may be able to troubleshoot it. I suspect a voltage
> > regulator, since the problem affected all parts of the computer.
> >
> > Oh, I should mention that in searching the net, I found that a lot of
> > people with a similar problem had fixed it by reflowing the solder on
> > the instrument cluster connectors. There was a ground that tended to
> > crack on the 1996-2000 minivans. Their van would suddenly quit and
> > refuse to start, and they could get it going by pounding on the dash.
> > So I pulled the instrument cluster, but could see no fractured solder
> > joints. I reflowed the solder on the cable connectors anyway, but it
> > didn't help in my case.
> >
> > Hope this helps someone down the road with one of these problems.
> > -Paul
> >
>
> Actually if you take the back cover off, plug the PCM back into the vehicle
> and wiggle the aluminum tower like thing that looks like cooler (I have no
> idea what it is) the engine will probably start and run until you wiggle it
> again, this is a common problem with those PCM's. Even the ones that MOPAR
> Remanufactures (by a sublet company) get put back out on the market with
> these problems. Try it and let me know if it starts
>

That's a good tip, I can see you know your stuff. I tried that already,
I found some info online that said the solder joints on the connectors
can crack, so I was in there pushing on everything thru the potting
compound while my wife worked the key. Didn't make any difference.

Something is drawing a lot more current than on the good computer,
though, so I have a chance of zeroing in on it. Most likely it is one
of the devices connected to the "silver towers", which are heat sinks.
The parts that get hot are mounted on them, so they're the ones that
tend to fail, and they're most likely voltage regulators. Peering thru
the amber potting compound, the one at lower left looks like a
switching power supply, it probably makes 5V out of 12V.

Thanks for the reply.

-Paul