For a few weeks my car has showed low voltage. I bought a new alternator and new battery and it didn't fix it. While cruising its barely over the 13 mark. If i turn a/c on it drops to 13 and if I'm sitting around in traffic it will drop below 13, it won't pick up if I rev it but it will when I'm cruising on highway. Can someone give me some more ideas to check out. Since it started doing this I can tell a loss of power. Please help I love my car but its realy getting on my nerves.

 

TTT for this guy i have the same prob.

 

Hey there... how are you measuring the voltage? I have the AutoXray 6000. Top model. yet it consistently reads one volt lower than the voltage at the battery.

I tested with a digital Volt Meter and AutoXray at the same time. When I Emailed the AutoXray support they replied with "it just reads what the PCM is telling it and that my voltage maybe low at the PCM". So I checked the Voltage at the PCM and it was exactly the same as the Battery.

I took My Digital Multimeter and measured some of the Voltage regulators I have at home and my 12 volt power supply. The measurements were perfect. My car runs fine otherwise.


Just a note to let you know there is something fishy with the way my AutoXray is reporting voltage.


Marvin

 

I'm measuring the volts by my guage. I think its accurate because when the problem started my volts was dropping way down and lights would get real dim, thats why I think theres a problem. Then a few days later it stopped doing that, but it hasn't been the same since. I left my stereo on for about two hours while cleaning my car is when this started. I had the key turned to accerories. You don't think I could of burnt up a wire or something do you? I'm all out of ideas. Please help.

 

Im thinking ive burnt a wire or something to. I can not for the life of me figure mine out. Im still tinkering tommorow im gonna sand the lil red wire end and where it hits the alt. i hope that works. if we did fry a wire how do we fix it?

 

hey dude just take all your battery terminals off andthe red and black grounds too and the ones on the front by the radiator deal, take all them off and wipe the corrosion off and it will be back to 16 again or damn close

 

I am curious as well, from time to time, my voltage is low when starting.

I have replaced the battery, alt, msd box, coil, opti, plugs, wires, MAF, IAT and still did not fix the problem. The computer and the the wiring harness may make the next list along with the in-tank and in-line fuel pumps. The worst part is it is intermittant.

 

Who all in this bunch is running under drive pulleys? I am and im considering running the alt pulley and doin away with the crank pulley and finding a belt that works. That alt will be spinning really fast then.

 

Did you all not read my reply to your question, im telling you ive been through this 3 times with my car about every 3-6 months its just something that has to be done?

 

I have the same problem but I have ud pulleys but I got the one for the alt. (od) that's suppose to correct the prob.

-year old die hard gold battery

-new, month old alternator

-cleaned corrosion at some of the easy to get to connections. Most were brand new looking.

...it only happens after the car warms up and i'm at a light idleing. I can really tell at night time b/c my headlights and interier lights will dim.

-b

 

We all just need to buy import cars then lol

 

you can buy just the od alt pulley here
http://www.thunderracing.com/catalog...vid=4&pcid=111

 

If you've done all the other stuff, test the batt and alt and clean terminals, grounds, etc., it's probably a wire or switch or relay somewhere that's making a bad connection.

I got lucky, my car wouldn't start sometimes (everything would just die when I turned the key, cycle again it starts), so I replaced the ignition switch and it fixed the voltage, right up there in between half and three quarters, and it doesn't drop voltage anymore under load. Two birds with one stone.

GM electronics have always been sub-par.

 

Ok I checked and cleaned most of the grounds. The ones I didn't check was the ground from battery to block, coil to frame rail(checked and cleaned frame rail but just made sure coil was tight didn't clean them up) and found another close to oil dipstick that I didn't check. I'll try to get them tomorrow. I cleaned the ones near radiator, frame rail, the one above the red accessory thing, checked the posts on battery no corrosion on them.
The red accessory where the hot goes looks to be in bad shape the plastic is cracked on it don't think that might have anything to do with it do you? Also should I take the starter off and clean it up were the wires bolt onto it? Anymore grounds that I'm missing? Also could bad relays or bad sensors cause the car to lose voltage.

 

Green Demon
What was up on the ignition switch?? What was your syptoms? This is something i might look into. Any more info on that?