Battery not charging while driving

[nickmpower]

We just got our Ultima on the road yesterday and all seems well except the battery doesnt charge. At one point it got down to around 9 volts. the turn signals were slow and the tach was funny. We switched the 6" pulley for a 3" pulley and the same thing happends. There is pretty much no resistance between the battery cable and the alternator post. The Alternator is a new one supplied with our american speed engine.

also one of the times I shut it off yesterday and gave it a quick stab at the gas while cutting the ignition and the engine dieseled around once. Is this something to be concerned about?

[GreenV8S]

It's possible the alternator is faulty, but check that it's wired up correctly. I'd expect to find a switched ignition feed to energize it, a voltage sensing wire from the battery and the main output (high current) wire to the battery.

[Builder]

GreenV8S said:

It's possible the alternator is faulty, but check that it's wired up correctly. I'd expect to find a switched ignition feed to energize it, a voltage sensing wire from the battery and the main output (high current) wire to the battery.

Yes, also check that the ignition switch is wired properly and functioning. It can cause the energizer circuit to fail.

Regarding the engine dieseling, unless there's a valid reason to the contrary, I wouldn't give it any gas before turning off the engine. All that does is dump fuel into the combustion chamber while killing the spark (if I understand what you did). The fuel is burning from engine heat. Also, what type of fuel did you put in?

[nickmpower]

here is how it is wired

[GreenV8S]

I have no idea what those wires are or whether it's correct, but a live wire pressed against the casting like that is simply asking for problems a few years down the line.

[nickmpower]

I just did some poking around with the voltmeter and it seems like the alternator case is not grounded, or not very well grounded. I take it this is probably our problem? seems like the AS powder coated bracket wont let the case ground. What gauge wire should I use for a separate ground wire?

Edited by nickmpower on Sunday 9th September 00:54

[nickmpower]

I made a ground for it and now it stays pegged at 14v

[GreenV8S]

Maximum current 100A or so for a typical alternator.

[Steve_D]

nickmpower said:

I made a ground for it and now it stays pegged at 14v

That may work for now but the wire gauge would need to be really fat to give the full charge current when required.
Better route is to clear the powder coat both at the alternator and where the bracket joins the engine.

Steve

[nickmpower]

i dont think its any smaller then the factorys way too small wiring