Voltage regulator

[Pritchard]

I have a '74 2.0L that is pretty much stock.

I think I read in this BBS some time ago that someone purchased a voltage regulator from their FLAPS. Can anyone verify this?

I'm thinking I might need a new voltage regulator. Here's why: when engine is running, all lights will flicker (dim then bright) and the voltmeter will fluctuate between 12 and 15 volts. I know that the volt. guage is not to be taken too seriously but it does coincide with what is happenning with the lights. I know that the guage will fluctuate when the turn signal is on etc., but this is not the case here.

Could I have a bad regulator or, heaven forbid, a bad alternator? How can I test either of these two parts? By the way, the alternator belt is tight.

Any thoughts on this would be greatly appriciated.

David Pritchard

[paulhagedorn]

I know this sounds pretty simple...and you may have already done it but...

First things to check would be the connections to the battery. I would take them off and take something like steel wool...or that tool that you get(can't remember what it is called) and scuff up the posts on the batter and the inside of the connections so that you are getting a good connection. You might have a bad alternator, but the only real way to check it out would be to take it out and have an "armature" place check it out to see if the brushes are worn.

I am guessing the dimming only happens when the lights are on and you are at idle...this happens to my car when at idle and I press the brake pedal, causing the brake lights to come on. I also just had my alternator checked this past summer because I thought it was bad. The place said it was perfectly fine, even though UH-OH Zone couldn't even figure out how to hook it up correctly and assumed it was bad.

Anyway, I made a story out of something very small that might not even be your problem.

HTH,
Paul

[paulhagedorn]

Oh, I also forgot to tell you to clean up the connections between the alternator, starter, and battery.

[efeinsmith]

And don't forget the ground strap on the rear of the transaxle to the car body.

[Dave at Pelican Parts]

Forget the stock voltmeter. Or rather, figure out what yours reads "normally", and see if its behavior starts changing from that.

Get a half-decent quality voltmeter (even the cheapie FLAPS/Radio Shack ones are fine for this) and measure the voltage across the battery terminals. Not the clamps, the terminals themselves. You should see ~13V-14.5V when the engine is above 2000 RPM, no matter what kind of load (lights, etc.) are on--unless you have a monster stereo or some such.

If it drops below about 12.65V at idle with the lights on, you can start worrying a bit.

--DD

[EDIT---]

Check Jim T's charging system troubleshooting guide in the Tech Articles section of this site. http://www.pelicanparts.com/techarticles/914_alternator_troubleshoot/914_alternator_troubleshoot.htm

Aftermarket voltage regulators are available at your FLAPS. They may or may not have the screw-holes that line up with the holes in the side of the relay board, so they may not be as well held in as the stock one. It's OK to bring your regulator in with you when you get the new one. Before you buy the new part, open up the box and compare with the old. Any FLAPS that doesn't let you do that isn't worth patronizing.

[This message has been edited by Dave_Darling (edited 02-16-2001).]

[Pritchard]

I guess I should have said that this happens when I'm just sitting there in the garage with no other drain on the electrical system at all other than the lights. No brake lights, flashers, etc.

I do need to check all connections. I know the battery terminals are OK and clean.

Thanks for all your input. I'm going to try to find a regulator this weekend and try it out.

Thanks again.

David Pritchard

[Rouser]

If you decide to replace the OEM-type voltage regulator, there's an electronic-type unit out there (Borg-Warner: Part Number R588). I purchased it at Pep Boys, but I'm sure it's available elsewhere.

No, it doesn't offer any performance improvement or advantages. Since it's electronic (whereas the OEM unit is mechanical in nature), you only get epoxy-encased piece-of-mind.

It's half the size of the OEM brick, and utilizes the original, tiny phillips-head screw to mount it. It has a connector lead-out that's inserted into the relay board one-way only. Pretty-much idiot-proof.

[greenwood]

I got my voltage reg. at AutoZone.
I went to their website and searched the inventory of the stores near by. When I went to the store to get it the guy had a look on his face like "good luck if you think we've got one of those things."
To my surprise, they had quite a bit of 914 stuff...mostly electrical like VR, alternators, I think starters, plug wires, etc, etc

jeremy

[porsche914gt]

I got my regulator from FAT Performance. It needed a little modification, as the screw holes didnt line up exactly. No big deal. $35 for this nice little solid state unit. Much better than the stock one. It may be the same unit Pep Boys sells, for probably less.

[mejulihn]

David,
I think it is likley you need to replace the VR. I recently had the same problem you are describing. Like Rouser, I purchased and installed the Borg-Warner unit (R588) and the problem went away. It installs in minutes and is of course solid state circuitry.