When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Sorting out the bugs in a '69 convert (84K miles) I bought in April, and guess what? The headlights don't function properly...what a surprise. The pass. side comes up, but not immediately; the driver's side rises several minutes later, and I have to reach under the grill to lower them.
A couple of questions before I go digging into the hoses:
- Since the units do go up, could the hoses be somewhat intact?
- What are these two connectors for (see photos)? There are two wires that apparently broke off from the pass. side one; the driver's side one has wires, but is just hanging there with no visible place to connect. Passenger side: 2 Broken wires; BLACK and YELLOW Driver's side: Same connector; no place to plug it in
.
Last edited by mh_merc; Jul 28, 2021 at 07:00 PM.
Reason: adding text; spelling
The 2 connectors are for your position sensors which will light up when you turn your headlights on if they have not locked into position correctly. You are missing the sensor switch on the right side.
Sorry can't help you with the first question.
Wrt to the switches I just reported a similar problem. I could not find new connectors but a CF member is sending me a couple of used. If you are unable to locate any read my short thread. Another member suggested spade connectors. That will work if all else fails.
To comment on the Peterbuilt link - your 69, like mine has a brass vacuum tank next to the brake master cylinder and under the fender. The link describes a later year car with a different tank in a different place..
I haven't read the link but all those other parts seem to be pictured correctly, just maybe a little differently placed..
You should determine the tank integrity by blocking off the ports and do a leak down test. This is a reservoir with enough reserve to power the lights and the wiper door, provided it doesn't leak.
Also check the motor itself for vacuum. The intake manifold vacuum by itself isn't a good enough source to "pop" the headlights up quickly, hence the vacuum tank.
Pulling the tank is a pain, you have to drop the master cylinder to get it out. Being brass it can be soldered. I think those are rare pieces by now so repair is your best option.The link suggests putting vice grips on various hoses to block them off. I wouldn't do that to 50 year old hoses.
To comment on the Peterbuilt link - your 69, like mine has a brass vacuum tank next to the brake master cylinder and under the fender. The link describes a later year car with a different tank in a different place..
I must have a later car; the tank is on the right side.
Since you seem to be fairly new here, let me be the first, maybe, to welcome you. A lot of smart experienced people here.
Yep...pretty new. This thing is a lot more complicated than the '59 I had back in the '80s! Thanks, everyone for the welcome all the current and future help...much appreciated.
Looks like somebody's gone through your engine compartment rather nicely. I think you are showing me the actuator for the wiper door. Here's the vacuum tank
Vacuum system is relatively simple: tubing, tank, switches, valves....engine produces the vacuum when running. Most common headlamp system fault is the vacuum relays (all they do is 'switch' vacuum from reservoir tank to either side of the large actuator servo (one side is UP, other side is DOWN). As mentioned....not complicated.
Make sure vacuum 'devices' work as intended; get rid of leakages. Then everything works. Diagnose with a simple vacuum gauge using engine vacuum or generate 'test' vacuum with a hand operated vacuum pump (Mity-Vac).
Welcome to the Forum!
Looks like somebody's gone through your engine compartment rather nicely. I think you are showing me the actuator for the wiper door. Here's the vacuum tank
DAMN...I had to look pretty hard to find it!
The previous owner did put a ton of $$$ into the car a while ago; he brought it up to a very nice "driver" level. I'm not worried about 100% correctness (especially since the color's been changed), but I would like to have all the systems functioning.
Your main task would be to familiarize yourself with the 'normal' configuration of the 1973 engine compartment. The AIM (Assembly Instruction Manual) for 1973 is invaluable for seeing how the Corvette Assembly Plant put it together. (drawings, not photos) You also need a copy of the Chevrolet Chassis Service Manual; and if you will be rebuilding any components, the Chevrolet Chassis Overhaul Manual. Know how things are supposed to go together. You don't have to do it exactly like the factory, but stuff needs to work like intended.
the headlights are slow. hoses are plugged up. and the vent in the headlight relay is plugged up. i cleaned out my large long hose with a long truck oil dipstick. a fish tape would work. coat hanger. blow it out. don't suck to see if hose is clogged. bug nests are unpleasant.
To simplify your diagnostics you can try bypassing the storage tank to help diagnose the rest of the system. The tank allows reserve vacuum when the car is shut down and the system will work without it as long as the car is running and has good vacuum.
The other simple fix is if possible cut about a 1/2 inch from all the lines. The ends are usually stretched and poor fitting.
Ike
Last edited by general ike; Jul 29, 2021 at 10:18 AM.
C3 headlights
