Repetitive alternator replacement

9
1
3
Buick Ownership
96roadmaster
Thread starter #1
I inherited a 96 roadmaster with the 350 lt1. It burns out alts on a regular basis. I have recently gone to a 170 amp , but it died after only a few days. They all stop charging. New batteries, twice , no extra electrical devices. Just point and i will chase.
 

HotZ28

Full Member
6,307
72
48
Buick Ownership
1996 Roadmaster Limited Collectors Edition 58k - 1996 PAU
#2
I also have a 96 RMS Limited Edition with the original CS144, which has never given a problem. I keep all battery terminals clean, and replace the battery every few years, even if I don't have any symptoms of battery failure. Where are you buying these alternators from? I hope they have a warranty! You could have a ground, PCM, or positive wiring issue. Check all connections from the alternator to the battery and see what you discover. I wish I could offer more advice, but you need to do some testing and keep us informed of the findings!
 
Last edited:
9
1
3
Buick Ownership
96roadmaster
Thread starter #3
I had warranty but, chasing the origin is the trouble. Three different sources of parts. I am currently looking at the control wireing the two wire connector. I dont have the haynes book yet, but its coming. What signal or what voltage is it looking for, ohms of resistance?
Also, where is the voltage regulator located? I have found a part but not any other info.
 
9
1
3
Buick Ownership
96roadmaster
Thread starter #4
I had warranty but, chasing the origin is the trouble. Three different sources of parts. I am currently looking at the control wireing the two wire connector. I dont have the haynes book yet, but its coming. What signal or what voltage is it looking for, ohms of resistance?
Also, where is the voltage regulator located? I have found a part but not any other info.
It comes up an external part?
______________________________
 
9
1
3
Buick Ownership
96roadmaster
Thread starter #5
It comes up an external part?
It comes up an external part?
It comes up an external part?
Ok, pulled the alt, tested, diode failure chased wire back to harness junctions, FOUND insulation off and the two brown twisted into the yellow "also bare" and brown AC wires. Wires are not burned, but kinked. It appears that tugging an extra inch may have caused this. Tape and replace. See what happens.
 
9
1
3
Buick Ownership
96roadmaster
Thread starter #6
Ok, pulled the alt, tested, diode failure chased wire back to harness junctions, FOUND insulation off and the two brown twisted into the yellow "also bare" and brown AC wires. Wires are not burned, but kinked. It appears that tugging an extra inch may have caused this. Tape and replace. See what happens.
Drove straight to parts store, to test the alt, smoke, from the paint when i opened the hood. Alt smoked the regulator . Still 13.5 volts
Any ideas
 
9
1
3
Buick Ownership
96roadmaster
Thread starter #7
Drove straight to parts store, to test the alt, smoke, from the paint when i opened the hood. Alt smoked the regulator . Still 13.5 volts
Any ideas
Can I just get a one wire alt, and be done?
I will trace back to source on the wireing. And hope to get lucky. I have checked all fuses. They are good.
Speculation is encouraged
 

HotZ28

Full Member
6,307
72
48
Buick Ownership
1996 Roadmaster Limited Collectors Edition 58k - 1996 PAU
#8
I don't think a one wire alternator would allow the PCM to monitor the battery voltage and excite the regulator when required. If I were you, I would continue searching the wiring for flaws.
______________________________
 
9
1
3
Buick Ownership
96roadmaster
Thread starter #10
Found alt brn with fuse removed, fuse 17 20 amp removed, brn/ white wire goes to f5 which is unused. Today i received my one wire alt, inspection shows it to have the alt pinout in place to hook up the harness..
To be continued
 
9
1
3
Buick Ownership
96roadmaster
Thread starter #11
Found alt brn with fuse removed, fuse 17 20 amp removed, brn/ white wire goes to f5 which is unused. Today i received my one wire alt, inspection shows it to have the alt pinout in place to hook up the harness..
To be continued
Yay, done. The final issue was fuse 17 missing. ?
Repaired strettched and cut insulation wire to alt at harness. Repaired P.S. pump cut insulation, and AC pressure sw wire insulation. Separated wires and rewound wrap. Car runs fine, and tests fine at parts store
 
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