38 2dr sdn I hooked headlight switch directly to starter.. thot maybe voltage reg. was bad and spiking voltage but no change bulbs last about one day ..I also hooked a extra ground wire from bat to body of car still no change..is there a new replacement bulb that will hold up better ??sc

Make sure the sockets are clean and well grounded.

What is your voltage when the engine is running fast enough to charge? It should be around 7.5 volts with a battery in good shape.

What bulbs are you using? I bought a dozen Chinese repops and they would last about five seconds. I then got a bunch of NOS bulbs off of ebay and have had no problems.

Battery controls voltage more than the regulator..at the battery voltage should be 6.5 volts,(I have not measured it but will today at fast idle)remove battery and voltage will spike to 15+ volts,bulbs are old stock 1940's off ebay..I was thinking of going to halogen or something like that ,anyone have a idea ??

It should never spike to 15V.

Do you think that could be the problem?

Checked voltage today 6.5 volts at starter at fast idle ..voltage will never spike to 15 with battery hooked up only when cable is removed..I leaned this the hard way years ago with running car with lights on and then remove bat cable,

As a poor youngster who really didn't know any better and couldn't afford a new battery, I used a friends battery a few times to start my car then disconnected it & ran on the generator to get home. I never had that type of an issue. Until now I've never heard of it being normal for voltage to spike with the battery disconnected. That's what the voltage regulator is for, to regulate the voltage. I'll admit I'm not expert so I could very well be wrong but it's a new one on me and I would never consider that behavior to be "normal".

6.5 volts at the starter would indicate it was not charging.

Is it possible someone strapped a cut-out switch from a 37 to your generator? Believe me, they do not regulate the voltage.