Headlights are flickering and on hi beam cut out

[bobh67 18]

First night run with a recent redone 69 and my headlights are flickering somewhat on low beam (not cutting out completely).....On Hi beam after awhile they DID cut out completely, and came back on aftera short time.

I have a NEW dimmer switch and a NEW repro (import version) headlight switch already installed. I know there are no headlight ground wires Am I correct? Should I replace my new $30 repro headlight switch with the original $150 or so from NPD? Any thoughts? Ground? Headlight switch?

[Muletman 18]

The headlamps have ground wires, maybe one is loose. I have an aftermarket harness, it should be the same though.

[stangnet33 88]

What headlamps did you install ? Might have to add relays as the headlamp switch won't hold up to aftermarket halogens or anything that draws more than the classic sealed beam.

[bobh67 18]

Don't believe they are Halogens as I purchased them at NAPA and they don't say halogen anywhere on them......Also regarding the headlight ground I didn't think the '69's have a headlight ground wire ....I know that '70's do though. Can anyone confirm this too?

[69volunteer 84]

Both sides do.

 

Do a search on here for wiring diagram or send me a PM with your email and I will email you one.

[LoneWolf2U 136]

Did you lube the horn ring on the steering wheel?

Dry horn contacts will cause headlights to flicker and trip the headlamp breaker in the switch.

Simple test, turn on the lamps and slightly trun the steering wheel die to side and watch the lights.

[Raven R code 281]

What headlamps did you install ? Might have to add relays as the headlamp switch won't hold up to aftermarket halogens or anything that draws more than the classic sealed beam.

 

Ah!!!!....that may be why my headlights stopped working after installing halogens.....25 years ago. I still have the FoMoCo script headlights that came in my car too.

[ashleesmach1 28]

the headlight switch is bad

[Mike65 475]

X2 ^^^^^

[BinaryBo 10]

I had the same problem with a new switch (from Mustangs Unlimited) and halogen headlights. I purchased a BWD switch from Advanced Auto for about $24.00.

 

The front spacer bracket was incorrect so I had to drill it out and weld on the one from my old switch. A bit of a PITA, but it works fine now. I am guessing it is just a better made switch or has a higher rated breaker switch in it.

 

http://shop.advanceautoparts.com/p/bwd-headlight-switch-s404/5971098-P

 

Bo

[Kris 90]

Oreillys has the same BDW switch with the correct bell shaped space on it. Thats where I got mine and it has lifetime warranty.

[BinaryBo 10]

Oreillys has the same BDW switch with the correct bell shaped space on it. Thats where I got mine and it has lifetime warranty.

 

Really??? I went to Oreily's first and they said they couldn't help me. I see it on their web site now...

 

http://www.oreillyauto.com/site/c/detail/BWD0/S422/02006.oap?year=1969&make=Ford&model=Mustang&vi=1132401&ck=Search_headlight+switch_1132401_1363&keyword=headlight+switch

 

It is cheaper too. Are you running halogen headlights also?

[bobh67 18]

Does this O'Reilly's (very low price) switch work with halogen's? Anybody using this with them?

[bobh67 18]

I replaced the old switch with a BDW switch and replaced the lo beam headlights with OEM (non halogens). Now the headlights even on Hi mode Do NOT cut off.... BUT I still have a slight flickering.Could this be more of a charging issue ? I have a 100 amp new alternator and new voltage regulator. Could it be the alt or regulator?

[det0326 179]

I replaced the old switch with a BDW switch and replaced the lo beam headlights with OEM (non halogens). Now the headlights even on Hi mode Do NOT cut off.... BUT I still have a slight flickering.Could this be more of a charging issue ? I have a 100 amp new alternator and new voltage regulator. Could it be the alt or regulator?

Do you notice the flickering anytime or maybe at certain RPM's or just on idle? On bumpy roads but not on smooth roads? These kind of situations are hard to find sometimes I have chased these kind of problems before too. More times than not it is usually a loose or rusty connection some where.

Dave

[bobh67 18]

Idling in the shop with the headlight on the interior wall. Just looking at the wall I can see them fluctuating. Headlight ground is not the issue now. I took care of any concerns that would be.

[SA69mach 39]

I had similar problem with a 70 coupe when I bought it. Lights would dim and flicker a bit every time I pushed the clutch pedal in.

 

I hunted for a short or a stripped wire casing around the pedal. No luck.

 

Turns out the grounding was poor from body to engine. These old Mustangs need very good grounds from negative battery terminal to engine AND body, plus engine to chassis/body.

You need to check, clean, and if necessary, install good heavy ground cable to all three;

-ve batt terminal to body

-ve batt terminal to engine block

engine block to chassis/body/firewall

 

Over the years, the connections get corroded, weak or painted over. Headlight flickering is a good sign of poor grounds.

 

Best of luck

[bobh67 18]

The thing is all is new on this car. This is a fresh total restoration.25 miles on the whole car, every component. All wires are new and correct. All connections are scrapped to bare metal star washered and the new grounding bolts are tight.

[det0326 179]

The thing is all is new on this car. This is a fresh total restoration.25 miles on the whole car, every component. All wires are new and correct. All connections are scrapped to bare metal star washered and the new grounding bolts are tight.

 

Well it sure sounds like you did it right . Since the lights are flickering with

it idling in the shop I would say you may be right, it must be something in the charging system. You say too that all that is new . Are you running an external voltage regulator or is it built in with the alternator. Either way you can change the regulator the internal one is just a little more trouble.

IMO the regulator is the only thing left. You can actually check the voltage at the battery terminals, with the car idling and lights on and see if the voltage is fluctuating it could be possible that the fluctuation is so slight that the VOM would not show it but an oscilloscope sure would.

Dave

Edited June 4, 2014 by det0326

[bobh67 18]

External voltage regulator New from CJ pony. I could just switch the regulator with others I have to see what happens then. What do you think?

[LoneWolf2U 136]

Is your alt grounded within the charge harness and connected at both ends?

Lack of grounding will cause this condition.

[bobh67 18]

Yep ,The alt ground is grounded to the block, scraped clean of paint and star washered to bite and bolt tight on each end. Also new ground wire from the block to firewall again both ends there scraped and star washered to bite into metal and bolts are tight.

[LoneWolf2U 136]

Do you have the ground connected at the voltage reg?

[bobh67 18]

Yes I do I even took it back off and cleaned the clean terminal again Star washered it and tightened it good. So I think I will try a different voltage regulator here next?

[j69302 11]

does the dimming and flickering go away at say 1500 rpms or higher?