AC Heater Box Wiring Questions

[NOWAY55]

ok, just replaced the AC box with a NON AC box (my 16yr old did)


Also swapped out a NON AC control for the AC control on the dash.

Moved the 4 prong resistor from the old box

Moved the relay over (I assume that's what the little silver box is)

Now for my problems.....

The fan switch works even if the truck is not turned key on ! It didn't do this before.

There is a hissing sound coming from behind the switch on the dash - have yet to take it back apart to check connections.

Is there any other things I need to do to get this to work properly for just some heat / defrost?

Any ideas on why it works when the key is off?

this is a strange thing......

Also, there was a hot wire coming from the fire wall +12 block going through the passenger fender then connected to a quick disconnect and into a group of wires going across the front of the truck infront of the radiator. I left it off just to see if anything would not work but everything seems to work? Any ideas what this is?

 

[Daryl H]

Re: AC Heater Box Wiring Questions

There is a big difference between an A/C and a non A/C fan system.
The non is a 3 position control and the A/C is a 4 position which has an additional relay for the high speed operation. They have no similarity.

Put the regular control back in and call it quits. Probably also fix your vacuum leak back there.

 

[ViciousV6]

Re: AC Heater Box Wiring Questions

No WAy,

Steps!
1. Disconnect all wiring from A/C Box
2. Unbolt from outside and inside Remove A/C box
3. I removed my a/c heater core and replaced with non-a/c heater core.
4. Bolt new Non-A/C Box in with blower motor
5. Remove the resistor on top of the A/C Box and install inplace of the Non-A/C resisitor
6. Start up you truck and all blower function should be operating other than any A/C function because they are not connected to anything.

There is no need to remove the control from inside the truck because all works the same just minus any A/C function.

ViciousV6

 

[NOWAY55]

Re: AC Heater Box Wiring Questions

ok - put the original resistor back in

put the original control back in the dash.

still have the following problem.

key off - if the fan switch is on high, the fan blows high. If it is any other speed, the fan is off. This is even if I select off on the vertical sliding switches.

key on - the fan works low medium high ok. just if I take the key out on high, it stays running?

Thoughts?

 

[ViciousV6]

Re: AC Heater Box Wiring Questions

ok - put the original resistor back in

put the original control back in the dash.

still have the following problem.

key off - if the fan switch is on high, the fan blows high. If it is any other speed, the fan is off. This is even if I select off on the vertical sliding switches.

key on - the fan works low medium high ok. just if I take the key out on high, it stays running?

Thoughts?

Sounds like someone hotwire the A/C relay maybe press switch was bad at one time and they hot wired it, otherwise you turn the key off everything should be off unless wired through battery somewhere.

Ralph

 

[Daryl H]

Re: AC Heater Box Wiring Questions

Was the heater control switch swapped also?