lights flickering, distance/heat related

[johnunit]

so I've got the light-flickering blues. I know this is a common thing, but I supposedly have the 100amp alternator and have not had this issue before, it seems to have come about during the winter.

It seems to increase with distance/heat. I have cleaned all the connections at the starter solenoid, and all but the thickest on the back of the alternator (won't come off with alternator mounted and I don't wanna hurt it). I also have a new negative battery cable.

The initial startup (from cold) cranks just fine, and the first few seconds of headlights on have no flickering. The headlight/interior light flickering gets worse as it heats up, but the playing around with wires has prevent the alternator light from flickering it would seem. It cranks very slowly after being hot, too.

The only hints I can get is the alternator MAY be unusually warm after running, and some of the wiring has cracked (and been covered in electrical tape, yeah I know) coming out of the regulator.


Any ideas? regulator? alternator? places to stick a voltmeter?

[P72Ford]

I jhad this problem with my red car. Changed the regulator, which helped, but it never really went away completely.

[1987cp]

^ You "jihad" a problem? :lol:

But yes, my '79 flickered badly when I got it, and swapping the alternator did no good. Swapping the regulator smoothed it out. Best fix I know of is to remove your outdated lump and install a 3G.

[johnunit]

Heck yeah he jihaded the problem. Death to Problems! *random AK47 shots in air*



That's the news I was dreading. From the pictures online, it looks like I have to re-pin the new regulator? It doesn't look like anyone even sells one that comes with enough wiring to replace the stuff that's attempting to sheds it's insulation, which may well be the problem itself. bleh.

[1987cp]

Oh, your regulator wiring is messed-up? That sounds annoying.


For my regulator, I just bought the one they had listed for my car at AutoZone and plugged it in. Cost about $10, zero-hassle installation. Since I've always assumed the regulators were basically the same from '65ish (when they first introduced alternators instead of generators) through the '91 100A models, I have no clue what could possibly need to be "re-pinned".


Do you have a cheap source for large-case 3G alternators?

[johnunit]

I meant re-pinning as in having to individuall insert each wire correctly, as all the pictures I've found show no wiring at all coming with the regulator.


I'd go 3G (probably will eventually) but time and money are big factors here. Due to a series of unfortunate events, this will basically be the family's only ride for the next week.

[86VickyLX]

3g swap would be good. And it would get rid of that fugly regulator on the fender.

[gadget73]

The regulator connector should be a large plug that contains all 4 or 5 wires.

make sure the ground to the regulator is good. It should be mounted to the fender, or have a wire going to the fender or something. If thats flaky, the voltage won't be stable. Also make sure the connection between the alternator case and the bracket is good. Stick a voltmeter from the alt case to somewhere handy on the engine or the battery -. You should see less than 0.25 volts difference. At one time I had some crust around the alternator bolts and I was losing close to a volt from alt case to the engine. Fixed that and my lowish charge voltage problem went away.

[johnunit]

The regulator connector should be a large plug that contains all 4 or 5 wires.

make sure the ground to the regulator is good. It should be mounted to the fender, or have a wire going to the fender or something. If thats flaky, the voltage won't be stable. Also make sure the connection between the alternator case and the bracket is good. Stick a voltmeter from the alt case to somewhere handy on the engine or the battery -. You should see less than 0.25 volts difference. At one time I had some crust around the alternator bolts and I was losing close to a volt from alt case to the engine. Fixed that and my lowish charge voltage problem went away.

thanks. I painted the alternator bracket and the bolt is only sitting partly on the unpainted part that it left behind in it's previous position, so that and the ground is worth checking.

The black wire going to a little black cannister isn't the regulator ground, is it? I was pretty sure from my memory of the wiring schematics (not with me right now) that it was just a radio noise surpressor, but it is a black wire and it was coroded to the point where I just removed it rather than risk it doing something funky.

[GM_Guy]

Have you got a voltmeter? Whats it showing?

The little canister if cylindrical, with only a single wire, is indeed the noise suppressor (condenser/capacitor). The wire is NOT the ground. The A terminal it connects to is +12v and goes back into the harness, and to the suppressor. If you removed all the wires that connect to this terminal on the regulator, and not just the condensor wire, it won't operate correctly. Some would argue running without the condesnor could lead to funky things to.
The regulator grounds through its case.

Swap Notes for a 3AG;
-Large frame 3AG will drop into place of the 100amp unit size wise. 1993 (or is it 1995?) 3.8L Taurus, 130amp unit. Its what I used.
-You'll need the "i" wire that connects to your external regulator (dash light, light green/red).
-You'll need the "A" wire (the one that connects to the same place the condenser wire connects.
-And the 'B' wires (even though you will be adding an additional bat wire ;-) ) that connect to the alternator.

Alex.

[johnunit]

Have you got a voltmeter? Whats it showing?

The little canister if cylindrical, with only a single wire, is indeed the noise suppressor (condenser/capacitor). The wire is NOT the ground. The A terminal it connects to is +12v and goes back into the harness, and to the suppressor. If you removed all the wires that connect to this terminal on the regulator, and not just the condensor wire, it won't operate correctly. Some would argue running without the condesnor could lead to funky things to.
The regulator grounds through its case.

Swap Notes for a 3AG;
-Large frame 3AG will drop into place of the 100amp unit size wise. 1993 (or is it 1995?) 3.8L Taurus, 130amp unit. Its what I used.
-You'll need the "i" wire that connects to your external regulator (dash light, light green/red).
-You'll need the "A" wire (the one that connects to the same place the condenser wire connects.
-And the 'B' wires (even though you will be adding an additional bat wire ;-) ) that connect to the alternator.

Alex.

all I did to "remove" the noise surpressor was cut the wire that went to the regulator from the cylinder. It's still sitting on it's little bracket. I had assumed it would only make the radio a bit staticky, but if it is potentially going to cause more issues re-wiring it is easy enough. I just saw missing insulation and didn't want to risk a short/fire.

If the alternator needs a good ground through the alternator bracket, specifically the stamped piece that the top bolt attatches to, that's probably my problem because at least part of the alternator is sitting against rustoleum there, and I did notice the issues starting after the belt was played with (yes the tension is good).

I'll check the ground at the regulator, and de-paint the alternator bracket, then check for voltage drop from alt case to engine block.

[johnunit]

Cleaned up the alternator bracket and no difference. Washed the car and It got a bit worse. I'm thinking it's the cracking wiring at the regulator.


Is there any source for getting the correct ford coloured wire? I'd rather not have it changing colour.

[1987cp]

A fancy electronics store may have striped wire. I think. Can also try online electronics suppliers, or if you're desperate maybe go begging at a dealer parts counter. Obviously, it'll work OK even with plain wire and generic crimp terminals.


Seriously, though, if the wiring's buggered, I'd say it's probably high time to consider updating to a 3G. I've got very little against a 1G system - that works, and is adequate for your needs. To me, the wiring is probably not worth repairing unless it's for some crazy resto purpose.

[johnunit]

Picked up a voltage regulator and pigtail. You need the pigtail unless you wanna get creative and permanent with the wiring, at least with the aftermarket regulator I got.

Problem solved, for 35 bucks tax in.

[1987cp]

35 bucks? Ouch.

So were you just not able to obtain a direct-fit regulator?