Alternator Wiring after Previous Owner Conversion

[Qaf]

Does the P/S alternator need to be grounded to the engine? D/S alternator has been removed after conversion. Everything worked as it should electrically. I had to replace cracked heads (bought it like this, unbeknownst to me). Neighbour & I did it. Afterwards, started & drove. Noticed battery wasn't charging & vehicle died on me after couple of days driving. Looked at alt & noticed the bottom post on alt had black wire that neighbour connected to the positive side post on alt along with 3 other red wires. I'm fairly confident that's incorrect. Doesn't it need to be grounded? What damage has been done if so? Alt Diodes? Battery is new. No instrument panel lights work anymore (4x4, idiot light, oil pressure light, etc). Checked ohms on all the fuses underneath driver side & they all checked out.

 

[MarcusOReallyus]

That doesn't sound right, but it's always hard to second-guess someone else's hack job. Some pics would help.

Can't hurt to disconnect it and tape it off and see what happens. If it's a stock Chevy alternator it should ground through the case, but if it's a CUCV alternator it's isolated ground so yes, that ground wire should be grounded.

But I would not be surprised if the thing is deader than a door nail from being wired incorrectly. Blown diodes and the like. You might need to rebuild it. Member Tow4 has rebuild kits, and can answer any questions you might have about rebuilding. It's not a difficult job.

I think most of us here would recommend putting it back in stock 24v configuration. That way the TMs and the folks on this forum can help you when you have problems. With some unknown person's unknown hack job, it's pretty difficult to give troubleshooting help.

Another thing to consider - your stock battery wiring was sized for 24v. When you have only 12v to turn over the same engine, you need twice the amperage. Volts X Amps = Power. So, since you need the same power to turn the engine, you need twice the amps since you have half the volts.

That means your starter will always be starved for voltage and it won't turn over as fast. That ain't good.

So, if you decide to keep it 12v, consider replacing all of your battery cables.

 

[Qaf]

That doesn't sound right, but it's always hard to second-guess someone else's hack job. Some pics would help.

Can't hurt to disconnect it and tape it off and see what happens. If it's a stock Chevy alternator it should ground through the case, but if it's a CUCV alternator it's isolated ground so yes, that ground wire should be grounded.

But I would not be surprised if the thing is deader than a door nail from being wired incorrectly. Blown diodes and the like. You might need to rebuild it. Member Tow4 has rebuild kits, and can answer any questions you might have about rebuilding. It's not a difficult job.

I think most of us here would recommend putting it back in stock 24v configuration. That way the TMs and the folks on this forum can help you when you have problems. With some unknown person's unknown hack job, it's pretty difficult to give troubleshooting help.

Another thing to consider - your stock battery wiring was sized for 24v. When you have only 12v to turn over the same engine, you need twice the amperage. Volts X Amps = Power. So, since you need the same power to turn the engine, you need twice the amps since you have half the volts.

That means your starter will always be starved for voltage and it won't turn over as fast. That ain't good.

So, if you decide to keep it 12v, consider replacing all of your battery cables.

appreciate the response. I slapped in a bulldozer battery with 1450 CCAs so the amperage shouldb’t be an issue. It’s the stock CUCV alternator. I’ll ground it out to engine & let you know what happens. I agreewith the hack jobhate going in after someone already messed up a beautiful thing

 

[Qaf]

appreciate the response. I slapped in a bulldozer battery with 1450 CCAs so the amperage shouldb’t be an issue. It’s the stock CUCV alternator. I’ll ground it out to engine & let you know what happens. I agreewith the hack jobhate going in after someone already messed up a beautiful thing

Posted pictures now. The one with the front of engine was before I went to replace the heads. You can see

That doesn't sound right, but it's always hard to second-guess someone else's hack job. Some pics would help.

Can't hurt to disconnect it and tape it off and see what happens. If it's a stock Chevy alternator it should ground through the case, but if it's a CUCV alternator it's isolated ground so yes, that ground wire should be grounded.

But I would not be surprised if the thing is deader than a door nail from being wired incorrectly. Blown diodes and the like. You might need to rebuild it. Member Tow4 has rebuild kits, and can answer any questions you might have about rebuilding. It's not a difficult job.

I think most of us here would recommend putting it back in stock 24v configuration. That way the TMs and the folks on this forum can help you when you have problems. With some unknown person's unknown hack job, it's pretty difficult to give troubleshooting help.

Another thing to consider - your stock battery wiring was sized for 24v. When you have only 12v to turn over the same engine, you need twice the amperage. Volts X Amps = Power. So, since you need the same power to turn the engine, you need twice the amps since you have half the volts.

That means your starter will always be starved for voltage and it won't turn over as fast. That ain't good.

So, if you decide to keep it 12v, consider replacing all of your battery cables.

Posting photo of P/S alt. Haven't hooked the battery up yet. Bottom left post (which I'm assuming is supposed to be grounded to engine) has that black wire that was initially hooked up with the 3 red wires on the post next to the 2-wire harness. I rerouted that black wire to the engine. Safe to hook up battery?

 

[MarcusOReallyus]

I slapped in a bulldozer battery with 1450 CCAs so the amperage shouldb’t be an issue.

You could put 10 of those in parallel and it wouldn't help. It's still got to go through those skinny wires, so that big battery may last forever while you are cranking, but it's not going to turn that motor over any faster than a battery with half the CCA. Ohm's Law says nope.

The only way to get more amperage to that starter motor is to increase the voltage OR use bigger cables. The CCA of the battery doesn't matter.

But you have more to worry about right now, like getting it charging. Once you have it running you can take some time and think about where to go from there.


EDITED to correct my statement about getting more amps to the starter motor.