Flickering or pulstating Headlights

[superchargeddrt]

I am going to get back into this one, lights still flicker, with all the mods. I have my instrument cluster out to look at my headlight switch and wiring. Some of the wires have some little humps in them with no discoloration. Does this mean they have bad continuity or they are getting warm? Thanks a bunch.

Might be that at some point they got hot. You say you did all of the mods, did you feed the "I" terminal of your regulator with a relay? Could be a bad ground at the regulator,the regulator itself or bad brushes in the alternator.

 

[coalman]

Yes, did the relay, regulator, and alternator replaced more than once. Going to replace the light switch since I have it opened up. Thank you

 

[superchargeddrt]

Yes, did the relay, regulator, and alternator replaced more than once. Going to replace the light switch since I have it opened up. Thank you

Also check the low/high beam switch. I had one that would cause the lights to intermittently go out. Usually on the darkest unlit road.

 

[superchargeddrt]

Yes, did the relay, regulator, and alternator replaced more than once. Going to replace the light switch since I have it opened up. Thank you

By the way, I hate to ask, but did you put the headlights on a relay as well? That would take all of the load off of the headlight switch and place it on the relays. I did mine myself and it makes the headlights noticeably brighter. You will need a couple of good quality relays and I used 12 gauge wire (less voltage drop). Its also a cheap fix. I would be happy to help but if you're looking for more of a plug and play option Crackedback sells a kit to do this. I think if I remember correctly its around $100.00.

 

[coalman]

By the way, I hate to ask, but did you put the headlights on a relay as well? That would take all of the load off of the headlight switch and place it on the relays. I did mine myself and it makes the headlights noticeably brighter. You will need a couple of good quality relays and I used 12 gauge wire (less voltage drop). Its also a cheap fix. I would be happy to help but if you're looking for more of a plug and play option Crackedback sells a kit to do this. I think if I remember correctly its around $100.00.

Yes, a long time ago. Thank you

 

[coalman]

Cleaned out all the connections in the headlight plug, installed new switch, and grounded switch housing tab to body, nothing changed. I just can't figure it out. Thanks

 

[RedFish]

Cleaned out all the connections in the headlight plug, installed new switch, and grounded switch housing tab to body, nothing changed. I just can't figure it out. Thanks

I recall 2 examples where the issue was the very last piece that one might suspect.... Ground cable from engine block to battery. Most notable story was the 68 Nova that belonged to electrician. No need to type all that here.

 

[coalman]

I recall 2 examples where the issue was the very last piece that one might suspect.... Ground cable from engine block to battery. Most notable story was the 68 Nova that belonged to electrician. No need to type all that here.[/QUOT

I meant to ask if the cable is bad internally how do you check it? The ground cable checks 0 ohms from battery to block. Any more ideas on this whole situation would be appreciated. Thanks a bunch.

 

[coalman]

New chapter to my electrical soap opera. When I first purchased the car it had a plug in the coolant temp sending unit hole, I purchased a new sending unit it never worked. Took the car out today the first time after replacing the light switch, bingo the temp gauge started working, dah???

 

[coalman]

Can my after market street fire ignition 5520 cause the voltage jumping around and how about the fuse panel doesn't the welded splice power it? Thanks

 

[RedFish]

There is one branch from welded splice that supplies a portion of the fuse box, brake lights, cig' lighter, dome lamp, everything hot at all times. Another branch from weld splice goes to ignition switch. A line out front that switch goes to another portion of fuse box. Supplies everything hot in run, wipers, turn signals, radio.

 

[coalman]

There is one branch from welded splice that supplies a portion of the fuse box, brake lights, cig' lighter, dome lamp, everything hot at all times. Another branch from weld splice goes to ignition switch. A line out front that switch goes to another portion of fuse box. Supplies everything hot in run, wipers, turn signals, radio.

Ok, thanks a bunch!

 

[coalman]

I have a question on this again. I came across an old post on this subject, it stated that pre 1969 charging systems have a ground wire off another FLD terminal on the alternator, is this correct? My shop manual wiring diagram does not show this. Thanks a bunch

 

[Mattax]

I have a question on this again. I came across an old post on this subject, it stated that pre 1969 charging systems have a ground wire off another FLD terminal on the alternator, is this correct? My shop manual wiring diagram does not show this. Thanks a bunch

Short answer is you are correct and they are wrong.
There was a '69 or '70 system that may have had a ground wire of sorts.
Its shown in the MTSC booklet as an 'insulated brush alternator'. The 1970 Alternator & Regulator (Session 269) from the Master Technician's Service Conference

Otherwise yes, the ground shown here...

..is the alternator housing.
The brush holder is cast into the housing.

Uses these brushes and one insulated horizontal brush holder

 

[coalman]

So mine needs to grounded? Thanks for the fast reply....

 

[Mattax]

If your setup has a positive controlling regulator, and both brushes are insulated, then yes - one needs to be grounded.

If your set up has a positive controlling regulator and one brush is insulated, then no.

If your setup has a 1970 up style regulator, it controls the ground connection.

 

[coalman]

If your setup has a positive controlling regulator, and both brushes are insulated, then yes - one needs to be grounded.

If your set up has a positive controlling regulator and one brush is insulated, then no.

If your setup has a 1970 up style regulator, it controls the ground connection.

I have the old style regulator, I can't tell if both or just one is insulated. A funny thing in my hard copy shop manual it shows the ground brush on the back of the alternator. Thanks again

 

[superchargeddrt]

I have the old style regulator, I can't tell if both or just one is insulated. A funny thing in my hard copy shop manual it shows the ground brush on the back of the alternator. Thanks again

With the old style regulator and a newer style isolated alternator with both fields isolated from ground, ground one field (doesn't matter which) and run the wire from your regulator to the other.

 

[coalman]

With the old style regulator and a newer style isolated alternator with both fields isolated from ground, ground one field (doesn't matter which) and run the wire from your regulator to the other.

I was thinking of just putting a jumper wire on the alternator ground, and grounding it to see what happens if anything. I have been screwing with this electrical crap for so long I am beginning to enjoy it...

 

[superchargeddrt]

I was thinking of just putting a jumper wire on the alternator ground, and grounding it to see what happens if anything. I have been screwing with this electrical crap for so long I am beginning to enjoy it...

That will work, I used to do it that way when I had the old style voltage regulator. I switched to the new style regulator for better stability.

 

[coalman]

That will work, I used to do it that way when I had the old style voltage regulator. I switched to the new style regulator for better stability.

Thanks, I will try that, maybe it will help the original problem, I have the relay installed, the system charges good, it just still bounces between 13 and 14 volts... I might still do that newer regulator, if I don't have to get another alternator. Thanks for help..

 

[Mattax]

I have the old style regulator, I can't tell if both or just one is insulated. A funny thing in my hard copy shop manual it shows the ground brush on the back of the alternator. Thanks again

Is it on the car? Try a mirror?

Roundback

Round back Isolated field ('starting in 1970)

Isolated field round back with one terminal grounded with jumper.

Sometimes earlier round backs are mutilated to convert them for use with two insulated brushes. See here
Round back alternator
All square backs have insulated brushes.

 

[coalman]

It is grounded to housing. Thanks a lot...

 

[coalman]

I put a jumper on the alternator ground, did nothing. I was wondering also why the pulsation goes away 1500 to 2000 rpm range, then starts bouncing again at idle?
Thanks

 

[RedFish]

I put a jumper on the alternator ground, did nothing. I was wondering also why the pulsation goes away 1500 to 2000 rpm range, then starts bouncing again at idle?
Thanks

Faulty voltage regulator will cause that. The condition suddenly appeared in my volt gauge needle a few days after I switched from amp gauge to volt gauge. I suppose I would have seen it in headlights, etc., also if I hadn't replaced the regulator right away.