Charging problems

[walterd140]

OK. Wifes 94 Pontiac Trans sport mini van had a dead battery. So I got a new battery which also died. Went & got a new alternator (140 amp instead of her 120 amp). Issue fixed for a while. Then all dead again. Was told it was a fusable link, so I found those & fixed them. Then all is good until about a week & died again. Off to see my brother & his multimeter. Check show battery is charged / accepting & alternator running at 14 volts. So I believe the gage is bad. Bro says to clean the terminals which worked wonders for the gage. So I tell the wife as long as the ABS & Airbag lights don't come on then it's fine. Well last night she says the lights came on & headlights were very dim. Van crawled into the driveway where it sits now. I am at a loss.

Battery is accepting charge, gets 13 - 14 volts with car running
Alternator puts out steady 14 volts
No continuity between disconnected pos & Neg wires, so harness is OK.

Was wondering if the higher amps from the alt were shorting out a fuse. If so How would I find / verify this?

Should I / do I need to check the starter? Why would this be an issue?

Thanks for the help, I'll be out in the driveway staring at the engine until you get back to me
Walter

 

[JDraper]

Check all the body grounds on the vehicle. I had an issue like that with an old Monte Carlo. The ground straps from the motor to the vehicle were rotted off and I wasn't getting good grounding back to the body. Also make sure the battery cables are well connected on the ends away from the battery.


The higher amp alternator "shouldn't" cause any problems, and the only way the starter might be an issue is if it's shorted out.

 

[walterd140]

Thanks JDraper. When you say the ground strap, you gave me an idea. I checked the negative battery cable to the block (good clean connection btw), but never looked for a block ground strap to the frame. I'll put down my java & go check that out.

 

[shamaal]

If the battery cable terminals are still the crimp type, be very suspicious. They corrode internally and become a high resistance connection. If applicable, change to the clamp on style that you can see the wires.

Also, if you can twist the connector on the battery terminal, it's too loose. Sometimes the post cleaners remove too much of the post for the cable connector to tighten adequately. When this happens, hammer the removed terminal so it's slightly out of round, reattach, and it will tighten right up.

 

[walterd140]

Thanks for the input shaamal.

Posts are the side bolt screw ins. Check for continuity between battery & block (the cable) & it was clean. Checked pos battery to alternater continuity & clean also, so I do not beleive it to be a corroded cable.

Also to JD's point I could not find a block / frame strap, but checked continuity between block & a bolt for the radiator. Checked ok (not pure clean) but figure that's good enough concidering I used a rusty / painted bolt.

Seems to be a time issue. I drove the van all day yesterday in short trips & gage never dropped below 14 volts. But when it died the wife was on a 2 hour treck across the malls of america . So the length of the time the van is on just keeps ticking in my mind. Longer drive will cause the issue. Maybe I either have a melting fuse or cable & it needs to 'cool down' a bit. But as of now, as I told wife, I cannot find anything to fix because it all works better then my truck with no issues.