Heater Fan- Reg heater vs AC Heater

[71 super]

I checked in one of my stashes today and could not find the bracket. I will chech some of my other hiding holes and see if I can find you one. I will let you know.

[tjvending]

Thanks, 71 super

Looks like I need one, also maybe a switch.

TJ

[mrein3]

Check the switch connector and the condition of the wires in it before you replace the switch.

[tjvending]

Is there a special way of checking this? Should I clean the contacts with something? I'm going to test the switch by jumping a short wire from the brown wire to each contact to see if the fan will come on. I getting the med speed.


TJ

[kxnomore]

It looked like from your pictures that you had the old hvac selector/ controller box still in the dash. The bracket you need to mount the new control box may be still attached to your old one? That happened to me a while back and I was so happy I didn't toss the old one!

[tjvending]

I don't see it, I don't have. I need it!

TJ

[tjvending]

I did some more checking on the wires today. I finally got the switch working. One of the wires going into the controller plug was loose. I now got the switch working. I do have another question: When I go throught the speeds on the switch, I get a low speed, then a med speed and then on the last one it goes back to a low speed. Shouldn't this be a hi-speed? Still need a bracket to get the controller installed. TJ

[71 super]

found an extra bracket, need an address

[tjvending]

Thanks to 71 Super, he's sending me the bracket I need. Does anyone know if any of the cables for the reg Heater control will work on the AC Controll? TJ

[tjvending]

I took the truck out to get it warm up to see if the heat will get warm. I getting nothing but cold air. How can I make it to blow warm air? I have it set up that air is coming only to the windshield. The air condition side is not hooked up. I'm using only the blower at this time for heat. TJ

[haysonj]

there is a vac port on the heater hose under the hood that has to have vac to it also cable from controls switches from heat to AC under the hood.

[tjvending]

I went under the hood and switch the lever on top of the AC box to the opposite way and now I have heat! Is this where one of the cables go to? AC/Heater cable?

[kxnomore]

Yes, the cable for the hot and cold lever (bottom lever) goes through the firewall and attaches to that lever on top of the heater core box.

It is the longest cable, I believe, and will need a metal clamp to hold down the sheath of the cable. It looks kind of like a small distributor hold down clamp. Might be the same as from any truck of this era, maybe a junk yard would have one if yours is missing.

[mrein3]

Originally Posted by tjvending

I did some more checking on the wires today. I finally got the switch working. One of the wires going into the controller plug was loose. I now got the switch working. I do have another question: When I go throught the speeds on the switch, I get a low speed, then a med speed and then on the last one it goes back to a low speed. Shouldn't this be a hi-speed? Still need a bracket to get the controller installed. TJ

Are you still experiencing low fan speed on the high switch setting?
If so you're probably having issues with the relay. Note that the realy may be good and the high current supply to the relay may be bad. Trace the orange wire back to the battery. On lots of GM vehicles of this vintage there is an in-line 20 amp fuse on an orange wire that supplies current for the high speed setting. For the relay to work you need 12 volts on that wire, and a voltage from the switch to switch current from that big orange wire to the fan.

I owned my convertible since the late 80s. This past summer I was snooping around under the hood and found that a previous owner eliminated the fuse for the high speed fan current and simply twisted that wire together where the fuse holder was. Can you say fire hazzard? I soldered in a new fuse holder. On my truck, I converted my non-AC truck to Ac. I used a different relay than stock but it works like the stock set-up. When my fan switch is on high, it switches the relay on. That relay gets its current from a 10 or 12 gauge wire, through a 20 amp in-line fuse, right from the battery.

I hope this helps.

[tjvending]

MREIN3, I don't see this wire around the battery, I do see the juction box but wires are black. Do you have a picture a wire digram on this? TJ

[71 super]

sent the bracket out yesterday around 3:30 should see it by friday. H

[mrein3]

Looking at the wiring diagram pictured earlier, it looks like the high current supply to the relay is under the dash. I colored the wire that I think is the correct one. Make sure you have 12 volts on that wire at the relay and 12 volts from the switch when set on high.

If the relay is working, and you have 12 volts from both those wires, you should have 12 volts on the purple that is headed out to the fan.

[tjvending]

Mrein3,

I check out the relay orange wire today, I getting 12 V from all three area's you had me to check. Still a low speed on the high setting. Also can you tell me the routing of the cables for the controller? TJ