Alternator/charging problems
Thread Starter
Pro
Joined: Sep 2004
Posts: 500
Likes: 1
From: Philadelphia PA
Solved: Alternator/charging problems
I'm stumped, if anyone has a diagnosis suggestion.
I rebuilt and tried 2 alternators. Neither are charging the battery enough. Battery meter stays mostly on the - side.
Any suggestions? Thanks
I rebuilt and tried 2 alternators. Neither are charging the battery enough. Battery meter stays mostly on the - side.
Any suggestions? Thanks
Racer
Joined: Feb 2004
Posts: 265
Likes: 1
From: Irwindale Ca
Did you add any aftermarket electronics. I added two electric radiator fans. They were making my 62 amp alt strain and the vehicle wouldnt start at times when i was in traffic for a while and stopped the vehicle.
I recently posted that a 1986vette alt 105 amps drops into a 76 vette. Depends what year you have. Ive had no problems and a great charge with all the electronics on. You would need to change the pulley and get a adapter plug for it. good luck
I recently posted that a 1986vette alt 105 amps drops into a 76 vette. Depends what year you have. Ive had no problems and a great charge with all the electronics on. You would need to change the pulley and get a adapter plug for it. good luck
C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
Likes: 2
From: Twin Cities Minnesota
Check the voltage at the two little terminals on the alt.
1 should be 12v the other smallerwire should be about 6 volts, i.e. not zero and not 12.
If it's 12 you have a broken wire, if zero, maybe a bad alt...
1 should be 12v the other smallerwire should be about 6 volts, i.e. not zero and not 12.
If it's 12 you have a broken wire, if zero, maybe a bad alt...
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
Are you sure? For a 4 wire, internally regulated alternator, I thought:
The sensor wire should have full 12V all the time.
The excitation wire should have 12V if key is on.
The car should not be running when you test this.
The sensor wire should have full 12V all the time.
The excitation wire should have 12V if key is on.
The car should not be running when you test this.
Originally Posted by 427V8
Check the voltage at the two little terminals on the alt.
1 should be 12v the other smallerwire should be about 6 volts, i.e. not zero and not 12.
If it's 12 you have a broken wire, if zero, maybe a bad alt...
1 should be 12v the other smallerwire should be about 6 volts, i.e. not zero and not 12.
If it's 12 you have a broken wire, if zero, maybe a bad alt...
C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
Likes: 2
From: Twin Cities Minnesota
Well running is when things are important, Who cares what happens when it's not IMHO.
The sense wire is a resistor wire so it should not have full battery voltage ( otherwise it would be a very bad resistor )
The sense wire is a resistor wire so it should not have full battery voltage ( otherwise it would be a very bad resistor )
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
I've never wired an alternator with any resitor in the sensor wire.
Are you sure? Are you thinking of the ballast resitor to the coil?
BTW, It always takes me a while to read your posts because I spend a couple minutes looking at your avitar
Are you sure? Are you thinking of the ballast resitor to the coil?
BTW, It always takes me a while to read your posts because I spend a couple minutes looking at your avitar
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C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
Likes: 2
From: Twin Cities Minnesota
Yep I'm sure ( well as sure as I ever am)
Cars with idiot lights use the resistance of the light, those without the light use a resistor wire. That little brown wire has a few ohms of resistance, really!
Thanks! She's not the Wife, unfortuneatly, she was one of the contestants for Ms Car Craft 2005. A eal cutie! I suppose I should put the full size pics on my web page if I was nice :-)
Cars with idiot lights use the resistance of the light, those without the light use a resistor wire. That little brown wire has a few ohms of resistance, really!
Thanks! She's not the Wife, unfortuneatly, she was one of the contestants for Ms Car Craft 2005. A eal cutie! I suppose I should put the full size pics on my web page if I was nice :-)
Thread Starter
Pro
Joined: Sep 2004
Posts: 500
Likes: 1
From: Philadelphia PA
Solved: Alternator/charging problems
Thanks to all for their suggestions. I tested some wires and so on with an amp meter/continuity meter, and found that 2-prong plug to the alternator was bad.
Part change: $3.50
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Part change: $3.50
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