Question: Headlights won't raise.

[rgtrough]

Hey guys, long time no posting. 1974 coupe headlights come on but do not raise. I vacuum problem. How to trouble shoot switch without removing dash? Car is running great. No signs of vacuum leak. Plugged/broken check valve?
Thanks for any helpful information.

 

[frank_nesta]

QUOTE=rgtrough;1126648]Hey guys, long time no posting. 1974 coupe headlights come on but do not raise. I vacuum problem. How to trouble shoot switch without removing dash? Car is running great. No signs of vacuum leak. Plugged/broken check valve?
Thanks for any helpful information.[/QUOTE]

I suggest using the Diagram From Wilcox Corvette. Page 5 is for a 1974.

http://willcoxcorvette.com/repairandinstallhelp.php?hID=218[

To trouble shoot the switch without removing the switch. I would first check the headlight Manual Override switch just under the steering column and above the brake pedal. Pull it down to see if it opens the headlights. If it does then it is the headlight switch. You could also take the vacuum line with the white strip coming from the headlights and connect it to manifold vacuum. If the headlights open then it is the headlight switch. Good luck.

 

[6880 Mike]

Check the main vacuum supply line beginning with the fitting on the intake manifold. Start there and work you way along.

 

[frank_nesta]

Hey guys, long time no posting. 1974 coupe headlights come on but do not raise. I vacuum problem. How to trouble shoot switch without removing dash? Car is running great. No signs of vacuum leak. Plugged/broken check valve?
Thanks for any helpful information.

Bud,
Any luck?????

 

[rgtrough]

Hey guys, thanks for the quick replies. I have not had the chance to trouble shoot this problem, maye tomorrow. The manual override switch intrigues me. I didn't know such a device existed. I will post my findings

 

[rgtrough]

Hey Frank, used the diagram to trace the vacuum lines and found one broken on the driver side actuator. Thanks for your help.