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tchudy tchudy is offline
Nigel Tufnel Wannabe
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Join Date: Sep 2011
Location: Channahon, Il
Posts: 207
Alternator charging issues & blue exciter wire

Wondering if one of you can help with my alternator issue. The last couple years my alternator had no voltage at start-up, but if I revved the engine a few times the voltage came up to about 13.9. A few weeks ago I had no voltage even if I revved the engine. The alternator tested okay at autozone but I decided to replace the alternator wiring and add a Nissan alternator. I modified and wired the new alternator same as the diagram and instructions from Rennlist forums. I have 12.5 volts at the battery, the starter and the alternator with the key off. I have just under 12 volts with the car running at the battery. Revving the engine makes no difference.

After reviewing many forum posts I pulled the cluster and removed the "battery light" bulb. Bench tested and it is okay. I added a ground to the alternator body and it made no difference. My alarm system has not had the module attached for many years and it is not jumpered. The old alternator had worked okay the last few years so I doubt that the alarm is the issue. I went ahead and jumpered it anyway and no charge. Assuming the new alternator is good (I'll take it out and test if needed), what is the next step? I was thinking of sending a few volts down the exciter wire where it connects at the power brake booster. Thanks
1986 Porsche 944 Turbo Project.
2005 VW Jetta GLS
2000 Toyota Solara...boring to drive but good mileage.
1971 VW Super Beetle...sold it to make room for the Porsche.
Old 12-04-2017, 08:05 AM
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