72 Cutlass GEN light illuminates
#1
72 Cutlass GEN light illuminates
1972 Cutlass Supreme. When I shut off the car the GEN light illuminates and stays lit. It is not on when the car is running. I had this issue before and had the alternator serviced and that helped for a while. Also when I had the issue before I could unclip the plug on the alternator and the lamp would go out. When I try that now, the lamp stays lit. Only way to extinguish is to pull the cable off the battery terminal.
Any suggestions before I take it back up to the alternator shop?
Thanks in advance
Any suggestions before I take it back up to the alternator shop?
Thanks in advance
#3
A bad diode in the alternator will definitely cause this, but he said when he unplugged the alternator connector the light stayed on. If it were a diode, unplugging the alternator would break the circuit and the light would go off.
I have no idea what would cause this issue.
I have no idea what would cause this issue.
#7
Hi Fun71! The thick red wire that goes to the back of the alternator goes to a rectifier bridge that also has diodes in it. But yes, it was late last night, holy stuck contacts Batman! Voltage regulator can be bad as well, is it the mechanical type on the firewall? How easy one forgets in the day and age of electronics.
#9
I'm thinking it was a grounding issue. The battery terminal may not have been making good contact with the threaded post. I put in a longer threaded post and its making much better contact and now my GEN light isnt coming on with the car off. Coincidence - maybe, but for now, issue resolved.
Thanks for all the suggestions.
Dean
Thanks for all the suggestions.
Dean
#11
I am battling the same issue right now on my 72 Supreme. The only way the light will go out is to disconnect the voltage regulator harness or disconnect the battery. I had purchased a new regulator last year and this issue just started up when I got the car out this past week from storage.
Regulator Replacement?
Regulator Replacement?
#12
I feel your pain. Replaced the Regulator. Rebuilt the alternator. Replaced battery and battery cables. Same results. I'm convinced there is a short elsewhere in my vehicle, but not in the know of how to diagnose and find it.
I resolved by adding a battery cut out switch (for about $20) and I flip the switch at the end of the night and when I put he car back in storage. It wont "fix" the issue, but its a manageable solution.
I resolved by adding a battery cut out switch (for about $20) and I flip the switch at the end of the night and when I put he car back in storage. It wont "fix" the issue, but its a manageable solution.
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