I do own a voltmeter, and know a bit about car stereo but this is perplexing me. What's happening is all the electrical in my car is surging. I first noticed this one night because I saw my headlights flashing on the car in front of me. The gauge cluster will surge, the interior lamps will surge, and all head/tail lamps, however my aftermarket head unit does not. It's a fast blinking the lights never go completely out. I have visually inspected all fuses, and made sure there were no burnt out lamps. The only thing I can think of is does the alternator have a voltage regulator that may have gone bad, and is there a way to test it? Any other ideas? I think people think I am a cop, haha. Thanks for the help!@
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mitsuturbo
Well-known member
It's very likely that you've got a problem with your alternator. PS fluid likes to drip on them, which apparently is not healthy for them. I've had a lot of bad luck with DSMs, GVR4s and alternators. A known good original alternator seems to be much better than replacements from C/S/K or napa. I tried alternators from Checker for a bit, and after a LOT of problems in very short order (5 replacements in 3 months, one of which only lasted 3 days, another.. 2 weeks) I got one from VatoZone, and they've held up fairly well (usually last about a year). I now always keep a spare on hand.
Having said all that, it's pretty apparent that I'd personally suspect an alternator problem first thing.
Having said all that, it's pretty apparent that I'd personally suspect an alternator problem first thing.
Your alternator is likely on the way out ( regulator or diodes ).
You notice the pulsing lights at night, well, because the headlights are on and drawing more amps/power than the alt can provide.
Put the DVM across the battery ( while running and lights/stereo off ) in DC mode. Should be at 13v or higher, preferably 14v. Then turn the lights and stereo on and check the voltage again. Should be the same reading, again around 14v. Lower than 13v the alternator is tired/weak.
Next put the DVM in AC mode and check while the car is running. If you have more than 0.25v/AC the diode pack is bad ( regardless of the DC readings ).
You notice the pulsing lights at night, well, because the headlights are on and drawing more amps/power than the alt can provide.
Put the DVM across the battery ( while running and lights/stereo off ) in DC mode. Should be at 13v or higher, preferably 14v. Then turn the lights and stereo on and check the voltage again. Should be the same reading, again around 14v. Lower than 13v the alternator is tired/weak.
Next put the DVM in AC mode and check while the car is running. If you have more than 0.25v/AC the diode pack is bad ( regardless of the DC readings ).
Wow thanks guys. KTMrider that's exactly the trouble shooting info I was looking for.
So i Just got some readings the alternator is running between 13.2 and 13.4 volts it fluctuates a few hundreths both with and without load. In AC mode I was getting a reading of 27, I see you said .25v I believe I was using a different scale, does the .2 difference mean this is my culprit or is there a small margin of error?
Thanks again.
Oh ya btw is my car going to die on me if the diode pack is bad, or it driving on thin ice and who knows? I won't be able to fix it until Friday.
Thanks again.
Oh ya btw is my car going to die on me if the diode pack is bad, or it driving on thin ice and who knows? I won't be able to fix it until Friday.
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Replaced the alternator today and thus far the problem is fixed, however I haven't been able to run the car for long because I noticed I have two holes in my radiator so tomorrow I'll be replacing that! Gotta love 19 year old cars.
Glad you got her running ( kinda due to the rad ).
On the AC test you should see less than 0.25 volts or 250 millivolts ( mV setting ). If it was 27 volts AC the diodes were definitely toast. Great link here click for more info.
It appears our alternators are very sensitive to oil baths plus close quarters to the turbo. Mine died not long after a dipstick popping incident that spewed oil on the alt. PS pump leaks also get em.
On the AC test you should see less than 0.25 volts or 250 millivolts ( mV setting ). If it was 27 volts AC the diodes were definitely toast. Great link here click for more info.
It appears our alternators are very sensitive to oil baths plus close quarters to the turbo. Mine died not long after a dipstick popping incident that spewed oil on the alt. PS pump leaks also get em.
