BarretHC1

Hey guys, soooooo, over the winter I had pulled the dash, ansent out the speedo and tach for an overhaul. This was in response to a busted 1st and 2nd worm gear in my speedo head that worked the odometer. I bought replacement parts, and tried to fix, and 'magnetize' myself using an earth magnet. Everything I tried was a 'no go', and in defeat, I said forget it, and sent it out. It came back, and I re-installed everyone, and what a b*tch.... Ugh, worse going back in then coming out. ANYWAY, once I dropped the steering column, got the dash pad in, and cut up my hands laying on my back working all those stupid lights in place (converted to LED because I am not doing this again... EVER) the vehicle was operational again! woohoooo. But Iv'e noticed a couple of things that I previously hadn't. Maybe a coincidence, or maybe not.

1. My brake light is on. I believe it is my distribution block because when I unplug the green wire from the alt that goes to it, the light goes off. How do I fix this? Pull the whole thing out and clean it? Will I have to bleed something afterwards? I've never done brake work on my own, so I do not own bleeding equipment.

2. My headlight switch. The blue vacuum tubing, does it go to the nipple closer to the driver, or the nipple closer to the windshield? I am having an issue where I pull the switch out half way (to the parking light setting), and the headlight doors open up. The lights don't come on, but the open. Then when I pull the switch all the way, the doors stay open, and the bulbs come on. the override works as it should when the switch is off.... Must be a vacuum issue right?

3. I noticed that when I move my HVAC control from 'air' to 'off', if the sliding fan control switch is slid over, the fan will blow, even wit the left HVAC wheel off... It's not supposed to be like this right? OFF, and COLD but sliding the fan switch over on the top, turns the blower on?

Thanks guys, I know this point was literally all over the place, but now I am paranoid that something I did with the drivers dash pad, and wiring harness and vacuum lines, and everything else is screwing me up....

Also, on a diff topic, could you guys give me some pros and cons about ported vacuum vs manifold (full) vacuum..

THANKS!!! :-D

BarretHC1

I know I didn't get any replies but wanted to follow up incase this happens to anyone else. I could not reset the distribution block/proportioning valve (whatever you want to call it), so I am bringing it to my vette guy who is going to try and get it by aggressively bleeding the brakes. I will let ya'll know if that does it, or if I have to replace it (what a pita that'll be). Iv'e already pressure bled them but to no avail.

I am going to just replace the headlight switch as it's tubing is routed correctly, but still opening the lights (thus losing vacuum) when I turn on the running lights (one click of the pull out switch). We'll see if that works....

And finally, I did some research and some people are saying the blower fan runs constantly, even with the left HVAC wheel in the off because of a CO requirement? Someone said that was only for 1977 and up, but it makes sense for most C3 model years considering the fan switch has no off setting.....

Anyway, that's what I know so far!

suprspooky

The Brake Light Switch is probably stuck due to crud, it should return to center when you push hard on the pedal.

Your ported vs. manifold vac. question depends on your goals. (I'm assuming the question is relating to Dist. Vac Advance) Ported is mostly related to factory emissions and possibly part throttle/cruise fuel economy and is dependent on throttle blade position and the design location of the port in the bore (the centrifugal cams would also be part of the design consideration for emissions). Manifold vac is more often used for max performance tuning, it reflects engine loading better than ported. If you are street driving and want the best performance and part throttle cruise economy, go with manifold vac. I'd only do ported if you need to meet emissions or show judging requires it. No Vac. Adv. is for racing in my opinion.

Peterbuilt

#1 the 'BRAKE' light in the dash will go ON if the parking brake handle is UP and will (or should) go OFF with the handle DOWN.
The same dash light will go ON if there is a problem with the brake system.
Pull the BROWN wire off of the proportioning valve and see if the light goes OFF.

#2 Headlight vacuum wires:

BarretHC1

Yea, light went off when I pulled the brown wire. Ordered a new block, and a couple of ss brake lines that were casualties of removing the old proportioning block.
Now, that diagram... Is it right? lol I have seen different ones floating around, and right now I have the line coming from vacuum closest to the pull switch. I have the lt blue line going to override closest to engine. The problem is, there are way too many diagrams floating around with contradictory information!!!!

Peterbuilt

Yes! The diagram is correct.
With the headlight switch and override install correctly in the car the 'BLUE' line goes from the BACK of the headlight switch to the BOTTOM port of the override switch.

Is your headlight switch original or a replacement and does it work properly?




Did you remove the prop valve or is it still in the car?