I'm having Headlight and Wiper Door Problems

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Sep 8, 2004 | 08:48 AM

Mr D.

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From: Huntsville AL

I'm having Headlight and Wiper Door Problems

I spent about 12 hours yesterday testing / op checking every electrical and Vacuum system on my 1969 project in preparation of installing the interior. Everything works except for 2 problems.

1. The headlights go from closed to open and back to closed when vacuum is applied to the system.

2. The wiper door just will not open and close using the wiper switch or manual override switch (I can make it work using hand vac pump on the coffee can).

I have tested every valve and switch in the headlight and wiper system and both relay valves are the only parts that tested bad as per the testing instructions (vacuum on yellow port while blocking off green port does not hold vacuum). Both work when vacuum is applied to the top small port as far as moving the plunger up and down. I even had a used spare here and it tested bad also.

I know my system is tight as I'm using a air powered Vac Pump and system is holding 22 in hg. Could the relay valves cause the above problems? I would like to know for sure before I buy 2 new ones. On a side note, I'm 100% sure all the vacuum hoses are hooked up correctly. Thanks in advance for any insight on this.

Sep 8, 2004 | 08:57 AM

Eddie 70

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From: Lenoir City Tennessee

Ci 6, 8 & 10 Veteran

St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15

I had a problem with my hookup when I put it all back together also. I found that there was a problem with the diagram I was using. Seems like a connection on the headlight switch was reversed on the drawing I had been using. Sorry I don't know where I got my diagram right now, but it was off the internet. Someone on here told me of this and I tried it. I was opening the wiper door at all the wrong times and the headlights were coming open when I turned the wiper override on.

Sep 8, 2004 | 09:10 AM

Mr D.

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From: Huntsville AL

My headlights work fine with the headlight switch and override switch when the vacuum pump is running. once I turn the pump off and then back on thats when the headlights cycle up and down.

Sep 8, 2004 | 10:10 AM

CGGorman

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From: Smile, it's just the internet.

Regardless of whether on not the relays are causing your problem (though they probably ARE), you're going to need to either fix or replace your relays. You know they are bad, so I'm not sure why your asking...

Sep 8, 2004 | 10:38 AM

Jack71

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From: Boxford Mass

Both relays are bad with the same problem? That sounds odd, but then again anything can happen with corvette vacuum systems.

How much vacuum is your engine pulling? Less vacuum is probably the cause of the wiper door problem. It would be interesting to put a vac gauge on the control hose to a headlight relay and see if you get an initial flucuation when vacuum is introduded.