Understanding headlight vacuum lines

[myk]

I'm just trying to make sure that I have the routing and lines correct in my head as I try to sort out my headlight door issues; I've been staring at the FSM page showing the routing but I need more detail.

From the headlight switch:
1. The top, yellow striped vacuum line goes to the top port on the door actuator, with a t-fitting to go to the passenger side.
2. The middle, green striped vacuum line goes to the vacuum canister.
3. The lower, unmarked striped vacuum line goes to the bottom port on the door actuator, with a t-fitting to go to the passenger side.

Now, I'm sure there's a second vacuum port on the canister, so that goes back to the engine for the vacuum source?  What if I wanted to bypass the vacuum canister; how would I go about doing that-just connect the two lines going into the canister together?  

I hooked up a vacuum pump to my headlight actuators to see if they work.  The left one goes up and down, but the right one won't go down-am I missing something here or could the actuator be damaged?  Thanks in advance guys...

[resq302]

Without confirming it by looking at y car, I am pretty sure you are correct.

[A383Wing]

actuator could have a hole in it....you can by-pass the canister, but you would have to have engine running to operate the headlight doors

[myk]

..............Question guys:

If there's a leak of some sort, anywhere in the headlight door vacuum system, be it in the lines, canister, actuators-wherever; could it affect the engine and/or the driveability of the car?

[A383Wing]

yes.....it's a vacuum leak...engines don't like those

[myk]

yes.....it's a vacuum leak...engines don't like those

My God man, are you serious?  I've had this hesitation/off-idle bog for the longest time now: http://www.dodgecharger.com/forum/index.php/topic,104129.0.html.

This afternoon, when I got the "bad news" about my headlight door system needing some work (leaking canister, bad lines, bad actuators, etc), I told them just to cap everything off and I'd deal with it later.  Well you know what, my decades long hesitation is about 90% GONE...

[Mopar Nut]

 

[myk]

Yup, spent the night driving the car all over town with dead headlight doors but a throttle response I haven't felt since I bought the car.  I never would've guessed it.  In any case, I probably won't fix the vacuum system; I've got an option for electric motors and I'd rather just have it that way...

[A383Wing]

well, now that you have capped of probably all of the vacuum leaks on yer engine, it's time to go back and re-adjust the carb correctly because before you had adjusted it to compensate for the extra air that was going into the engine when it was not supposed to

[myk]

well, now that you have capped of probably all of the vacuum leaks on yer engine, it's time to go back and re-adjust the carb correctly because before you had adjusted it to compensate for the extra air that was going into the engine when it was not supposed to

Right.  The car is probably running......too rich?  Will my timing need to be adjusted as well?  I know my idle speed dropped for some reason, unless the 'tech did that and didn't tell me about it...

[A383Wing]

yer timing should still be the same...yes, the idle probably would have dropped, and now it's probably running a little bit rich

[bull]

yes.....it's a vacuum leak...engines don't like those

My God man, are you serious? 

[myk]

yes.....it's a vacuum leak...engines don't like those

My God man, are you serious?  

Lol, man in all of these years I never thought the headlight door system could directly affect the engine.  I've sprayed so much 'carb cleaner around all of the usual vacuum leak sites trying to find leaks that I'm shocked there's any dirt in my engine bay at all.  I'm rejoicing that I don't have to walk the car off the line anymore and pray that I catch up to the Nissan Leaf that just blew me away.

Thanks a million guys!

[Bob T]

The sound of the penny dropping over here too Myk! 
It sounds similar to a dropoff in performance issue on my car, guess I'd better start checking perished vac lines, I did a few when I got it but not them all. The can doesn't hold enough charge to close them when the motor is shut down either.

[myk]

If I resurrect the vacuum system for the headlight doors I'm bypassing the can-I don't see how I need it, and it just represents another possible vacuum leak to contend with...

[Dino]

Nissan Leaf??  Okay, you need to install some cherry bombs so at least it sounds fast.   

Unless you're going to electric, you can't bypass the can as you need a reservoir for the system to work.  To be honest it's a very simple but effective system as is, but yeah there cannot be any leaks, in any vacuum system, anywhere. 

[myk]

I thought there were some guys in here that bypassed the can?    I need to go back and re-read those threads.  Nevertheless, eventually I'm going to have a motor system installed-it's just better with motors IMO...

[A383Wing]

If I resurrect the vacuum system for the headlight doors I'm bypassing the can-I don't see how I need it, and it just represents another possible vacuum leak to contend with...

if you want to by-pass the can, that's fine...just couple the 2 hoses off the can together....just remember, you will have to have the engine running to operate the headlight doors open & close

Bryan

[resq302]

I think the reservoir can was for two reasons.  First was to act as a buffer so the high vacuum demand wouldn't open / close the headlight doors too fast and cause a slamming action.  Secondly was to provide a reservoir to be able to close the headlight doors if the engine was shut off prior to turning the headlights off.

[A383Wing]

the can is gonna hold whatever the highest engine vacuum was when it was running.....bypassing the can will not make the doors "slam" when connected to intake manifold vacuum.

And yes, the reason for the can is so you can open & close doors without engine running....but maybe only 2 or 3 times

Bryan

[Dino]

the can is gonna hold whatever the highest engine vacuum was when it was running.....bypassing the can will not make the doors "slam" when connected to intake manifold vacuum.

And yes, the reason for the can is so you can open & close doors without engine running....but maybe only 2 or 3 times

Bryan

3 on mine but only the ps closed on the last try, lazy ds door...   

[1974dodgecharger]

Can I connect the PCV line to the canister build pressure that way?  My carb does not have a vacuum line (race carb) only a vacuum testing port.  I do have a PCV off my valve cover and 3ft of tubing from there I was gonna hook it to the canister and hopefully that buils pressure enough to open the lights.

[fy469rtse]

Or you can do away with the vacuum and get the kit from charger specialitys and convert doors to electric , plugs in head light harness for similar operation

[Ghoste]

Ah man, that's cheatin'. 
Besides, the vacuum setup is kind of cool.

[Fred]

Ah man, that's cheatin'. 
Besides, the vacuum setup is kind of cool.