Ok, my 86' NA runs fine but it has some electrical gremlins. I have a new battery and alternator and both read 14 volts at idle. However, once it's under load (lights on, heater full blast) voltage drops to about 12.3 to 12.5. Also, whenever the brake lights or blinker is on the gauge cluster lights dim then go back to normal once the brake or blinker is turned off. Has anyone experienced similar problems and can help? Any help is appreciated!

 

sounds normal to me!

the stock alternator is only like realisticly like 60 amps or so max (not at idle), with lights and heater on its drawing alot of amps so its normal for the volts to go down expeclially at idle.

if you turn somthing on and u get a big dip like to 11 or lower then there might be a short somewhere.. but sounds like your car is probably fine.

 

alt is starting to fail.

Voltage should never ever ever be under 13.5 volts, and should be at 14.4 at idle regardless of load

 

the dimming in the gauge cluster is ok? i was thinking it was possibly a bad ground since i also have 3800 rpm stalling when it's cold.

 

the problem is that this is the 3rd replacement alternator that's been put in it so that's not the problem for sure

 

Bumps are not allowed here, and will be deleted when found. Do not bump! Furthermore bumping in less than 24 hours (well alone 10 minutes) shows a complete lack of manners, and suggests the bumper is a spoiled child that thinks his or her question is more important than everyone elses.

What are you getting or replacement alts??? rebuilt (as found at most cheapo auto parts stores) or remanufactured???

They should remanufactured. Cheapo rebuilt alts only have the broken parts replaced and typically have only a 1 year life span.

 

Ok, we all know that once this thing sinks to page two it's history, that's why i bumped. It's a reman i'm pretty sure but it's only about 2 or 3 months old either way. The alternator story goes as follows: the regulator went out in the original so my dad replaced it. The whole alternator toasted about a month later so we bought a used one because it was only 25 bucks or so. The used one worked ok but we still weren't happy with the voltage (it was doing what the current one is, around 12.3 with lights and accessories going). During the winter my car took a dump on me and wouldn't start, after unsuccessful attempts during the night we came back in the morning to try once more before towing it, a jump and a flooded start got it going and it's been fine ever since, as in it starts every time. The voltage still sucked so we put in a reman. alt. and got about a .2 volt boost in idle volts but it still droped down to 12.3 or so with lights and accesories. That's the scoop, i'm still suspcious of a ground but if all i hear is alternator then i may got get a custom built alt with extra amps, those are a little steep so i'm looking for any other problems before going to that because a stock alt should work fine if everything else is.

 

IT'S NORMAL for a 1986 - 1988 model.


-Ted

 

well if the voltage is dropping under 12.6 volts, then you are running on battery power, as the alt is not even putting out enough juice to run the car.

I know Ted thinks its normal, but with a new or Remanfactured alt, the voltage should never drop under 13.5 volts on a stock car. If it does with a new or reman'd alt, then I would be looking at grounding issues, damaged wiring, or that the alt was improperlly installed.

A S5 or S6 alt (See sticky at the top of the page) would give extra amperage (80 amps- for a S5 alt, 100 for a S6) if there are extra electrical parts such as fog lights, stereo, CDI, Electric fan, etc.

Now a dimming of the lights at idle is normal, as the voltage should be dropping down from 14.4 volts to 13.5, but at no point should the voltage drop under 13.5 volts.

And used $25 alts are worth exactly that, and should never be expected to be anything other than a temporary replacement. I use a S5 Turbo alt on my vert, and with the extra 10 amps over a S4 alt, I do not have any voltage problems even with my fog lights on and with a CDI system. Remember although most people try to get an alt to last much longer, most are toast by 60-75K miles and ready for repalcement.

And if people didn't bump, more people would look at page two and page three...