With car on and headlight switch off im getting 8psi and when i turn on drops to 0


Yellow hoses has 6psi on both


Using the diagram i did trouble shooting if i remove one yellow hose at a time and block it off the opposite light will open and close is my canister not good thanks in advance i can make a video if u guys want

 

Headlamp switch issue ? What year is the car

 

 

Switch is new about 1 month old i bought off amazon from willcox account after making the video now my left side will go down sometime by itself with out blocking it off

 

It sounds like your car has a performance cam in it. This will give a low manifold vacuum, which doesn't mean the headlight system won't work, but it may be more susceptible to small leaks since it doesn't have the extra capacity to deal with them.

When you plug the yellow hose, you're removing that light actuator from the circuit. Since one or the other works, but not both, I would suspect both light actuator seals are leaking just enough that the system cannot overcome them together. The actuator seals are located only on the shaft side of the actuator (green line).

One way to check would be to put the switch in the open position and manually open the headlights. Then close the switch and see if the headlights close. If the headlights don't close, then your actuators themselves may be bad. They are expensive and I would certainly check each one with a vacuum pump before replacing them. Replacement seals are available from on-line vendors and are easy to replace.

Good luck and I hope this helps.

MajD

 

OK.

!.) You MUST check your vacuum check valve that is attached to the hose coming off your intake vacuum supply fitting. It MUST be good...so...vacuum can be stored in your storage tank in the front of the car.

2.) Knowing that when you remove the yellow hose and the other side works...remove BOTH yellow hoses and plug them. Then..when the engine is running and you have your headlight switch OFF (or pushed in)...pull the small vacuum hose on one of your actuator relays and see if you have vacuum there. It MUST have vacuum on it.

Then....pull the headlight switch to ON and check this hose again and there should be NO vacuum on it.

If both of these checks are correct....your headlight switch is GOOD.

3.) This will allow you to check and verify IF the replaceable seals in the actuator are good or not. Remove the red and green strip hoses from ONE of your actuator relays. While lifting up on your headlight door so it is open half way...and you can manually raise it and lower it. Take your thumb and cap of one of the hoses., and see if when you try to move the door if you feel resistance. IF you do while pressing down or lifting up..then slowly let your thumb off an then cap it again and this will let you know that that seal is ok. Then do the other hose the same way. Your actuator pod is good if when you press down or lift up on the headlight door and feel it fight you.

If both actuator pods are OK...then connect all the hoses back on the relays. When the engine is running...take hose and place it a the squared bottom portion of the relay and listen for a vacuum hissing sound. IF you do...then the relay(s) is/are shot.

IF you capped off the RED hose and you can lift up and push down on the headlight door when the hose is capped off...the actuator is BAD because the internal seal is ruptured and you can not replace that seal.

DUB

 

Anytime you are having vacuum "issues", the first thing you MUST do is determine your engine's baseline vacuum level. This is the vacuum level your engine attains at idle with all vacuum accessories eliminated from the system. So, you need to disconnect ALL vacuum lines going to the various vacuum operated systems (headlamp doors, wiper door, HVAC/heater system, etc.), cap off any open fittings, and THEN check the vacuum level at idle.

Yours shows 8" Hg with all the stuff connected and much less than that with some time turned ON. If you do the "baseline vacuum" check, I would guess that you will have over 10" Hg, even if you have some wild cam in the engine. If you don't, it will check somewhere between 12"Hg to 17"Hg....more than enough to work your vacuum systems

If this proves to be true, then there are leak paths in the systems you have connected. How do you find them? After doing the baseline test, you re-connect each system one-at-a-time to find which systems will LOSE vacuum. Any system that loses more than 1"Hg is a leaking system and the leaks must be found and resolved. Follow that process thru each system and you will have fixed your problems.

 

at the main


Smaller hose which goes to tee in front pressure measure same

 

bigger hose off filter

big hose that goes to canister pressure same but the 2 yellow hose that come off pressure is only half so is my canister no good and now i hear a small heis from below

 

When Trouble Shooting Vacuum problems I can guarantee that the problem is a Vacuum leak ! So its just a matter of finding it. The best way is to listen for it, but You can't hear it with the engine running. So run a long hose from another Vacuum pump or Car sitting out in the driveway wile Your car is in the shop. Now You can hear it leak. This will also let You know if Your Engine Vacuum is enough.

 

Is your ballast a large bar located in front of the car? If so, I believe the vacuum line attachment points are brass nipples that screw into the ballast. Perhaps one of those has started leaking. It can't hurt to take them out and put some thread sealant on them.

MajD

 

Its a large can with 3 nipple if i move canister vac line to the control it will open and close can i delete the canister and run a t

 

Interesting...I'm assuming you have the cannister that looks like a coffee can. I'm not sure which line you're removing but the cannister should be hollow. If by-passing it causes the system to work, that tells me there is a leak in the cannister.

The cannister is a buffer of sorts that helps the system deal with fluctuations in vacuum caused by enginer RPM, loading, and other causes. You could by-pass the cannister, but the systems may behave differently under certain conditions. For example, your headlights may open slowly at high RPM, when manifold vacuum is generally low.

MajD

 

It is not wise to remove/by-pass/delete the vacuum storage canister because you need it to store the vacuum in the system....because like it was written in the above post from 'MajD'...it will perform differently.

And this can also effect your HVAC vacuum system also.

But it is your car and you can do what you want.

DUB

 

Instead of pulling random hoses off to see what happens, use this guide and go step by step and you will find the problem faster and without buying or changing parts that are working.



http://www.corvette-101.com/vacuum.htm

 

Yes i have the coffe can type all signs piint to canister 17 psi goin in and 6 comin out the lights will open and close if i plug one of the 2 yellow lines comin off canister. Plug one side opposite opens look at video and look at diagram the bigger line off filter goes to canister

 

With the car idling, take a clamp and pinch one of the yellow lines and put your vacuum gauge on the other yellow line, or nipple. Take a second clamp and pinch the supply line and watch the gauge. If the vacuum bleeds off fairly quickly, then the cannister is leaking.

The behavior of the headlights seems weird, but perhaps the vacuum is low enough to only operate one actuator at a time. Maybe there is a different problem causing it. Before you figure that out, you have to eliminate or confirm the cannister as a problem.

MajD

 

Maj d
Started car put pressure gauge one one yellow and clamped other yellow had a rough 10 then i clamped main as soon as i clamped the main pressure went out so bad canister

 

I guess increase in vacuum when one headlight was removed was enough to activate the remaining headlight. Hopefully replacing the cannister fixes all your vacuum problems.

MajD

 

THIS CAN HAPPEN. I have seen/experienced it countless times.

DUB