Voltage Regulator Question 85 Brat

[newgen85brat]

Well in another related thread I talked of my Brat having problems with no power to the fuel pump until the engine starts. There is only 9 volts to the fuel pump during initial key turn and then when cranking. When the engine starts the voltage goes to 12.4. I read some other threads looking for answers and someone said the voltage regulator was bad. One question first, if the voltage regulator is weak or bad will the amp meter drop considerably when the turn signals are on? Also when the headlights are kicked on too. The ammeter drops about 2 volts as the turn signals are flashing. It used to worry me but not too much. Maybe this is the culprit with my fuel pump not getting power during cranking? Is the VR part of the alternator or is it separate? Thanks for the help as always.

[djellum]

i would say something in the charging system is a likely culprit. Reg is probably in the alternator, check an online auto parts store and see. the reg will be in the motor compartment and directly hooked to the battery if its seperate.

[edrach]

Normal for the voltage to drop while cranking. Nothing wrong with your alternator (or fuel pump from what I've been reading). You might have a weak battery, or bad connection at the battery or alternator ends. Voltage regulator is meant to keep the voltage from going too high for some reason or other, not too low.

 

jUst a suggestion, get a copy of How to keep your Subaru Alive. It'll answer some of your questions and also entertain you. There's an on-line copy floating around also. I bought mine for $10 on Amazon quite a few years ago.

Edited September 8, 2012 by edrach

[Twitch de la Brat]

Check your grounds and make sure all of your connections are clean. Attaching a ground strap to your alt would be a good idea as well. I have one connected to the mounting bolt.

A ground strap on your engine would be a good idea too, as your starter amperage has to go back to the battery and the longer the trip, the harder the start.

As for the Voltage regulator giving you fits, I wouldn't worry about it. Unless you start seeing your voltage go too high or your voltage start to stutter and jump, I wouldn't worry about it.

 

A nice upgrade to do if you're tired of your blinkers dimming your headlights is the Maxima Alt swap.

Bolts right in and it all connects up with some spade adapters if you want to keep your factory plug on your car. Hardest part is grinding down the spacer for the pulley and keeping it flat.

GD has a full writeup on it in the USRM I believe.

Well worth the money and time.

 

Twitch

[naru]

One question first, if the voltage regulator is weak or bad will the amp meter drop considerably when the turn signals are on? Also when the headlights are kicked on too. The ammeter drops about 2 volts as the turn signals are flashing.

 

NO.They are basicly unrelated.

 

The voltmeter drops w/signals because the dash and signals share the same power and ground paths.Poor(high resistance) connections in either cause the votage to drop w/the current increases.

 

Easiest way to find the "problem" is to put a voltmeter around suspect circuitry and check for voltage drops under high load.

 

IIRC,I measured 0.5 volt drop across the ignition switch and another 0.5 volt drop to the main ground under the fusebox.

Haven`t done any "fixes".Was thinking about adding a large ground wire from the battery to the dash ground and replacing the ignition switch.

 

Doubt there is anything wrong w/your fuel pump.

It doesn`t even need to run in order to start the car(unlike fuel injection)

[Loyale 2.7 Turbo]

... get a copy of How to keep your Subaru Alive...

 

Click on my Avatar and Scroll Down on my Public Profile to Reach it.

 

Good Luck!

Kind Regards.