'86 3.2 Flickering Headlights

[Slocs]

Guys, last night while dropping my niece off at the train station I noticed that my headlight were flickering - almost like going to a 'half' full beam, then back to regular, across a cycle of about half a second. By the time I got home it'd stopped doing it, and 3 mins of revving up and down didn't make it happen again.

Coincidentally a couple of days ago, while idling in traffic the alt warning lamp came on. Revving to 1,000 rpm made it go out again.

A quick bit of pelican research suggests that the voltage regulator could be on the way out.

My question is as follows - is it safe to drive the 45 odd minutes to the mechanic, or am I tempting fate (and a boiling battery and any other high voltage electrical maladies), meaning I need to pull the alternator out at home?

Any help is much appreciated.

Thanks

Rob

[rusnak]

check your voltage at the battery at idle, with all accessories turned off. Should be around 13.2 to 13.5 ish or so.

[Slocs]

Thanks Rusnak - last night when the carm was fully warmed up at idle it was sitting at 14.0v (which seems too high). Last week when the alt light was coming on it was sitting at 13.6v at idle.

I'll need to get a volt meter that I can read while driving...

Rgds

Rob

[djcdmv]

Same problems I had... I replaced the Voltage Regulator and all is fine now!

Use this great write-up by Wil Ferch and it makes it an easy job.

Pelican Technical Article: 911 Alternator & Voltage Regulator Removal/Replacement

[Slocs]

Thanks Dave - I read that when I got home last night - he makes it sound easy!

I'd best order the regulator then.

Thanks again,

Rob

[LJ851]

Yes, get a volt meter you can read while driving. When my Carrera's alt went bad it would go to 17+ volts!!! I did have very bright lights randomly. 14v at idle is not wrong as long as it doesn't go a whole lot higher at revs.

[BernieP]

You can get a volt meter that plugs into the cigar lighter. Very handy.

Bernie

[rusnak]

If you do change the voltage regulator, it is indeed an easy job. Make sure you have a magnetic pickup tool and a very bright small flashlight and a good worklight.

[mnez]

Check the battery and surroundings for any wetness. If the voltage regulator was going bad, the battery may have boiled, spilling acid. Mine did, and it took a lot of baking soda and water to clean it up. The flickering lights are a classic sign.

[kidrock]

I don't believe that 14V is a sign of a VR taking a dump. I'd be more interested at looking at:

1) fuse,
2) ground, and/or
3) switch.

In that order.

[Slocs]

I've just had a poke around in the front boot, and fortunately there doesn't appear to be any moisture, so touch wood, the battery hasn't been too hot.

And of course when looking at the fan assembly I committed 911 error number one, and brained myself on the enginge cover! What's a mild concussion feel like?

Thanks again for all the guidance (got to love the forum!)

Regards

Rob

[Slocs]

Thanks Kidrock - I haven't yet checked the voltage while the flickering is happening (I hope to do this tomorrow). It appears from other posters in this thread and others that what happens at idle isn't representative of what happens elsewhere.

As part of the examination I'll be running through all the logical aspects of the headlamp electrical system.

Thanks again,

Rob

[porschenut]

I had precisely the same issue, which was resolved by replacing the voltage regulator.

[Slocs]

An update...

I finally got around to rigging up a mobile voltmeter - took the car for a 30 minute drive. The first 15 minutes the max voltage was 14.2, then whamo - 17.7 down to 14.6 up to 16.5 etc. I made a beeline for home and the cars now in the garage.

Just as well I ordered the voltage regulator from our host, as well as $220 worth of other 'essential' parts (well that's the way I described them to my wife!)

Thanks for everyones feedback - now what to do about the poor state of the fan shroud? Did someone mention Gibbs Brand...

Thanks again,

Rob

[kidrock]

yep, spikes like that indicate a bad VR....good call. I'd take the fan and shroud in and have them media blasted. If you do a search, there's a couple of guys that do super cherry work bringing back the natural finish on the fan, shroud and do a great job on the parts that need re-plating. I think I'm gonna go that way when my VR finally takes a crap.

[Slocs]

Thanks Kidrock.

I also took your advice on the electrical system review, and I'm replacing the tranny ground strap which looked a little ancient. Oh, and there's a whole lot of old stereo / cell phone wiring that's also got to go.

Regards

Rob

[Slocs]

Spent an enjoyable 2 hours this morning replacing the regulator. Wil Ferch's guide (as linked above) was spot on.

The job really wasn't that hard, just fiddly. And yes, having a magnetic pick up tool is quite handy.

The voltage is now between 13.8 and 14.1 depending on RPM and load.

Thanks for everyone's help,

Regards

Rob

[victatwin]

Hi Rob, had the exact same problem 6 months ago, (1985 3.2 motor) ,had high volt readings as well as a boiling battery, changed regulator and voltage output returned to normal BUT there was a two fold problem as the lights kept flickering, due to the diodes failing (auto elect said this) I had to pull everything out a second time and put a recon alternator from California in and no more problems, Has your light flickering stopped? The auto elect said the alternator could have lasted for a few good years yet but I was happy to pay extra and replace it just to get rid of the flickering. Cheers from Australia

[Slocs]

All good thanks Victatwin.

No flickering, and output voltages all within spec.

Regards

Rob

[Omegablueray]

I've also been told by my parts guy to check the tension of my belt on my alternator. If slightly loose can cause the voltage to change. But that an easy fix to changing the VR and alternator.