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Alternator or regulator?

EfiniX

Well-known member
Joined
Oct 18, 2012
Messages
647
Location
portland, or
So my alternator crapped out a few months back and I replaced it. Sadly, I didn't have time to wait for an OEM unit and just grabbed what oriely had on the shelf. I notice that my voltage never goes over 13.8, and at idle, it's around 13.5. WOT pulls, about the same as idle.

This morning I had on lights and accessories and my AFR was lean, an indicator that my voltage had dropped. Sure enough, 13.1.

So did I get a crap alternator and my regulator is hosed up, or are these cars picky and I should have gone with something that puts out more amps than stock?
 

MellowVR4

Well-known member
Joined
Jul 25, 2009
Messages
1,662
Location
Milwaukee, Wi
Usually its the regulator that cant take the heat.
 

thomcasey

Well-known member
Joined
Sep 24, 2014
Messages
907
Location
Indianapolis, IN
Is your downpipe wrapped?
 

EfiniX

Well-known member
Joined
Oct 18, 2012
Messages
647
Location
portland, or
Down pipe isn't wrapped, but I do have a steel heat shield installed. Might not be enough I suppose. Is that the running theory, then? I know I've seen a thread with a product that relocates the regulator...

Also, what's the correct amperage for these cars?
 

thomcasey

Well-known member
Joined
Sep 24, 2014
Messages
907
Location
Indianapolis, IN
Stock VR4 alternator is 90 amps. Mine has no issues running with a 75amp. Yes, the heat causes the regulator to sag and fail. The alternators are poorly designed for cooling being that the cooling blades are on the inside.
 

EfiniX

Well-known member
Joined
Oct 18, 2012
Messages
647
Location
portland, or
Hmm... Well I'll have to check it when it's cool to see what it's putting out. Easy enough to shield the alternator more. Just hoping the regulator isn't already spent. /ubbthreads/images/graemlins/smile.gif
 

MellowVR4

Well-known member
Joined
Jul 25, 2009
Messages
1,662
Location
Milwaukee, Wi
One time the alternator crapped on me, changed it with a napa reman, and it dumped on me 2days later.
 
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