black93

93 SR5 V6

This began as an intermittent issue only in very cold weather. It has now progressed to a consistent issue.

When i start the truck it only shows the voltage at the level of the battery charge, as well as the warning lights on the dash, low heater fan speed and dim lights. From this point, one of two things will happen:

A) The truck will run until the battery is drained and then shut down requiring a boost, or:

B)The charging seems to "click" on and everything returns to normal (no warning lights, good fan speed, bright lights, dash battery voltage fine.) I don't hear an audible "click" instead everything gets instantly better.

At times I have been able to force it to "click" by revving up the engine (I know this is bad for a cold engine,) but that is getting progressively harder to do.

When I have run the battery dead and attached booster cables, the truck instantly starts, runs and charges correctly. It really feels like a sticky relay that finally switches over. There is no progression in improvement or deterioration of the charging, it is either on or off. There is no squeeling or other sound from the belts.

Can anyone confirm if this describes a bad voltage regulator, or can you suggest a more likely culprit?

I hate randomly throwing parts at a problem hoping to fix it, which is why I have not already replaced the alternator.

MudHippy

It definitely sounds like it's your alternator/generator. That's exactly how they act when they're on their way out, seen it many times. You can test it yourself to be sure.
http://personal.utulsa.edu/~nathan-b.../2onvehicl.pdf

BMcEL

It's most likely the brushes. Super easy to replace and just a few dollars at the dealership.

black93

Thanks for the replys.

So I can feel confident that replacing the brushes is my solution?

BMcEL

Open it up and look at the brushes...if one or both are worn down all the way, that's your problem.

abecedarian

It does sound like something is wrong with the voltage regulator circuit.
It could be bad brushes or could be an issue with the fuse block under the hood- i.e. corrosion on some connection- or possibly the connections to the alternator.

Jump starting will give the alternator "good" voltage on the battery side and cause it to lock onto that voltage as a target.

I'd suggest checking your connections before you dive into tearing your alternator apart.

kooolr

advance or autozone will test this free for you. the best way is to just get another alternator, if your funding will allow. yes- brushes are cheap. regulators aren't hard to replace either, (because you're already there) but expensive. from experience- go for anything with a warranty!
if you have a picknpull local to you - its a a good opportunity to upgrade if you haven't done so already...e.g.: 100A mr2 is a direct bolt in. $20 or so here in SC pullapart.

as an aside for ideas-> i have a 140A Acura alternator i put a 160A stator in for my 92 3vz. i fitted a longer belt, & spliced (soldered and heatshrunk) the Acura connector to my factory harness. hope this info helps. any questions- PM me.

abecedarian

How about a write up?

BMcEL

x2. ...

kooolr

i'm putting together my notes. i wanna make sure i have all the info and sources available that i used to convert my charging system. one issue i have is getting the pics together. bear with me! it'll be complete in a day or so. thanx for the interest.

black93

This is what the brushes look like. I went ahead and ordered some.



They look like there is very little travel, and one is worn almost to the little stamp on the side of it.

BMcEL

I bet that's the problem...it's pretty uncommon for the regulator to fail. Remember to clean up the armature with some scotch brite.

black93

Appears to have worked. Just have to wait for a cold night to know for sure.

black93

Update. Looks like everything is good in extreme cold (ie -29 degrees.)
I did end up replacing the battery as well, but I still believe the brushes were the issue.

Arkman

Originally Posted by kooolr
i have a 140A Acura alternator i put a 160A stator in for my 92 3vz.

Quote:
Originally Posted by abecedarian
How about a write up?

x2. ..


X3!