Voltage regulator?

[austindavis1993]

Okay so i took my car in to have my battery and alternator tested, they told me my voltage regulator was bad, so i forked out 150 buck replaced my alternator and took it back to have it tested again just to discover that the voltage regulator is still bad? something seems a little bit odd to me i even put in a new battery. Also whenever there is any kind of sudden electrical load such as as climate control, or even something simple such as applying the brakes, i can see that there is a small surge in my electronics. PLEASE HELP. Car is a 93 mtx.

 

[EL SHO]

Besides getting the alternator replaced and a new battery, have you checked for any loose or worn out ground wires? The ground wire from the battery could use a little help bu adding more ground wires or a heavier gauge wire too.

As for the regulator, have you checked how much volts is your alt putting out when the car is fully warm? It should be around 13.5-14 volts at the batery posts and above 12v when all accesories are on. If so then your alt and regulator are Ok

 

[austindavis1993]

yeah I just tested it with a a voltmeter and it was within spec, and i tried cleaning up some grounds and whatnot, and it still seems like whenever there is a sudden load, it slightly surges; even just the brakes cause it. Its nothing too terrible but its just one of those things where it drives you nuts.

 

[Dirk37]

What do you mean by surge? Are you talking about an increase in voltage or a decrease?

If you're talking about a decrease, try checking the connector to the alternator power. Mine had severely corroded where the connector crimped onto the wire and caused my battery light to come on sporadically.

If it looks oxidized it definitely won't hurt to try replacing it. You can clean up the copper wire by soaking it on a solution of salt and vinegar for about 30 minutes.

 

[austindavis1993]

yeah like there is a voltage drop, with or without the car running, maybe i should add more ground wires. but i will see if the alternator power wire needs some attention too, but it seemed to look okay last time i checked.

 

[Dirk37]

If it happens without the car running as well, it's going to be a battery/connection issue of some sort, not the alternator.

How big is this voltage drop exactly? Naturally whenever you have a large load the voltage is going to drop so it may be nothing you need to worry about.

 

[rubydist]

the voltage regulator is built into the alternator on these cars. it is the most common point of electrical failure. it would not be the first time that a 'new' alternator had a bad voltage regulator out of the box.

 

[luigisho]

What ruby said. parts store alts and starters can be a crapshoot sometimes. also when alts go bad or fail they can **** your battery if you draw on it too much to compensate-- especially if you drain it all the way down. New or extra grounds are pretty cheap to try first

 

[austindavis1993]

Yeah ive noticed that sometimes when i have my headlights on and i go to turn on my defrost, the whole climate control shuts off and restarts itself.

 

[EL SHO]

the voltage regulator is built into the alternator on these cars. it is the most common point of electrical failure. it would not be the first time that a 'new' alternator had a bad voltage regulator out of the box.

I hear ya! In total I've replaced about 3 voltage regulators in my car aside from replacing twice the whole alternator in about 2 and a half years.

It's a matter of luck I guess when you go with a rebuilt alternator. I even managed to buy the voltage regulator by itself and I think I still have one laying around just in case.

 

[austindavis1993]

So i fixed it, the connection to the starter was loose causing flaky operation...these cars are so tempermental

 

[luigisho]

I've had it come loose more than once. Might want to check it again every once in a while

 

[rubydist]

the only alternators that I have gotten to last on the SHO are the NAPA lifetime warranty ones. all the others seem to be programmed to die just after the warranty expires...

 

[luigisho]

I take mine to a local rebuild shop. Work good but I did notice all the parts are still made in China