Electrical Probs

[Numba1sean]

anything and everything. lights dimming, when i hit the gas the rpms go up and when they come down the voltage drops bad, and the blinker is making the gauge move. battery terminals are really tight and i have a red top and a brand new alternator. but the battery stays at 12.1 when off and someone told me thats a little low. my gauge also does not stay above 14. so im not sure what else can be wrong. big 3 is done in 1/0, high output alternator, and optima redtop. just seeing if you guys have any ideas. the rpms thing is with no system on at all, so thats why im confused. not to mention this is my fourth alternator, cuz i thought they were all bad and now im thinking not.

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[NoPh33rRaCiNg 10+ year member]

i didnt know what to tell him, he has a smaller pulley also guys...

 

[Numba1sean]

hah you are here too. yea any help, driving me crazy right now. thought i would ask around before i pay someone to look at it for me.

 

[jrwalte 10+ year member]

Having the low voltage at idle is due to the HO alt not spinning fast enough to start the electrical field and it's giving absolutely no output. You may have a smaller pulley, but not small enough. The low bat voltage is probably due to idling too often with a load from the stereo and not enough time inbetween to give the battery a good charge.

What RMS are you running? 1 battery may not be enough, either. Having an HO alt does not prevent one from requiring a second battery. It does just about nothing, actually.

 

[Supergumby5000 5,000+ posts]

Having the low voltage at idle is due to the HO alt not spinning fast enough to start the electrical field and it's giving absolutely no output. You may have a smaller pulley, but not small enough. The low bat voltage is probably due to idling too often with a load from the stereo and not enough time inbetween to give the battery a good charge.
What RMS are you running. 1 battery may not be enough, either. Having an HO alt does not prevent one from requiring a second battery. It does just about nothing, actually.

hrm, my HO alternator sits at 14volts cold and 13.5-13.7 warm, mebe i should get a smaller pulley....

 

[jrwalte 10+ year member]

hrm, my HO alternator sits at 14volts cold and 13.5-13.7 warm, mebe i should get a smaller pulley....

Since it's actually giving output (otherwise it would be at the battery voltage), a smaller pulley may not help you. You can test this by rev'ing the enging about 100 RPM higher than idle. If it makes a difference on your voltage, then consider a smaller pulley.

 

[Numba1sean]

well i have the smallest pulley i can get and changed my belt to accompany it too. me reving my engine does not help at all. full day no system on at all and it will still do the same thing so im not sure thats the problem. i was holding 14.4 at the battery with my old battery and since i changed to the optima its been worse. i was told by another that i may have a bad ground somewhere. and my alt does 105 amps at idle. oh yea and not even 600 watts rms is what im running, so its like nothing lol compared to other ppls stuff ya know.

 

[NoPh33rRaCiNg 10+ year member]

well i have the smallest pulley i can get and changed my belt to accompany it too. me reving my engine does not help at all. full day no system on at all and it will still do the same thing so im not sure thats the problem. i was holding 14.4 at the battery with my old battery and since i changed to the optima its been worse. i was told by another that i may have a bad ground somewhere. and my alt does 105 amps at idle. oh yea and not even 600 watts rms is what im running, so its like nothing lol compared to other ppls stuff ya know.

what alt do you have

 

[jrwalte 10+ year member]

Since you've tried multiple alts we can rule that out as the problem. It's something to do with the way you have it connected.

Do you have the regulator harness connected properly? It's not pinched or cut anywhere?

Verify you have a negative run from the engine block to the battery. This can be block to battery or block to chassis and then chassis to battery.

 

[Numba1sean]

harness is connected properly only goes one way. and yes i have that done too, i did the big 3 in 1/0 according to the s10 forum tutorial. and i have minimal resistance on the new grounds that i did. but i have not done a reading on the stock ones.

 

[Numba1sean]

so anymore ideas on this prob??