69 charger-how i fixed the vacuum headlight switch dohicky:)

[69chargeryeehaa]

I just rebuilt my headlight vacuum switch for the hide-away headlights. It was actually really easy to rebuild the switch, the most work was getting it out of the car, that fun underdash work we all love.

My original problem was this: if i start the car with the headlights in the off position, i hear a hiss of vacuum at the switch in the dash, sometimes after about a minute it stops and then if i turn on the lights the doors open. lately the hissing does'nt stop and when i turn on the lights the headlight doors don't open no matter how long i wait. all the vacuum lines are new, the canister is ok and i pressure tested it, the switch arm is there and conected properly. if i hook up vacuum to the "T" fitting at the front the headlights open and close fast. from the switch when it does work they open slow.

here is how i rebuilt the switch:

first i made sure that all the vacuum lines were ok and had no holes, i disconnected the vacuum head connector from the switch and hooked up a vacuum guage to the hoses and sucked on them and made sure it all held vacuum. also i found there is a one way valve in the vacuum accumulator canistor, if you hook up a vacuum guage to one connection and suck on the other, when u stop sucking on it and the vacuum guage holds vacuum then that connector hooked up to the vacuum guage is the one that connects to the vac line going to the dash. that way when you shut off the car the system still holds vacuum to close the lights with the car off. next the fun part, unbolt the vacuum switch from the back of the headlight switch. there are 3 screws. next there are little "tabs" that hold on the cover of the slider, the part that moves with the headlight switch, i broke off the tabs with some needle nose pliers, and noticed that there is a little peice of spring steel that pushes a rubber block with a channel that re-directs vacuum to either hose to open and close the light covers. that spring steel was broken on mine, giving it no pressure to seal properly. then i drilled under the tabs with a 1/16" bit on my drill press, and used small screws to screw the cover back on making the unit servicable. the funny part is that the cover originally looks like it was ment to be screwed on cause the holes in the cover are counter sunk/taperd for a counter sink screw. then the important part was to pack the whole thing with white lithium grease, the grease acts as a "sealant" with the rubber block. i made a sring plate from a small peice of clear "pop bottle like" plastic from a little container that was from #11 exacto-knife blades. before you take yours apart, push the slider into the unit and see if there is any spring action in it, if it's ok, then the unit could eaisly be fixed by packing it with white lithium grease thru the opening on either side when you move the slider. mine was full of dirt, and the spring was broken in half. no wonder it did'nt work!!!! my headlights would take over a minute to open when they felt like working 50% of the time, now they both open within about 5 secconds, big improvement!! at least now i don't have to get out of the car and open them manually!!!!

here is a pic i drew in paint to illustrate the internals of the vac switch:

[69chargeryeehaa]

another pic:

[cobradriver]

dude that info was huge.....my switch is pretty much exactly what yours is....its not sealing back there , i can hear the hissing...lol...well now i have my marching orders.....fix da switch....

[Animal]

Thats a clever peice of engineering.Anyway,I got a brand new one in original box off ebay. .Sorry I couldn't resist that one.Honestly that is a great fix,considering my one cost nearly $200.00..Well done.
Adam

[Animal]

Also,you wouldn't happen to be THAT guy would you.

[69chargeryeehaa]

Also,you wouldn't happen to be THAT guy would you.

SHHHHHHHHHH, or else "they" will know.  u know "they" don't u???

[resq302]

Thanks for the info on the fix.  My head light doors would open but not close.  This ended up being the problem.  I pulled mine apart and was in good condition interally wise with the spring steel.  Like yours, there was a lot of dirt in there which I assume clogged the one port for closing the lights.  Before, they took forver to open, now, they close really fast.  I do notice a slight hiss but if I wiggle the headlight switch, it goes away.  Might just need to be operated more to get the lithium dielectric grease moved around.  Thanks again for the fix.

[69chargeryeehaa]

    glad to help.

[Dennis K]

Thanks for the info. I remember reading this a long time ago, and I probably need to do the same thing to my 68, since the headlight doors were starting to get a little sluggish. I found a pinhole in the vacuum can and fixed that, but I don't know if that was 100% of the problem. Another idea I had was to bypass the factory mechanical vacuum switch and use some electrically operated solenoid valves that I found on an old early 80s Ford I found in a junkyard. I was thinking I could hook them up to the headlight circuit somehow, and then we Charger guys could use regular B-body headlight switches without the vacuum switch arm on them. I don't know how or if I'm going to get it to work, I just thought I would share the idea because there are guys here who are a lot smarter than me and could probably figure out how to make it work and tell us all. If I had one solenoid valve that was normally open and one that was normally closed, it would be easy.

[70 Charger RT]

This is a great thead.  Learn something everyday from this site.

[mopar67]

 

[69chargeryeehaa]

 

[70charger_boy]

hey 69chargeryeehaa do you still have your charger, or did you sell?

[69chargeryeehaa]

hey 69chargeryeehaa do you still have your charger, or did you sell?

I sold it , ironically i'm flying out tommorrow to the US to pick up a 69 charger r/t    

[70charger_boy]

good luck man