1988 7.3 BATTERY LIGHT ON AFTER NEW ALTERNATOR??

NOAH MATTEOLI

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It is fixed. new alternator....but problem was all of the fusible links for glow plugs and ignitin were hooked to the positive side of solenoid lol!! Nothing was grounded.
 

Macrobb

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It is fixed. new alternator....but problem was all of the fusible links for glow plugs and ignitin were hooked to the positive side of solenoid lol!! Nothing was grounded.
Uh...?
The fusible links for the glow plugs and ignition should connect to the positive(battery) side of the fender starter relay - so it gets power at all times.

They just use that bolt from the factory as a connection point for all the 'accessory' wires.
 

franklin2

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At 13.2 you are charging. I noticed my older style alternator charges at a lower voltage, usually around 13.5-14v depending on the rpm. If you raise your rpm some, the voltage will probably go up a little bit.

My 89 has a factory volt gauge, and after starting the truck the volt gauge will be to the left a little bit. Once it runs awhile and the alternator gets the batteries charged back up, the voltage gauge will be straight up in the center of the scale.

A 3G would probably charge at a higher voltage/rpm, that's what they are noted for. As far as the 130amp output on some of the 3G's, you really can't use that with a single v-belt, the single belt doesn't have enough traction to give the full output. Not a problem except if the batteries call for it, the belt will squeal sometimes.
 

Macrobb

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At 13.2 you are charging. I noticed my older style alternator charges at a lower voltage, usually around 13.5-14v depending on the rpm. If you raise your rpm some, the voltage will probably go up a little bit.
Working right, you should see something like 13.x at idle, but by 1,000 RPM(while warm and charged), you should be in the 14.0-14.5 range.
If above that, something's wrong(probably regulator). If below that check the wiring.
 

NOAH MATTEOLI

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I bought a ground strap from the engine block to the cab. I only have low voltage heater and wipers.... headlights can be on and not cause any draw. when I turn on heater motor it causes a draw. It has to be cab grounding.
 

NOAH MATTEOLI

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Uh...?
The fusible links for the glow plugs and ignition should connect to the positive(battery) side of the fender starter relay - so it gets power at all times.

They just use that bolt from the factory as a connection point for all the 'accessory' wires.
 

NOAH MATTEOLI

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Nothing was grounded though...I guess you misunderstood me. Both of those posts are hot. only the right one is hot when you crank the engine. They had burned ground wires... because they hooked a negative to one of the solenoid posts.
 

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