Headlights/Interior Lights Pulsing

[67_Vert]

Greetings all!

I just picked up a 67 convertible, fully resto'd and really the only thing I can find wrong with it is that the headlights and interior lights pulse when you bring the RPMs up a little. Any ideas on what might cause this? Alternator?

Thanks in advance!

BTW, you can see pics here if you want:

http://picasaweb.google.com/bdillon08/Mustang

 

[Rusty67]

Could be a couple of things. If you can check the voltage at the battery while it happens that would tell you if its the alternator. Just have a friend rev it for you. Also, it could be that the headlight switch itself is going bad and the vibration from the engine is causing it to short intermitently.

 

[TOM B]

Most if not all older mustangs will do this because of the low 60 amp alternator and regulator, upgrade to a one wire 100 amp alternator and get rid of all your troubles.

 

[tretz]

cured mine with a new light switch

 

[65fastbackresto]

Mine does it too

I thought it was normal....

 

[66HertzClone]

Look for the ground strap between the rear of the right side cylinder head and the firewall. Often missing, this pesky little thing can cause the symptoms you describe, to make sure the strap will help, place a jumper cable between the block and a hefty bolt on the chassis. The original point type style voltage regulator can sometimes cause this, a new replacement using an electronic style is a good inexpensive improvement.

 

[justford]

The electronic voltage regulator cured my problems with the lights.

 

[67_Vert]

The electronic voltage regulator cured my problems with the lights.

Which one did you use?

My switch is also bad, the potentiometer doesn't seem to work. As I turn it to the right to dim the interior lights, the lights flicker on and off.

I will replace both, I just need a recommendation on which voltage regulator to use.

 

[ForceFed70]

My car did the same thing. It was either the voltage regulator or the alternator, I replaced both and it fixed my problem. It had nothing to do with the alternator being too small....