Recently took my evo 8 gsr into the shop for a service in which they diagnosed a faulty thermo fan controller, they replaced it and ever since ive picked it up it has developed a missfire under boost, also randomly brings on the battery light and hand brake light i also notice everything goes dim when i turn on my head lights, in one case i parked up idle went all weird reving between 1-3k then flashing the battery light brake light engine light came on and then all three ayc lights come on and the car died shortly after.

Ive allready read about faulty alternators but i tested mine and was getting a solid 14-14.4 v. Could this be anything else or related to the new fan controller ??

 

Alternator faults are known to be intermittent, you alt could be on the way out.

What I would do is keep a multimeter in your car and next time you have issues quickly go test the voltage. If its anything less than 13v when the issue is happening its probably your alternator.


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check your connections on the battery

 

Id do as said above, could maybe be a bad regulator cause 14.4 is on the high side, especially if you see your lights dimming sometimes.

 

Alternator

 

Easiest thing to so is have a voltage gauge in the car so you can see the voltage as soon as the car starts acting up. They have those $2 voltage gauges on eBay that plug right into your cigarette plug.

Arent' regulators inside the alternator now days on 99% of the cars? Most people don't even rebuilt alternators anymore

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thanks for the advice guys, already sorted it out, as suggested it was the alternator working intermittently, i hooked up a volt meter ran it into the car and took it for a lap around the block. Found that when the car warms up the alternator starts producing weird values. replaced alternator and its a rocket ship again

 

Yea usually when the alternator heats up the rectifier diodes inside the alternator start acting up when they are bad. Sometimes its the brushes but diodes go bad a lot more

Its just kinda sad that because of a $.50 diode we have to buy a $200+ alternator unfortunately since most alts are not easily rebuildable now days.


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Yup. Battery + brake light are our cars' idiot light for the alternator.
I didn't get those, so had to spend a year diagnosing the problem lol
a $10 Harbor Freight alternator tester ended up doing the trick! Go figure.
: lol: