ettevroccorvette

I am working on my buddies 74 corvette (c3) and we have a concern. The headlights go up at the same time in the first try but if you pull the headlight switch the second time right after the previous pull,the driver side head light goes up and the passenger head light delays 3 seconds and then goes up.Is this normal???

Scottys78

Very normal

Alan 71

Hi ette,
Sorry to disagree but it's not 'normal'.
If the engine is running they should continue to open and close in unison.
If the right side doesn't move for 3 seconds, and then opens quickly, it's likely a problem with the relay for that actuator. (1 or 2 relays in 74?)
If it begins to open immediately, but opens slowly, it's likely a problem with a leak in the 'open' side of the actuator.
Also check that the vacuum reservoir tank doesn't have a leak.
Regards,
Alan

MrJlr

OK...not "normal".....but common

Scottys78

Perhaps that is a better way of saying it. I see this all the time with C3 headlights

Swamppro

My 74 does the exact thing.

BBCorv70

Does it behave this way if you open the head lights, then close and wait 30 seconds or more before reopening? If waiting helps I'd suspect you have a vacuum leak, taking more time for the vacuum reservoir (tank) to replenish. I found I had several leaks on my 70, most were from the vacuum relays. To find them I used a hand held vacuum pump with a gauge to test for leaks at the various components. After replacing the three vacuum relays (70 has three) my headlights became very responsive. Hope this helps.

ettevroccorvette

Thanks for your quick reply

ettevroccorvette

Thanks for your reply. I will check for any leaks

ettevroccorvette

i replaced both relay valves and both headlight actuators and there hoses.

kcb37

I have had mine for about 6 months, 74 also.
But my headlights have never come up together. Always close. D/S up P/S right behind, or D/S half up P/S starting.

CVO2FIXUP

How do you make your headlights stay up to work on them with out the head lights being on or the engine running.

Iceaxe

On my 70 the passenger side headlight is always 5 second behind the drivers side. One day I'll get around to replacing the relay, or not.

doorgunner

ettevroccorvette!

Do you realize the second half of your Username is written backwards?

(Yes.....I have dyslexia.....LoL)

Hang in there.....you'll solve all the problems.

76CSRvette

I saw the name and didn't catch it I was still trying to pronounce it
But I consider it normal at least on my rig but I don't care to fix it as im looking for the perfect lights to use as FIXED lights

BBCorv70

Did that solve your problem? If not I'd guess you have other leaks. I tracked mine down using a handheld vacuum pump with a gauge, used for bleeding brakes. I isolated portions of the plumbing by pinching off the hose, see if it could hold a vacuum. Moved down the line until I found a section which leaked. Could be a leaky vacuum tank?