DTP a gentlemen and a scholar

[Big Jeff]

It was great to meet you this weekend and thanks for the tips, nice to know there are some good guys around when you’re out on the water. Hope your son does well in B-ball. I had a good time out there, but how can’t you with some saugies a few eyes and some good old black berry! Good luck out there just wanted to give you a little good press…keep catching um!!!!!

[Jeremy airjer W]

You two definitely have a gift for chat. Not that I was eves dropping or anything. I would have introduced myself but I couldn't get a word in!

[Soul_Patrol]

I Have to thank Big Jeff for taking me with him on Saturday morning for a great time fishing. Speaking of the chatting that goes on out there, funny thing in the morning I counted 23 boats with in a stones throw and you could hear a pin drop out there. I guess no one had anything good to say.

[tberrict]

What's up Big Jeff and Soul. Glad you are not rookies anymore. One of these days I will have to come and show you how to catch the pigs. :-) Maybe I will get my deer early, and teach you how.

[dtp]

Airjer,

Sure is easy to talk when fish are biting - but have a problem that you may be able to comment on.

My buddy has a 2002 Impala 3.8l - died - dead battery. Had it diagnosed - bad alternator. Pulled alternator had A&S check before rebuilding. Alternator passed just fine - 14.4 V full load. Put back in - no output. Only 3V at back lug. My Ford has 12V. Brought to Luther Chev - claim bad PCM or something like that - $650 - tried it - no difference. Then they say bad alternator. Put old PCM back in. Questioned the 3V thing and they said that is the way it is. Could the 12 V A&S trial give us a wrong result? Just a bad regulator?

He had a rebuilt engine installed at John's 6 weeks ago - nothing but trouble since - not the engine but little nitpicking things. Could it be a bad wire/ground?

Do not have any repair manuals for it.

DTP

[Jeremy airjer W]

You had 3 volts at the big battery positive cable thats bolted to the back of the alternator?

If this is correct than there is a definite issue with that cable. With the battery connected there should be twelve volts on that wire no matter where you test it.

If you check the voltage at the battery there is twelve volts right?

What happens to the voltage if you remove the cable from the alternator. Does it go back to 12 volts or does it stay at 3 volts?

Make sure that the ground straps near the starter on the bell housing bolts are tight. If there is a bad ground this could give similar symptoms. With a voltmeter put one lead on the negative side of the battery and the other end touch anything metal on the engine. if it reads anything from 1 to twelve volts than a ground is bad.

I assume you checked the cable ends at the battery for corrosion, very common! and you checked the voltage of the battery with the cables disconnected. should read a little over 12 volts.

how many wires does the plug in connector on the back of the alternator have? Typically if it is PCM controlled then a scan tool will be needed to energize that wire.

Does the vehicle start and run?

I think that if you probe that cable and figure out where you're loosing voltage than your problem might be solved.

[dtp]

Airjer-

Vehicle does start and run - dies after 1/2 hour with a full battery charge prior to starting. Definite battery drain. No recharge from "tested good" alternator.

Voltage at back of alternator lug is 3V connected- have not disconnected and tried yet- maybe tomorrow at lunch. Voltage at battery is 12+V. Must be good at starter since it cranks and starts fine.

2 wires coming out the small connector on top of alternator. I believe the alternator is a Delphi - AC Delco 102 amp.

Brand new battery - lug bolts seem ok - hate those Chevy battery lugs.

Could we run a 8 guage wire with 3/8" round spade ends directly from altenator lug to under battery connector? Disconnect current alternator cable and tape up the end. If he gets 14.4V then - does that proves bad cable or ground - correct?

Could we just then isolate the bad cable and remove it - does it originate at the battery terminal or some type of junction block? Will get some prints from Alldata tomorrow.

Will also check for ground issue - seems staight forward enough.

Any other advice?

DTP

[Jeremy airjer W]

If it starts and runs than the ground issue is not likely. I'm thinking that that battery cable to the back of the alternator has some corrosion, dirty, or bad connection issues. I can't specifically remember how the cable is routed on that vehicle. A printout of the charging system from alldata will help with that. I would double check the connections at the battery. If it has the dual positive cable setup check for corrosion inbetween the two cable ends where the connect at the battery.

It should be fairly easy to track down where the power is being lost. One test lead on ground and start probing with the other along wherever that cable goes.

I'll get a printout of that charging system diagram tomorrow at work so we will be on the same page.

Good luck!!

[dtp]

Airjer-

Problem fixed - corrosion at fusible junction block.

[Jeremy airjer W]

Fantastic! I hope you have learned your lesson! post all your problems here before you start forking out the cash!!!

[PierBridge]

Gotta love the Croix great fishery and Free diagnostics to boot...

AWESOME!

[Big Jeff]

DTP are you going to hit the water again this weekend?

[dtp]

Went deer hunting north of Greenbush- shot my management doe- no big bucks running yet. Saw lots of deer - nothing over 6 pt. Wedding to attend this weeekend, plan to fish or slug hunt early a.m.