Headlights flicker, losing charge when all lights turned on

Canadian Poncho · A Poncho Legend!

Headlights flicker, losing charge when all lights turned on

73SC · A Poncho Legend!

Geez Todd, you pretty much checked everything. Here's a thought, you say this only happens when lights turned on. Maybe you should be looking at the device that turns on the lights?

-- Edited by 73SC on Sunday 23rd of May 2010 02:49:59 PM

dualquadpete · Canadian Poncho Superstar!

Todd, had this problem with my 64. 1st. check to see if you still have the "braided" ground straps from engine to firewall or frame. This will "sometimes" cause the flicker. 2nd. your voltage reg. could be getting weak in the springs for the points. That was my problem replaced reg. & back to normal. I was going to up grade to internal reg. alt. but stayed with the orginal style. All my ground straps are there, usually they go in the "can", over the yrs. Hope this helps!!!

Canadian Poncho · A Poncho Legend!

I'm thinking of going to an internally regulated alternator. I also thought about using relays in which the headlights are wired directly to the battery and the headlight switch turns on the relays. CDNPONT, you were going to wire your convertible this way, weren't you? I've replaced the regulator already.

Ray, good point about the switch. Usually when a switch is toast the lights go completely out (circuit breaker). It also seems worse when the car is first started. As things warm up the flicker is less noticeable.

66 Beau · Poncho Master!

Do halogens pull more juice than regular headlights? I would think so but don't know for sure.

If the headlight pigtails are corroded or if the wires are damaged, they may need more than 12 volts to stay operating. As the headlights cut in & out, the system voltage would bounce. As soon as the headlight drops out, the voltage would bounce up and the headlight could re-energize. When the alternator is at full charge (RPM's up, cruising), the system voltage would be high enough to keep the halogens working.

I thought alternators were supposed to cut out when RPM's dropped - such as would happen when you put it in gear? I've had cars that would not charge the battery at low idle - even in neutral. Some would charge when in neutral, but judging by the headlight brightness, would stop charging when I put it in gear (until I got the RPM's back up). I know my cars with generators would stop charging at an idle - alternators aren't as bad, but I thought the ones with external regulator woudl still do this.

69-Tin Indian · Guru

When I was looking up parts for my old truck, in the "lighting" section, it read that if you decide to go to halogen headlights, you had to order a "beefed up" wiring set up in order for them to work properly as the old wiring of the '60's wasn't adequate. I had the same problem with my '69 ragtop years ago and replaced the light switch and the problem went away. The thing is, as Dual Quad Pete has alluded to, there's just so many things to trace and try before you get the exact cause and get it figured out. Good luck Todd. As usual, some key advice here.

Canadian Poncho · A Poncho Legend!

Finding a light switch might be tricky. Is the Impala switch the same?

65Camino · Uber Guru

With a headlight removed but not disconnected put a meter on the terminals and see what happens. If everything is stock you should have 10-11 volts. Wait until the flickering occurs and see what the meter reads. It sould point to the headlight switch. While it happens and provided it's extremely quiet listen to the switch, the relay inside should click on and off...!

Solution would be to wire your headlights with relays. Take a power source close to the headlights, I used the horn relay. Cut the headlight feed and run it through the relay with the other side going to ground. Run the new power source to the relay's high side and then onto the lights. Do this again for the high beams. You should have full voltage around 14volts!

Canadian Poncho · A Poncho Legend!

I might do that-run the headlights off a relay. Any way to do it without cutting the factory harness?

eeluddy · Uber Guru

My old 69 Nova did the same flickering. I put a new ground strap on it and that cured it.

427carl · A Poncho Legend!

Don't take it out at night ! solved my problem confuse

RAILSKINNER · Addicted!

Maybe the front lighting harness that plugs into the firewall is loose ?

Canadian Poncho · A Poncho Legend!

Could be. That still doesn't explain the huge voltage drop (that shows on my aftermarket volt gauge) that happens in sync with the flicker..

65Camino · Uber Guru

Use your existing headlight plugs as feeders for the new relay.

Pontiacanada · A Poncho Legend!

66 Beau wrote:

Do halogens pull more juice than regular headlights? I would think so but don't know for sure.

On the show "Trucks" they said so. Sealed beams: 2.5 amps, halogens: 5 amps.
They installed relays.

-- Edited by Pontiacanada on Tuesday 25th of May 2010 09:55:13 AM

davelacourse · Poncho Master!

OK I'll add another possibiltiy - I don't know if your headlight wiring is like mine, since you have a late model car (ha!), but from the headlight there are 3 wires and one of them is a ground (to the radiator core support on my car), if that wire is frayed or the ground attachment has corroded, that would be consistent with your problem. I had a bad ground on my park lights and the result was similar to your problem.

SImple fix if that's the problem. Close inspection should tell, eh?

Dave

wagon64sd · Guru

i know the high beam low beam switch can give you problems with the lights..

Johann65 · Guru

RAILSKINNER wrote:
Maybe the front lighting harness that plugs into the firewall is loose ?

Had exactly this problem on my 65 Malibu. Found that the connecting pins had become loose over the years and when plugging the alternator and lighting harness into the firewall, the plug pins lost their position and caused a bad connection.
Solved the problem by using epoxy to set the pins back in place. Have a good connection now with no voltage drops anymore. Lights are bright again.

65wagon · Poncho Master!

69Laurentian wrote:

This is a problem that has plaged me since I bought my Laurentian. It is now worse since I installed halogen headlights.

When I turn the headlights on, they flicker. My volt guage fluctuates at the same rate of the flickering between about 13-14 volts. Now when I place the car into gear the system quits charging and my gauge drops to just below 12 volts. Same thing happens if I am in park and turn on my brake lights with the other lights on. I have replaced the alternator, regulator, battery and cleaned the terminal strip at the regulator. No real change. The flickering is also in relation to the points opening and closing in the regulator (I pulled the cover off and watched). It's as if the regulator can't keep up with the load.

Any suggestions? The flickering, voltage fluctuation seems to disappear when driving steady.

Todd

my favorite topic. i run halogen bulb type units had similar trouble. the regulators have to match the alternator. ie they are all 12volt but the amperage is important anywere from 37 to 62. no garentee that what is stamped on the case is true anymore check alternator against heater and running light draw it shuold kick up when you turn them on even at idle check all the conections for corrosion or resistance could even be in your wirring. the regulators need the air gap correct and the voltage properly set. the modififeid the regulators in 66 i have the update will post it. as far as the halogen go good move but the wiring cannot handle the stress. if you dont want to burn anything down wire two relays into your system the hot wire off your battery goes to them instead of your headlight switch all the swith will do now is turn the relay off on. im running 55w upper and 125w lower i tried 150w but they put too much stress on the electrical system

1965CS · Guru

Also had these and other issues, especially the annoying flicker at idle. The best solution for me was to upgrade and modernize with an alternator c/w built in regulator. No problems now.

65wagon · Poncho Master!

1965CS wrote:

Also had these and other issues, especially the annoying flicker at idle. The best solution for me was to upgrade and modernize with an alternator c/w built in regulator. No problems now.

that cheating weres the fun in tracking down those pesky gremlins, but even if you switch upgrade the relays your light switch will thank you for it

davelacourse · Poncho Master!

OK Todd with all the feasible flaws offered by your faithful flock, please inform us know how you finally fixed your flicker!

Dave

65Camino · Uber Guru

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