why does my voltmeter do this??
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TECH Addict
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Joined: Apr 2005
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From: Northern Kentucky
why does my voltmeter do this?? well I have had her tuned and put headers and full exhaust along with ported throttlebody and taylor spark plug wires 10.5mm, and whenever im driving at night and have my headlights or foglights on the damn voltmeter goes down to the 13 and sometimes lower. when im driving its up around 15 or so volts and then once i come to a stop the damn thing goes down like its runnin outta juice, car doesnt feel like its gonna die or anything it just pisses me off and want to know why it does this, i also have one JL audio 10 with a 200 watt amp. think i should get my underdrive pulley here soon along with a overdrive alternator pulley and that will fix my problems???
With the stock pullies, the system should charge just fine. Mine would do that once I installed the crank underdrive pulley. I ened up raising the idle to 700 rpm and the issue was resolved. At the time, I was running a 600W MTX Amp very slight dimming at night. Might want to get have the alternator checked out. The alternator output might be getting low or the regulator might have an issue.
Diddo the alternator regulator may have an issue most likely, The voltage typically in most cars will move up in down lower at a stand still higher going down the road. 13 volts is alright 15 is pretty good. Get the alternator tested and have all accessories on when you do it, window wipers, radio, heat or a/c, lights. If the alternator is tested and it turns out that its ok check the pulleys.
TECH Senior Member
Joined: Apr 2004
Posts: 6,157
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From: Texas
Sounds more tuning related then an altenator problem.
Does your RPMs fluctuate when you come to a stop?
Also, the stock volt gauge is not that accurate (I highly doubt your charging 15 volts while driving)
Does your RPMs fluctuate when you come to a stop?
Also, the stock volt gauge is not that accurate (I highly doubt your charging 15 volts while driving)
