1 wire Alternator gets super hot!

[j286]

I have a 1970 c10 just recently rewired everything with American autowire 21 circuits harness. I started with a 3 wire 100 amp alternator from Amazon, it was getting extremely hot so I traced out all wiring couldn't find any problems so I assumed I just had a cheap alternator. I replaced it with a 1 wire 100 amp from summit and I'm having the same issue with the new one. Does anyone have any ideas?

[AussieinNC]

The alternator needs a good clean ground path back to the battery,,,,make sure the bracket the alt is bolted to has a clean surface where it meets the alt...plus the bracket to engine and engine to battery and chassis

You cannot have too many ground straps on these trucks....

Engine to chassis
Trans to chassis
Bed to chassis
Cab to chassis
Dash to cab
Radiator support to cab

The ground lead from Negative battery terminal should be direct to the engine, then ground straps engine to chassis and trans to chassis....

Finally, a one wire alternator does not need the voltage regulator...check the woring guide that came with the alternator....

[Red71gmc]

Subscribed

[Duck 37]

Make sure it is grounded well

[AussieinNC]

Hey duck...got ya by a minute...

[j286]

I have a strap from the engine to the frame,battery to frame and from the little ground tab on the alternator to the frame. I also grinded each surface to the metal before installing the grounds.

[AussieinNC]

Add a large ground lead direct battery to engine....

[j286]

I will add a large ground from the battery directly to engine. Thanks for the replies.

[OregonNed]

Originally Posted by j286

I have a strap from the engine to the frame,battery to frame and from the little ground tab on the alternator to the frame. I also grinded each surface to the metal before installing the grounds.

I did the same when I upgraded my alternator.. good grounds throughout

[68is4me]

How hot is hot? 120 degrees to the touch of the hand can seem hot. Do you have any big loads that are making iy charge at max?

[Steeveedee]

Do you have a volt meter or ammeter to check the performance?

[j286]

I added a heavy ground from the battery which I have relocated to underneath the bed floor to a junction block on the frame right beside the motor. Then I added a 4 gauge wire from there to the engine,firewall, and core support. Alternator is still getting hot after idling for less than 5 minutes. Any other ideas?

[j286]

It is putting out 14.38 volts at idle. It has dual electric fans and Dual air compressors for air ride. I currently have the fuse pulled on the air compressor so the electric fans should be the biggest load.no a/c or sound system.