Serious voltage drops

[DiabolicCustoms 4]

Here's what i have

Excessive Amperage 180 amp alt. 110 at idle

big three plus more doen in 1/0 ga

optima yellow

19 feet 1/0 ga to the trunk

5 inches of 1/0 from amp to ground

MTX thunder elite 1501d

during testing yesterday i found that on the voltmeter mounted in the dash (aftermarket) it would drop down to 12.3 and lower during a romp on the new xcon.

i haven't tested at the amp yet but shouldn't the volt meter be a good indication of the drop in the rear?

the alt tested out good the last time we had it benchtested by excessive.

any clues or ideas?

[DrgUpsy 0]

I would think you have a bad battery. Could be wrong but i have seen this happen a few times

[DiabolicCustoms 4]

its never failed to start or even hold a charge, never had to jump it. or do you think that under serious load it could be failing but still decent enough to run the car.

[jcarter1885 995]

What kind of volt meter do you have, if it is a Stinger did you calibrate it before using it? If not then ignore my post.

[shizzzon 461]

sorry to say this but look at it from this perspective-

That 1500w amp on music should rarely be pulling above 100A and if it does, it's very fast and that's it.

your alternator is capable of outputting 110A at idle (supposedly) so for u to be dropping that low means your alternator rating while driving is a lie...

Second, if u were to tell me that you had a STOCK alt and a single yellow top in there, dropping that low may be normal...

However u have a H.O. (supposedly)

Get your dmm out and check to make sure the voltmeter isn't wrong first.

If it's not wrong, jam on it for a while then turn it off and measure voltage at alternator, then front battery, then at amp.

This allows the wire to heat up to get better voltage drop measurements, if there are any, to see if u have any problem areas.

[DiabolicCustoms 4]

Thanks, I have the printout from the bench test. Nathan Perricord has never doen me wrong on any of the high output alts i have purchased from him. I guess its time to do some snooping around with the dmm. thanks for all the help. i wish it was a easy answer, like yeah you have your turn signals drawing all the power away from the amp or something. lol.