What a day yesterday was!! I load tested the alternator using the grid heaters. It seemed to really kill the alternator output. So I took the alternator to a rebuild shop I’ve used for 25 years, and they tested it on their fixture. At full field current it showed 22 volts and 120+ amps and climbing! Almost no ripple in the waveform either!! I was happy!! But then why were the grid heaters bogging it down so badly?? One other pain was that there was a squealing sound under the hood. I could not tell if it was the alternator or either of the idler pulleys. I had also taken the alternator to Kragen to have it tested. Their tester is lame. But the parts gal heard clearly that there was bearing noise. I heard it maybe one time. She looked at me like I was deaf. So with the alternator already out I tore it completely apart and put in new bearings. The pics of the alternator rebuild will be in another post. The new bearings did in fact take out the squealing completely!!!

I connected a dvm from the alternator output bolt to the positive battery terminal. It read .6v when one grid relay was powered. .6v x 80a = 48 watts of lost power. Also the large 6 ga wire over on the fender well has a large bullet connector on it that gets warm. That means it’s not doing it’s job perfectly. I took it apart and it was oxidized inside. Sometime I’ll either cut that connector out or try and clean it.

So after the alternator rebuild I went after the grid relays. Before the alternator was removed, I had turned the ignition on but left the engine off. Then I used jumpers to activate the grid relays manually. Each relay was sticking!!! Sometimes both of them would stick in the on position for 10 to 20 seconds at the same time!! Time for a tear down!! The tear down pics will also be in another post. I found the problem in each relay that caused the sticking. Once it was fixed, they would come on for 10 seconds then off. Then on again for 5 seconds. Then off. This was all pcm controlled. I tried to feel each relay to see if they were coming on at the same time. I don’t think they were! I think they were alternating. But the temperature warmed up and they stopped engaging before I could figure it out for sure. So I’ll do that tomorrow morning!!