Electrical Mystery

I changed out 5 'one wire' alternators on my old Explorer and several on an older Mustang.

It's always the voltage regulator. It's that small grey or black thin wafer package looking thing that goes on the back of the alternator.

It has 'gel' filling that gethot and seeps out, slowly causing disfuntion of the regulator. I finally just said, OK, gotta live with this, cause I can change them out in under 10 minutes in the parking lot at Auto-Zone, and even knew theexact size wrenhes to do it. EVERONE FAILED. Within a few days. I just let my headlights pulsate at stop lights. They went to full, steady intensity at driving RPM.

There' too much heat for the gel to withstand. Always sweats out.

That's my experience with Motorcraft and Autolight alternators. Hope that's not the case for you. But you can just buy the 'regulator' package at Auto-Zone for about $60.00. Remember to push the brushes back inside of it and hold them in place with a straightened out paperclip when you re-install them. You'll probably panic when you pull the regulator off the back of the alternator and see the brushes pop out. Tiny hole hold both brushes retained while you put the 3 or 4 tiny screws back in place holding the alternator and regulator together.

Remember to pull the paperclip out after reassembly of the alt/reg. or your won't get any charging at all.

Let us know if this is the fix. Been there, done that!

Usually when the A/C is turned on, the engine speeds up a little to compensate for the HP requirement, which spins the Alt faster, and the pulsating current steadies.

Rodger
Believe it or not I had this same problem
in Feb. this year.I have a 4.6 with new style alternator. Pulsing amp gage, lights flickering at idle. Searched the web to no avail. Turn on fans, pulsing goes away. turn off fans pulsing gone for a few minutes, then returns. Went nuts checking grounds.
Could actually hear alternator making surging sounds. I even suspected the electric fuel pump. The only thing I could think of that surged. Placed volt meter at battery. Thing jumping to 16 volts!

OK here's what I discovered.
Hopefully your's is the same.
Got a real good battery? I do
Fully charged that real good battery after
working on the car? I did
Well it appears that the battery is staticaly
putting out enough to turn off the internal
regulator. Then as voltage dropps just below
the threshold it kicks back on,off again.
Turn on a heavy load everything is fine.
Try draining the battery a little. Like
leaving the lights on for a while.
Do you disconnect the battery when your car sits?
If so and you are going to drive it, in
a few days or even a few weeks. DONOT put the
battery on a charger. Let your new alternator
do the work.
Hope this helps!
Let us know.

Thanks guys,

I'm working on it and I'll let you know what happens.

Rodger

Rodger,
If you do decide to change the regulator in your 'one wire' 100 Amp alternator, and If that 'fixes' the pulsating effects you are getting, and If, when you remove the old 'internal' regulator from the back of the alternator, you see that it has been 'sweating' the gel out (greasy, colorless film coating on the edges of the regulator, well then, If all these elements are in place, then, when you re-assemble it, and cruise her on a test drive, I'm fairly confident that the 'problem' will be 'fixed.'

But, If this fixes the 'problem,' then the problem may be only templorarily 'fixed.' So, therefore, I suggest that:
(1) You again remove the regulator and (i) squirt some 'Super Glue' around the perimeter edges of the regulator, that is: around the seams where the regulator halves were assembled at the factory; (ii) re-assemble the regulator and alternator, then coat the regulator with 'Epoxy,' with a heavy coating of the 'Epoxy' around the edges of the regulator. [This will (a) prevent the gel from sweating out again; (b) insulate the regulator from the heat; (c) increasing the lifespan of the alt/regulator]; (d) if you ever have to replace the regulator again, the regulator can be seperated from th alternator with the screws and a smack with a hammer; and (iii) make sure there are no heater hoses running behind the alternator [route them over the top of the alternator/regulator]. This will (a) let the alt/reg pass air through the ducts and run cooler; and (b) keep the heat from the heater hoses off the alt/regulator.

Hope this is the real Fix and it works for you. I'm fairly confident in this regard. Tell me if I'm wrong.

Ron

Thanks Ron;

I'm still trying different things. What did you use to insulate the internal regulator?

Rodger,
they were all under warranty, and I changed out a lot of them, got to the point that they just kept failing within a week or month, and it wasn't a Pantera I was gonna keep for life, it was an Explorer, so I didn't even think of insulating the 'internal' regulator (which was actually on the backside, outside of the alternator). I just gave up, and let them flicker, pulse, whatever you wanna call it. I got rid of the Explorer last year and got a Toyota 4x4. I don't even know if the 100 amp one wire alternator (like you have) has an 'internal' regulator or if it's on the back (like mine were), but I know they fail from heat and they sweat that gel out. I thought about the epoxy to insulate it (the regulator) and hold it together under heat stress driving to work last week and thought I'd suggest that.

I know it's your regulator causing this flickering though. Very high confidence level. 99.9%.

I got a 100 amp alternator with the four wire set-up from NAPA, it's huge, 6" diameter and 1/2" to 1" thicker as well, so I had to squeeze it in, and bang out the engine cover with a hammer to accomplish this installlation. I wrote up a little how-to on this subject on PI's board here, but placed it in the Announcements section accidentally about 6 weeks ago. No problems with this set-up. Starts alot faster, with quicker response for the 6,000 volt ignition coil. All this stuff take juice to fire the devices. The Explorer had big juice requiremnts too though.

My regulator is on the firewall, well away from the engine, headers, heat, and does not rely on tiny contacts to pass large amperage loads through. My alternator has huge magnets and coils, so is able to put out bigger amperages at lower rpm as well as higher rpm. My theory was the smaller 100 amp alternators struggle to put out the big amps at low rpm and cause undue drain on the regulator as it tries to perform it's function at low rpm, no problem at higher rpm for the smaller 100 amp alts. My theory, and it's not science, engineering, proven or otherwise, but seems to make sense and work. I want reliability, but am willing to learn.

I just figured you and a bunch of other guys got cash laid out and have a 100 amp alternator already, so I'd post the suggestion to insulate the regulator. Clear the path for air flow behind the alternator also. In science, Work has equations with Heat as an unwanted byproduct, and electrical current as the desired product. Heat build up will also decrease the efficiency of electrical devices, such as alternators, and cause regulator failure.

This is an important issue for all of us, so please let everyone know what solutions work. I'm sticking with my soltion, experience and all. I did not chose my solution because I was unaware there were 100 amp 'bolt-in' alternators available. I knew the regulators would fail due to the one wire (indicating 'internal' regulator) design.

Regards,
Ron

An update on my electrical mystery...

First, I wish to apologize since the last few months have been uncooperative in allowing me to spend alot of garage time with my car. With over 100 degree temps here in Bakersfield,California, and my work scheduled delayed this report. Plus I'll admit it, like Bosswrench, I'm electrically challenged (but I'm learning really fast!).

Now, what I've found...

Recently, I've had a fan that would not operate. Since I have an aluminum Fluidyne radiator layed down with 2 sucker fans and hood vents, the car really never overheated or was slow to overheat even with only one fan in 98+ degree temps. I installed these updates, myself.

I discovered that one of the relays was bad and I replaced it (now both fans work). During this time I found 2 red wires, one cut short & one attached to one of the fan circuits, that I could not explain and did not show up on the wiring diagram. I traced these wires and found that they were connected to two diodes that were mounted on the grill supports at the very front of the car. Only one red wire was connected, that's an open circuit! I know from Jack's responses that they are normally placed to avoid electrical feedback from the fans. I decided to eliminate the diode circuit and watch the results as I repeatedly drove then turned off the car. No difference except, now my lights no longer flicker, pulsate or blink even at idle or with the turn signals on.

My conclusion...

The previous owner had a stock radiator setup with stock, front mounted "pusher" fans. He must have been having problems with "run on" or some other trouble and hence installed the diodes. Either I cut one of the diode wires (very possible) during my upgrade or it was previously done (can't remember if the lights flickered when I bought the car) but, there was an open circuit and as Jack DeRyke so often said, Lucas wiring will do really weird things with a bad ground, incorrect setup, etc.

So, that's it for now. I've driven this vehicle a number of times at night and if the battery is charged, there's no pulsating in the head or instrument lights or amp needle bounce.

I really hope this helps or at least starts the mental process flowing for those that suffer the same irritation with their lights. My discovery was by accident and was something that was over looked until I had to replace a necessary component.

Good luck.
Rodger