I was hoping someone could help me with my 3g alternator on my 90 GT. Going by my stock gauge, the battery is at about 14 volts (stock gauge halfway) with my A/C and radio on at idle. Once I turn on my headlights it drops to the last mark right before the 8 volts. I was wanting to add an electric fan so I need to get this problem fixed. Now I've read many posts and I have my alternator wired just as they have mentioned. I connected a secondary 4 gauge ground going from the chassis battery pigtail ground to the block connected in the same spot as the main ground on the power steering pump bracket. That didn't help so I moved it to a spot on the A/C compressor bracket and still no better. What do you think is the problem and what to you suggest I do?
3g alternator
- Thread starter twinsnakes23
- Start date
Use a DMM to test the system voltage at the battery. The stock gauge is all but useless, and certainly useless for diagnostics.
If the system voltage is good with no load but drops below 13.0V at idle with some accessories on, take the alt in for a bench test. It might have dropped a diode.
Good luck.
If the system voltage is good with no load but drops below 13.0V at idle with some accessories on, take the alt in for a bench test. It might have dropped a diode.
Good luck.
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