All sorts of issues with the controls on my 70 vert. - only works in defrost - only blows at high speed - only blows cold air ( though this might be rectified as I find that once I put the lever to cool I have to manually open the door by hand, for soe reason the wire doesn't push it close. Anyways I want to start by checking mu resisitors but have no idea where they are. This car sat for twenty years so connections are rusty and I have no idea how to get at the connectors behind the control levers , do I have to remove my dash to do this?
To access the back of the heater controls, you can remove the radio. In order to do that, if the car has A/C, you need to drop the plastic plenum that directs heat to the floor. Then the radio comes out from the bottom of the dash If the car has A/C, you should look at the most likely suspect- the blowwer motor relay. If hte relay id bad, it will only blow on high
No radio installed so I guess that is a good thing though I still don't know how to get my hands back there. I have ac, where is this relay located? I thought I read somewhere that it is on the fire wall but I am not sure.
You really need to do yourself a favor and buy a factory service manual. It has all schematics, wiring diagrams and funtional description of how the syatem operates. I wouldnt be able to fix my car without it The relay is located on the firewall and is readily available at your local auto parts store. But please, dont just start throwing parts at it until its fixed. The blower resistor is located on the evaporator housing Remember- "Test....dont guess"
these guys know a whole lot more than me but i had these problems and changed the blower resister to solve....got mine on ebay for 35 ddollars....easy fix if im right,marty
addendum.i bought one on ebay for 35 but fixed mine,,,,,,,,found partially disconnected blower resistor and cleaned contacts ,try first to look and clean may be loose,marty
I have the fischer service manual on cd but I can't find these resistors anywhere. My relay is just clicking now so I will replace it and see what that does.
folow what jason says and also pull out the blower resister. its likely loose or just corroded contacts....let us know when you found the resistor...also there delicate .
Also make sure you have vacuum to the black plastic vacuum tank mounted on the firewall. Might be part of your problem
ok.....in my 70 electra it is on the firewall almost touching the passenger valve cover. there is a large plug maybe 2 inches with 4 wires ,that plug attaches to it. you loosen the 2 bolts and out is comes unless it fell inside unless its loose which would cause only high blow, marty
thanks for the replys , mine is and ac car so yes I have determined that the resistors are inside the evaporater. While I was working on this broke the nipple on the ac vacuum tank that mounts on the firewall and it has broken in such away that I don't think I can fix it. My question is that I don't plan to use the ac any ways so can I just bypass it or do I need this for my heating.
I didn't actually find them but I asume they are behind the wire connector that terminates there as I cab see them nowhere else.
I removed my resistor and checked it with a meter. It is a very stout resistor and it would take a lot to damage it. I would suggest cleaning the contacts and reinstalling the one you have. Here's some pics of the resistor. It is on the a/c box below the heater hoses in the engine compartment. It is usually covered with road grime so it may be hard to see at first.
For the vacuum tank, check in the parts for sale thread for people parting out cars - you should be able to find one easily As for the cable that doesnt seem to move the door - there should be a plastic "tang" on the cable that gets screwed somewhere solid. What this does is prevents the cable housing from moving when the inside rod is moved. The tangs can break (usually someone underdash moving stuff around). If this is the case source a cable from someone parting a car. It needs to be the same cable - the tangs are usually color coded Mark should have everything you need http://v8buick.com/showthread.php?t=238755
