Looking for help solving my volt reading on my brat.

 

It reads out under 12v on the dash, which is causing the wipers to slow and heater to blow slower. Put a multi meter on both the battery and alternator, noth reading in the high 13s. Double checked grounds, and then did the maxima alternator upgrade. Still pretty much reading out the same, but now im noticing random voltage spikes up to 18v on the dash readout and all the ligts get brighter and everything moves faster for a minute. All the fuss are good. Im thinking maybe voltage regulator, is there something else im forgetting or need to look into?

 

I dont really mind if the dash voltmeter reads incorrectly, so long as it doesnt affect lights, wipers and heater.

 

Any help would be appreciated

More than 1 issue.

 

1. Your new alternator is NFG-voltage regulator.

 

2.Bad ground or power supply to the interior.Probably ground.

 

Interior ground is under(above really) the fusebox,

Measure the voltage between here and battery - w/wipers etc.operating.

 

Check power by measuring voltage between the lighter socket and battery - w/wipers on.

Have a look at the wire between battery positive and the fusible link box.

I had to redo the connections on both ends.

Measure voltage on both sides of the fusible links.

More than 1 issue.

 

1. Your new alternator is NFG-voltage regulator.

 

2.Bad ground or power supply to the interior.Probably ground.

 

Interior ground is under(above really) the fusebox,

Measure the voltage between here and battery - w/wipers etc.operating.

 

Check power by measuring voltage between the lighter socket and battery - w/wipers on.

Have a look at the wire between battery positive and the fusible link box.

I had to redo the connections on both ends.

Measure voltage on both sides of the fusible links.

 

Nfg voltage regulator??? Im not familiar with what that means

NFG=No Frigging Good

Edited November 13, 20169 yr by naru

NFG=No Frigging Good

Ah ok... wierd, had it tested before i put it in

Intermittent problems come and go, so can sneak by a test.

I'm with Naru on this. Add to that the EA81 series had weenie alternators to begin with and really didn't have enough power to run the wipers, lights and blower.  The voltage spikes are definitely a regulator issue which means replacement so you might as well do the Maxima alternator swap and be done with low power output issues. I did it to one of my Brats, No more slow wipers and dim lights. Great upgrade.

I'm with Naru on this. Add to that the EA81 series had weenie alternators to begin with and really didn't have enough power to run the wipers, lights and blower. The voltage spikes are definitely a regulator issue which means replacement so you might as well do the Maxima alternator swap and be done with low power output issues. I did it to one of my Brats, No more slow wipers and dim lights. Great upgrade.

I alrrady did the alternator swap, cause ya the original ones are pretty wimpy. But I grabbed mine from a junkyard, so I probably just need to get a brand new one.

Ive come across this black box with a mistibishi emblem on it while trying to track down my voltage issues, what the heck is it, and why are there darn mistibishi parts in my subaru ????

That's the Fuel Pump Control Unit, (FPCU).