98 heater control wiring

[rockusaf]

Working on swapping in a 98 dash into my 91 and I got the entire wiring harness (I've got 2 harnesses actually, long story) from a donor truck so I can make everything work but I can't figure out the wiring for the heater controls. 2 of the connectors are obvious but the 3rd looks like it should plug in the back of the switch but there are no wires or anything there, I've got 2 switches but neither have anything in the slot it looks like the plug goes. The plug and where I think it goes are in the red circles in the pic below. Can someone tell me what I'm missing here, or take a look at your truck and let me know where the 4 wire plug with purple, brown, orange and black goes?

http://i82.photobucket.com/albums/j263/rockusaf/Heaterwiring-1.jpg

Thanks a lot,
Rock

[lynx5653]

I could be wrong but I think it goes to the cd player that would be right under hvac control.

[ecvchamp]

The one you have circled on the HVAC controll is for a rear window defroster. That was used on the Tahoe and Suburban. Not sure what the connector you have circled is for.

[ecvchamp]

Are you going to use the heat and a/c system from the 98? I do not think you can ues the control from the 98 with your 91 system.

[rockusaf]

The one you have circled on the HVAC controll is for a rear window defroster. That was used on the Tahoe and Suburban. Not sure what the connector you have circled is for.

That would make sense on the controls since it doesn't have the rear defrost, now if the connector is actually for the cd player I'll be all set. I have all the new motors, resistor and everything from the 98 I pulled the harness from so I think I'll be good with that but thanks for the heads up.

[rockusaf]

I could be wrong but I think it goes to the cd player that would be right under hvac control.

Can anyone confirm this? If so that'd make my life easier since I can just pull all those wires out.
Thanks lynx

[lynx5653]

what did your dash and harness come out of?

[rockusaf]

Dash is out of a 98 C2500 and got the harness with that too, got another harness from a 97 C1500 because I found some melted wires in the original so I'm replacing wires from the 97 harness. I have all the heater blender motors, harness and everything from about 3 different trucks so I'm pretty sure I can get that to work. Just need to sort out the main harness plugging into the 91 but I'm still working on that.

[lynx5653]

if you could get me a close up pic of that connector i can compare it to defrost and cd in a 99 tahoe.
how did you remove harness from firewall in donor truck? trying to remove dash from 99 tahoe but cant figure out the harness, what type and size bolt holds it to firewall.

[rockusaf]

if you could get me a close up pic of that connector i can compare it to defrost and cd in a 99 tahoe.
how did you remove harness from firewall in donor truck? trying to remove dash from 99 tahoe but cant figure out the harness, what type and size bolt holds it to firewall.

http://i82.photobucket.com/albums/j263/rockusaf/Harnesscloseup.jpg

Here you go, its the flat 4 wire connector on the top. It has a thick purple and a black, brown and orange wire.

Pulling the harness is a PIA because there are really 2 runs, one in the dash and another along the firewall. There's nothing but these metal tabs holding the wires to the firewall, they just bend over the wires to hold it, no bolts or anything but all the wires run down in between everything in the firewall so just look for the connectors and unplug everything and pull it out. Take your time and pay attention if you plan to put it back in or take pictures, that's what I did at the junk yard and the 2nd harness I pulled was a lot easier.

Really appreciate the assist lynx

[lynx5653]

that is for the rear defrost I see how the back harness is removed from firewall,but dont see how main harness comes out of dash or how it disconnects from the firewall itself. did you remove convenience center somehow,this is a big pia i must be missing something.

thanks and you are welcome

[rockusaf]

Thanks for the info, nothing I need to worry about. I'll probably just plug it into the back of the controls just so it's out of the way.

I get what your having an issue with now, it'd tight around the steering column and around the parking break but it's hard to explain how it comes out of the firewall. I'll try to get some pics of the harness out of the truck, it'll make it easier to understand how it comes out but yeah the convenience does come off to get everything off.

[lynx5653]

that might help thanks