King Lear

I have a couple month old powermaster alternator. I was running the car tonight and noticed a a few sporratic sparks coming off the March alternator bracket ends where it is bolted into the block and the alternator.
I know the engine is grounded and the alternator is wired stock with a 4 gauge wire running straight back to the battery as well. You can see the arm going from the cylinder head to the top of the alternator, that is was is sparking at both ends. Very small sparks, the battery gauge reads fine and battery has plenty of charge. Any ideas?

I was guessing since the alternator housing is grounded with then engine and the arm is mounted with johnny joints and they a greased that the current is jumping accross the joints a little to try and stay grounded.

shafrs3

I see you've got SS braided ignition wires, if that is right are they grounded?

King Lear

Yep, I have a wire running off both sides going to one of the valve cover bolts. Using the multimeter I have continuity between the bolt and the engine ground.

oregonsharkman

Sparks mean there is a potential between the two locations that are sparking. There must be a bad connection somewhere. Go throught and check all your connections.


I know that my answer is a litle vague, but there is a voltage difference between the 2 location that are sparking. For instance if you connected a wire between the sparking areas, it would equalize the potential. There must be a bad connection in the local area.

noonie

Have you got the stock ground wire on the alternator casing?

SIXFOOTER

you need the alternator case grounded thru a wire, those heim joints and chrome brackets will suck as a ground path.

King Lear

Yep, stock wires with the additional 4 gauge power wire running back to the pos battery terminal.
I just thought about the ignition wires ground on the VC bolt, the rtv on the valve cover bolt may have prevented them from properly grounding the plug wire shielding. I just diconnected that ground wire and a ran a direct ground wire from the plug wires to the frame ground. It is too late for me to start it up now to see if that was it, but I guess I will know tomorrow.
Thanks for the input guys,
Rich

King Lear

Thats a good point too, if the other fix doesn't work I will run a direct ground wire to the case and see if that solves it. That makes more sense, it will spark at the engine side then a second later on the other, never both side at once, that is what got me thinking it was joints since they never really tighten down as one solid piece.

noonie

There should be a black ground wire attached to the case of the alternator where the wire loom bracket is bolted. This goes into the harness and also bolts to the front of the core support on the drivers' side. You can see it with the hood open. It is attached there with a sheet metal screw and usually is a bad connection. I usually redo that. I also run an additional ground from the same place on the alternator down to the frame directly below. It never hurts to have extra grounds.

King Lear

All you guys were right, I ran the test light on the case to the ground and it was variable, so I put a ground wire on alt case and it was reading good after that, the alt bracket was not grounding the alt case.

Big2Bird

Bingo

King Lear

That was it, just had it running and no more spark,
Thanks too all that helped,
Rich