The two relays at the front, they each control one headlight door. GM had just one there once and changed to two, we think it was so that if one fails you still have one headlight door working. To bypass one and use the other for both is really not "wrong", just not the OE setup. Other than the high cost, it makes sense to convert these to motor actuators, then eliminate all this vac hose stuff
It appeared that my car had 2 originally. Someone along the way switched to one. I wanted to make it back to original. Definitely when these go bad, I am going to convert to electric.
I'm about 6 months behind you on my 71 C3 resto, so I appreciate these videos. I also got the Vacuum line replacement kit and will replace most of the actuator units as well. I know it's kind of a weird system, but that's part of the charm.
I ended up replacing all my actuators and relays on both the wiper and headlight system. My lights work great, but I still cannot get my wiper door to function. C3 is my favorite year Vette.
@@timewiththedurbins I bought new actuators, but not the relays (yet). I suppose I should just get all new components, given the nature of the system. Did you check your tank?
You're real good patience I give you a lot of credit I got 1974 Corvette and I got go through the stuff you're going through it don't look like a lot of fun
Great review of the vacuum system! In my build I am going to do away with as much of it as I can. The '76 does not have the wiper door so only have to worry about the headlights. I am going to buy the electric motor swap kit for it. Great advice to run extra ground wires. I am getting ready to start the Painless wire harness install and will make sure I have plenty of grounds.
Not sure what's worse on these C3's, the electrical or the vacuum line stuff.....you're tackling the worse of the worse! Nice work. And yes, that middle knob under the dash is the wiper door override switch.
Thanks for the comments. For me the vacuum lines are easier than the electrical system on these cars. The wiring under the dash is a nightmare. It seems really crude for a production car.
wrong...left pull, headlight override...right pull, wiper door override...center rotating knob, wiper motor shut off...so many people on youtube and the corvette forum speaking out of their ass giving wrong information...gets tiresome
To clarify: For the wiper cover actuator: Red hose comes off the back and the green comes off the front (plunger side) yes? I know you went with an electric system, but hoping you recall…
Thanks. I replaced the complete units with new ones. I have done it both ways in the past. The main reason I replaced the complete units was because the old canisters were rusted pretty bad on the outside. I took the lazy way out and replaced them instead repairing them. You just have to remember to check the internal rubber bladder to make sure it is good before installing the new parts.
I ordered my kit from Ecklers but any good Corvette parts supply company should have them. I was having supply issues with Ecklers. I still have parts on backorder that I ordered in February. I started ordering a lot of stuff from Ebay and I usually get it within a week or 2. Good luck with your project.
Great video...I'm having an intermittent problem with my 71 Vette's headlights and wiper door. Some days I'll go out and both work fine and other times I try it an neither one works...they both break at the same time and correct themselves at the same time on other days. Any thoughts on that problem?...I tried the override switches under the steering column and they don't work either when the problem comes back.
Sounds like you have a vacuum leak but they are not normally intermittent. Does the car run rough when you are having the problem (another issue associated with a vacuum leak)? The believe the override switches would only be affected by a vacuum leak. I would check all your vacuum lines including the ones for the heater control and the automatic transmission line. That one gets overlooked sometimes.
@@timewiththedurbins Okay, thanks...after I did some more research, I'll probably replace the relay on the firewall that controls the wiper door and the headlights...shotgun troubleshooting for $40 ; )
On my 71 there is also 2 relays under the front of the car for the headlights and one on the passenger fender for the wiper door that is why I didn't think that was your problem because it was my understanding that both your wiper door and headlights would stop working at the same time. Check the check valve on the vacuum line that comes off your intake manifold. If you can blow through both sides it is bad.
The two relays at the front, they each control one headlight door. GM had just one there once and changed to two, we think it was so that if one fails you still have one headlight door working. To bypass one and use the other for both is really not "wrong", just not the OE setup. Other than the high cost, it makes sense to convert these to motor actuators, then eliminate all this vac hose stuff
It appeared that my car had 2 originally. Someone along the way switched to one. I wanted to make it back to original. Definitely when these go bad, I am going to convert to electric.
Best video I’ve seen on vac hose replacement/installation. Thank you!
Thanks for the kind words. I am learning as I go.
I'm about 6 months behind you on my 71 C3 resto, so I appreciate these videos. I also got the Vacuum line replacement kit and will replace most of the actuator units as well. I know it's kind of a weird system, but that's part of the charm.
I ended up replacing all my actuators and relays on both the wiper and headlight system. My lights work great, but I still cannot get my wiper door to function. C3 is my favorite year Vette.
@@timewiththedurbins I bought new actuators, but not the relays (yet). I suppose I should just get all new components, given the nature of the system. Did you check your tank?
After I installed the new parts, I checked the vacuum system with a smoke generator. The tank is good.
You're real good patience I give you a lot of credit I got 1974 Corvette and I got go through the stuff you're going through it don't look like a lot of fun
Thanks, if you like working on old cars you have to have patience. Good luck with your 74.
Great review of the vacuum system! In my build I am going to do away with as much of it as I can. The '76 does not have the wiper door so only have to worry about the headlights. I am going to buy the electric motor swap kit for it. Great advice to run extra ground wires. I am getting ready to start the Painless wire harness install and will make sure I have plenty of grounds.
The ground wires are definitely a weak point on C3 corvettes. Thanks for the comments.
Excellent explanation for this job!
Thanks.
Not sure what's worse on these C3's, the electrical or the vacuum line stuff.....you're tackling the worse of the worse! Nice work. And yes, that middle knob under the dash is the wiper door override switch.
Thanks for the comments. For me the vacuum lines are easier than the electrical system on these cars. The wiring under the dash is a nightmare. It seems really crude for a production car.
wrong...left pull, headlight override...right pull, wiper door override...center rotating knob, wiper motor shut off...so many people on youtube and the corvette forum speaking out of their ass giving wrong information...gets tiresome
To clarify: For the wiper cover actuator: Red hose comes off the back and the green comes off the front (plunger side) yes?
I know you went with an electric system, but hoping you recall…
The green attaches to the side towards the firewall and the red attaches to the side towards the radiator. I will email you the vacuum diagram.
@@timewiththedurbins Thanks. I got a diagram from Wilcox. My AIM shows it switched (Green off the engine-side) so I wasn’t sure.
Great Video, So you did end up replacing the headlights actuators instead of rebuilding them with the kit ? If so for what reason ? Thanks
Thanks. I replaced the complete units with new ones. I have done it both ways in the past. The main reason I replaced the complete units was because the old canisters were rusted pretty bad on the outside. I took the lazy way out and replaced them instead repairing them.
You just have to remember to check the internal rubber bladder to make sure it is good before installing the new parts.
Who did you order the vacuum kit from? Excellent video ! Im working on a 1982 with crossfire injection. Think I have vacuum issues! Thanks
I ordered my kit from Ecklers but any good Corvette parts supply company should have them. I was having supply issues with Ecklers. I still have parts on backorder that I ordered in February. I started ordering a lot of stuff from Ebay and I usually get it within a week or 2. Good luck with your project.
Great video...I'm having an intermittent problem with my 71 Vette's headlights and wiper door. Some days I'll go out and both work fine and other times I try it an neither one works...they both break at the same time and correct themselves at the same time on other days. Any thoughts on that problem?...I tried the override switches under the steering column and they don't work either when the problem comes back.
Sounds like you have a vacuum leak but they are not normally intermittent. Does the car run rough when you are having the problem (another issue associated with a vacuum leak)? The believe the override switches would only be affected by a vacuum leak. I would check all your vacuum lines including the ones for the heater control and the automatic transmission line. That one gets overlooked sometimes.
@@timewiththedurbins Okay, thanks...after I did some more research, I'll probably replace the relay on the firewall that controls the wiper door and the headlights...shotgun troubleshooting for $40 ; )
On my 71 there is also 2 relays under the front of the car for the headlights and one on the passenger fender for the wiper door that is why I didn't think that was your problem because it was my understanding that both your wiper door and headlights would stop working at the same time. Check the check valve on the vacuum line that comes off your intake manifold. If you can blow through both sides it is bad.
Where did you buy your vacuum hose kit from?
I purchased my vacuum hose kit from Ecklers. Thanks for watching and have a great day.
Hi - Are you open to consultation? I have a 71 project similar to yours and have some specific questions. Is there a way to email or DM you?
my email is mdurbin57@hotmail.com
@@timewiththedurbins Great - I’ll reach out this week. (Kalani)
brevity
Ok, I guess