So I just got the engine swap done in the Brat, YAY! Now I have a new problem. Once I got everything hooked up and double checked everything, I started it up. This is not the alternator that was on the previous engine that blew a front main seal either. So I started the engine up and the alternator light, brake light, parking brake light, and one other (I can't remember) were on. I figured the battery needed to charge. Well I let it run for a few minutes while I did some tuning on it and the lights were still on! I don't have a volt meter with me anymore but I kinda checked it with a test light and it was very bright, like brighter then 12 volt bright. Any thoughts? it drove just fine but I need to fiddle with the mixture screw a bit cause it backfires a little.

Put the other alternator in, see if it still does it.

well its possible the only other alternator I have is covered in oil and I don't really want to see if it still works. I'll check to see if I have a spare but does it sound like the alternator is gone? I'll be getting some voltage readings here in a few.

Check all your grounds. It sounds like voltage is feeding back through your dash lights because it's looking for a ground.

Those dash lights are tied into the alternator exciter circuit and will light up when the alternator has trouble. It sounds like the internal regulator is bad in the alternator. I wouldn't drive it until the alternator is replaced, the excessive voltage output may damage other things.

Those dash lights are tied into the alternator exciter circuit and will light up when the alternator has trouble. It sounds like the internal regulator is bad in the alternator. I wouldn't drive it until the alternator is replaced, the excessive voltage output may damage other things.

well the volt meter in the car is reading less then 12 volts though. I'm still going to check it with a volt meter but its running and driving just fine. Could it be a dirty connection possibly? IIRC, this alternator on this engine was working fine when I had the engine in a '81 wagon.

The dash voltmeter is at a different connection point than the alternator output so the two points can be different in voltage level though they should be the same. Typically there is about a one volt difference in voltage between the battery level and what the meter shows due to wire losses.

 

You stated that the test light was brighter than normal at the point you connected it to. This would indicate more voltage than what is normal. The true test is with a meter probing across the battery posts and the alternator output, which should be very close to the same readings. If you have more than 15 volts out of the alternator then you have a regulator problem. If the dash lights are on, then there is either a problem with the alternator or the wiring to it.

well had the guys at work test it today. Battery was good but the alternator was dead as a doornail. No ripple from the diode no nothing. So I went and replaced it with a different one on my lunch (woo, a whole 5 minutes) and she got a little more peppy and the lights went off. Now the voltage gauge is reading 14 volts so all is good...

My 88 wagon was doing the same thing as my alt went bad so changed it with a used spare and went away...now my used one is now acting up so yea.. I believe it is just a strange thing these do when the alt is tweeking out.

 

 

Also; don't forget to post that problem is "FIXED" as this is a good bit of info for Noob's to know about.