GM question....

i'm not completely checked out on GM cars anymore. that's why i like my fords.
but, back to the problem. here's what's going on....
son's vehicle:
1995 pontiac transport - 3.1 engine.
problem: was driving - everything was ok. pulled off interstate and came to stop sign at night. the lights dimmed, the electrical gauge dipped from normal voltage level into the red, which is around 9 volts and it stayed there. i live three miles away, so they drove to my house in hopes of fixing it.
what i've found out so far: did the usual checks. belt is ok, took alternator off and had it tested - checked out fine. battery also checked out fine. looked at hayes book, couldn't find much in charge circuit information, other than what we checked out.
next step - tried to change symptoms. put battery voltage directly to the positive post on alternator to make sure that it wasn't a fusible link that had opened up. no change.
with the engine running, pulled cable off battery and engine died immediately.. alternator not outputting at all.
anyone got any ideas on where to go from here??? wiring all looks fine. no strange smells or odors. just doesn't charge.
thanks in advance,
~ curtis
knowledge is power - growing old is mandatory - growing wise is optional "Many more men die with prostate cancer than of it. Growing old is invariably fatal. Prostate cancer is only sometimes so." http://community.webtv.net/PALMER_ENT/doc
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"c palmer" wrote: (1995 pontiac transport 3.1L)
pulled off interstate and came to stop sign at night. the lights dimmed, the electrical gauge dipped from normal voltage level into the red, which is around 9 volts and it stayed there. drove 3 more miles home.
did the usual checks. belt is ok, took alternator off and had it tested - checked out fine. battery also checked out fine. put battery voltage directly to the positive post on alternator to make sure that it wasn't a fusible link that had opened up. no change. with the engine running, pulled cable off battery and engine died immediately.. alternator not outputting at all.
wiring all looks fine. no strange smells or odors. just doesn't charge. anyone got any ideas??? __________________________________________________
Things to check:
___ Broken wire or corrosion in alternator field plug. ___ Failed alternator field activation relay. ___ Broken shift key on keyboard. ___ Actual voltage readings on vom. ___ alt.autos.gm
Good luck.
Rodan.
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pulled off interstate and came to stop sign at night.   the lights dimmed, the electrical gauge dipped from normal voltage level into the red, which is around 9 volts and it stayed there. drove 3 more miles home. did the usual checks. belt is ok, took alternator off and had it tested - checked out fine.   battery also checked out fine. put battery voltage directly to the positive post on alternator to make sure that it wasn't a fusible link that had opened up.   no change.   with the engine running, pulled cable off battery and engine died immediately..   alternator not outputting at all. wiring all looks fine. no strange smells or odors. just doesn't charge.       anyone got any ideas??? __________________________________Things to check: ___ Broken wire or corrosion in alternator field plug. ___ Failed alternator field activation relay. ___ Broken shift key on keyboard. ___ Actual voltage readings on vom. ___ alt.autos.gm Good luck. Rodan.
===> thanks rodan for the suggestions.
- Broken wire or corrosion in alternator field plug - haven't found anything so far..... using the vom...
---Failed alternator field activation relay -> haven't found any relay. i'm interested on where it would be. i have traced the prints. there is a 15amp fuse labelled 'ignition fuse' and that is suppose to be where the field voltage goes to the alternator. also found a box of fusible links, but they checked out.
- Broken shift key on keyboard. -> good one :)). actually started a while back, where the shift key stopped operating. got use to just typing away without worrying about the shift key.
so, far, here's more on what i've learned. i've did different web searches on pontiac transport to see if this is a common problem and did not find a single reference to a charging problem. closest thing was on starters or starting circuits. so, i'm thinking that i'm looking at an isolated case, which is why i was hoping that someone might have ran across a similar situation on a GM type vehicle.
again, i really appreciate the input.
~ curtis
knowledge is power - growing old is mandatory - growing wise is optional "Many more men die with prostate cancer than of it. Growing old is invariably fatal. Prostate cancer is only sometimes so." http://community.webtv.net/PALMER_ENT/doc
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On Thu, 19 Jun 2008 18:19:23 -0500, PALMER snipped-for-privacy@webtv.net (c palmer) wrote:First of all, being a 1995 Trans Sport are you ONE HUNDRED PERCENT SURE it is a 3.1? From what I remember, ALL 1995 Trans Sports were 3.8 in Canada (and the USA?). Only Ventures got 3.1 engines.(At least I've never seen a 3.1 1994 or 1995 Trans Sport in Canada, and I've picked over all the local "grave yards" keeping mine (1994) on the road (until I buried it 3 weeks ago)
If it IS a 3.8, not a 3.1, the regulator is in the PCM.
If it IS a 3.1, the feild is fed on the F terminal by a brown wire from the 15 amp ignition fuse (shpould be "hot" with the key on). There is a connector on the engine side of the firewall that has been known to corrode on both the 3.1 and the 3.8.

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are you ONE HUNDRED PERCENT SURE it is a 3.1? From what I remember, ALL 1995 Trans Sports were 3.8 in Canada (and the USA?). Only Ventures got 3.1 engines.(At least I've never seen a 3.1 1994 or 1995 Trans Sport in Canada, and I've picked over all the local "grave yards" keeping mine (1994) on the road (until I buried it 3 weeks ago)
===> i WISH it was the 3.8 they are almost a bullet proof engine. this one is a throttle body 3.1.
--

If it IS a 3.1, the feild is fed on the F terminal by a brown wire from
the 15 amp ignition fuse (shpould be "hot" with the key on). There is a
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On Thu, 19 Jun 2008 21:44:07 -0500, PALMER snipped-for-privacy@webtv.net (c palmer) wrote:

Like I said - bad bulkhead connector between instrument panel and engine harness. It's a bolt-together connector on the engine side of the firewall.
The 3.8 isn't totally bullet-proof either, but a much better engine than the lousy 3.1
First engine in mine went at 275,000km - just before I bought it. The factory rebuilt engine I had installed blew up spectacularly at about 97,000 km 3 weeks ago.
Anyone need a full set of factory manuals for 1995 TransSport? $25 plus shipping from Waterloo Ontario.

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c palmer wrote:

Sounds like a bad ground or connection somewhere.
Jeff

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