Best replacement alternator?

[dn010]

I decided to revisit this yesterday after getting frustrated with voltage drops to 10 at idle even if it's just trying to power only the vent air motor on 1. I removed my air filter and filter shield (EFI setup) and found this which made me glad I checked.

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Regardless of this, I removed the alternator and disassembled it. The rear bearing is trashed. Maybe half of each brush was making contact with the rotor and the brush carrier was a little cracked and melted on the bottom. The alternator is done. I will be pulling my second alternator from my '57 Cadillac (originally a Hervey alternator I used to swap out the generator) to use for now until I can gather $200 for a new alternator.

[Chris 16409]

You can give this a try:

https://www.ebay.com/itm/140740542668

It's been tested to work in a friend's car. Just swap the pulley with the v-belt one on your old alternator.

[dn010]

Thanks for the link. I was about to click buy it now, until...

I recalled have two Volvo 780 Bertone alternators. Didn't have a clue if it would fit or not but after a forum search it seemed there was a good chance. So, I grabbed one of them and started to compare it to the old alt and it looked good. I installed it. It bolted right up to the original mount without a spacer. I will have to figure out a bracket, I have a few different ones so I'm sure I have the original somewhere. Wired up the two battery wires to the main connection bolt, and then crimped a connector to fit the blade fitting sense connection. Started the engine. No charge. I checked the connections and did it again but still got no charge until I got some RPMs on it to excite, now it is charging beautifully! My gauge is not at all accurate but readings from the battery look pretty good to me. I can have everything possible on and get over 13V although the gauge doesn't show it. I can have my lights on and they won't dim at idle - I'm not really sure how to take this, it will be a while to get used to having a good charging system...

Some photos:

Comparing the old Hervey alt to the Volvo 780 Bertone one:

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Some shots of it

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Installed, without adjusting bracket at this time:

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Everything on at full tilt and a shot of the inaccurate gauge:

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Everything off:

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Everything possible on @ idle:

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Everything possible on at 2000 RPM:

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I'm off to either find or make a bracket so that I can bring my son to his last day of 4th grade tomorrow and make his day!

EDIT: I like to add that my fuel injectors (EFI) are really enjoying the reliable power as well!

[Chris 16409]

The DeLorean gauges were never super accurate. As long as the alternator shows it's outputting enough on the multimeter, you may have to accept the lower dash reading. Part of the problem may lie in all the common grounds that join up at the instrument cluster. After discussing things with Dave M in the past, he believes you can get a higher dash volt reading if the fule pump is given a dedicated ground. Normally the pump is grounded along with the other instruments. I've relocated my fuel pump ground to the shift plate, and noticed a difference.