Wire harness modification from ac to just heat

[1973 Chevy]

I have decided to switch over from air conditioning to only heat on my truck. My cab I am going to use has the firewall setup for just heat and I also have a heater core and the vent stuff on the inside. Also I'm not sure but I think I have the wiring harness for the heater. But my cab im stealing the entire harness from is setup for ac and heat. So how much modifications am I going to have to do to switch over. I realize im going to have to get a new control panel on the dash but I was going to anyways. Also if I got a new dash bezel for heat only will that fit in right into my ac dash?

 

[89Suburban]

The bezel should fit fine. But I believe not only the wire harness issues have to be addressed, but also the vacuum harness or lack there of.


Sent from muh IDGAS.

 

[1973 Chevy]

The bezel should fit fine. But I believe not only the wire harness issues have to be addressed, but also the vacuum harness or lack there of.


Sent from muh IDGAS.

So would I be better off to find a harness out of a cab with heat only?

 

[J Knight]

If I'm not mistaken, the only thing on the a/c that is powered is the fan and the a/c compressor. The rest of the system is mechanical. You might only have to tuck away the lead for the compressor. The only other issue I can think of is if the control panel has a different number of fan speeds. I think non a/c has 3 speeds and a/c has 3 and 4 speed fans.

 

[89Suburban]

I never personally swapped them, just guessing. I don't think non-ac trucks run any vacuum actuators, I think they are all cable controlled.

 

[FRANKENTRUCK]

I've been wondering the same thing because my truck came with an after market in dash air conditioning unit . I have pretty much decided to put in a new heating unit and leave it at that . I need to know how to take out the old aftermarket air conditioning unit .

 

[1973 Chevy]

If I'm not mistaken, the only thing on the a/c that is powered is the fan and the a/c compressor. The rest of the system is mechanical. You might only have to tuck away the lead for the compressor. The only other issue I can think of is if the control panel has a different number of fan speeds. I think non a/c has 3 speeds and a/c has 3 and 4 speed fans.

I didnt even have the compressor on the engine when I got the truck, and I have the control panel and the whole vent system, heater core, and fan from a cab I had bought.

 

[J Knight]

I didnt even have the compressor on the engine when I got the truck, and I have the control panel and the whole vent system, heater core, and fan from a cab I had bought.

If that's the case, you should only have to plug the fan in. Like I said in my previous post the fan switch should be your only issue. If they both have the same speeds it should work.

 

[1973 Chevy]

If that's the case, you should only have to plug the fan in. Like I said in my previous post the fan switch should be your only issue. If they both have the same speeds it should work.

Thats good then, I will just have to find out when it gets to that time.

 

[bulldog69]

I have decided to switch over from air conditioning to only heat on my truck. My cab I am going to use has the firewall setup for just heat and I also have a heater core and the vent stuff on the inside. Also I'm not sure but I think I have the wiring harness for the heater. But my cab im stealing the entire harness from is setup for ac and heat. So how much modifications am I going to have to do to switch over. I realize im going to have to get a new control panel on the dash but I was going to anyways. Also if I got a new dash bezel for heat only will that fit in right into my ac dash?

Yes the switch control with ac and the one without ac r the same size . as far as mods go on the wiring harness u will be fine u just wont have a ac pump to plug into the harness. you can just cut the pigtail off that went to the ac and fold the ends of the wire over and put some heat tape on it.