Novak Conversions Jeep Wrangler TJ radiator

Replacement HVAC wiring harness?

Same problem blower motor not coming on at all. I replaced the fan speed switch, hard wired it because the pigtail was melted, replaced resistor and blower motor relay. Checked fuse number 8 under the dash, not blown. Pulled the blower motor tested it by using alligator clips and the battery, it kicked on. My next step is to check the wiring harness to see if I’m getting power to the blower motor but I figured it would save time just to replace it or them. I’m not sure how many wiring harnesses tie in together but I figured save time testing them and just replace it. I am not sure where to start on replacing it though. AND before I do that I just want to make sure I’m not missing something obvious.
 
I’m having the same problem. Replaced the blower motor blower motor resistor and the ac control panel. Worked then stopped. Did the thing everyone said on here with the spade connectors worked then went back to start it up and head to the store doesn’t work again. I noticed corrosion in the wiring how do I change that out.
 
thecraftieokie said:
I’m having the same problem. Replaced the blower motor blower motor resistor and the ac control panel. Worked then stopped. Did the thing everyone said on here with the spade connectors worked then went back to start it up and head to the store doesn’t work again. I noticed corrosion in the wiring how do I change that out.
Click to expand...
Same issue as me, I think my issue is in the wiring harness. Not sure if this is true or not but I’ve been told you basically have to remove the dash to get the wiring harness. I have thought about adding a switch from the battery to the harness and selecting one speed, probably speed #3 then running it to the blower motor. Just know if done like this don’t forget to switch off the blower motor after shutting down the jeep. Sorry I could be of much help but I’ve basically done the same steps you have with no luck.
 
Jod0001 said:
Same issue as me, I think my issue is in the wiring harness. Not sure if this is true or not but I’ve been told you basically have to remove the dash to get the wiring harness. I have thought about adding a switch from the battery to the harness and selecting one speed, probably speed #3 then running it to the blower motor. Just know if done like this don’t forget to switch off the blower motor after shutting down the jeep. Sorry I could be of much help but I’ve basically done the same steps you have with no luck.
Click to expand...

Not sure exactly which harness you are referring to but there is one behind the glove box. You don't need to remove the dash to get to it. I completely replaced all of the hvac wiring without removing the dash

Remember that the voltage thru the switch and resistor is the ground side of the circuit (12v-). The 12v+ side is direct from the engine fuse box to a relay then direct to the blower motor. The relay energizes and you will have 12v+ at the blower when the key is switched on, regardless if you have the HVAC on or not.

Not sure exactly which harness you are referring to but there is one behind the glove box.
 
I am referring to the harness that plugs into the fan speed switch on the climate control panel. If I had to guess there is a short in it somewhere. Blower motor works, replaced the relay, resistor, fan speed switch and verified the fuse was not blown. The only thing I have not replaced is the entire panel itself. I think the issue is the harness because the pigtail at the fan speed switch melted. I cut it off and wired it independently to each prong of the new switch as done in previous post in this forum. This would be great if replacing the harness was relatively easy to get to.
 
CreepinDeth said:
Nice job insulating the connections
Open bare metal connections will corrode quickly
Click to expand...

I am glad I paid attention to this thread, just replaced the 3 prong pig tail with the independent connectors and now the blower motor turns on. I have been chasing this issue for 6 months, it stop blowing about a year ago. Could not drive it to work in the winter because the windshield could not defrost and I was not about to scrape the ice. Now I just wonder how long it takes to melt those connectors but I have comp and collision so if it burns to the ground I’ll get a few “dollarbucks” for her.

0358E7F1-B68C-45D2-A5E3-BCC98F998960.jpeg
 
Jod0001 said:
I am glad I paid attention to this thread, just replaced the 3 prong pig tail with the independent connectors and now the blower motor turns on. I have been chasing this issue for 6 months, it stop blowing about a year ago. Could not drive it to work in the winter because the windshield could not defrost and I was not about to scrape the ice. Now I just wonder how long it takes to melt those connectors but I have comp and collision so if it burns to the ground I’ll get a few “dollarbucks” for her.
Click to expand...

the fix has been good for two years
 
burdetter16 said:
My A/C went out recently so I pulled the control module out today and found this melted wiring harness. I’ve looked every where and cannot seem to find a replacement one.

View attachment 209161

This one looks similar but it says it doesn’t fit a tj: https://www.amazon.com/dp/B0049TTR6G/ref=cm_sw_r_cp_api_glc_fabc_Cwx0Fb3FENXZ6

Does anyone know where I can get this part? It’s from the far right side of the module behind the selector switch

View attachment 209160
Click to expand...

I’m having the same issue except the tj I bought doesn’t have that wiring at all. It’s like someone ripped the wiring harness out completely. I have the 3 spades solution and wiring set up on the A/C control unit but I can’t find where they are supposed to connect to from there. Can anyone send a description or picture of where it needs to insert into?
 
Deadbeep said:
I’m having the same issue except the tj I bought doesn’t have that wiring at all. It’s like someone ripped the wiring harness out completely. I have the 3 spades solution and wiring set up on the A/C control unit but I can’t find where they are supposed to connect to from there. Can anyone send a description or picture of where it needs to insert into?
Click to expand...

How about posting a pic of your wiring and telling us what year your TJ is? They are not all identical.
 
B1Toad said:
How about posting a pic of your wiring and telling us what year your TJ is? They are not all identical.
Click to expand...

99 TJ it has the 2.5L

Here’s a picture of what I’m working with the side with 3 terminals was missing (red) do you have a color code wire diagram for these connections or what are the connection points?

Also the blue side was melted but was able to match from the old plug.

IMG_4940.jpeg
 
OK starting at the bottom terminal (the one that melts and is on the bottom when the control board is mounted in the dash) is the black #12 wire, it goes to ground point 202 which is in the driver's side footwell screwed into the metal. This is where the HVAC switches all get their ground (which is what controls blower speeds and AC compressor operation). The next one is a dark green #12 and it connects to the blower switch plug connector (C1) terminal E. This is what sends the ground signal to your blower speed switch, all the rest go to the blower resistor. The last wire on the top (which will only be there if you have AC) is a light green 20 gauge wire that goes to connector C170 which is gray and black located in the driver kick panel area.

BTW there are factory service manuals complete with wiring diagrams down in the resources section for every year of TJ.
In the diagram connector C3 is the 3 blade connector on the mode switch you circled in red and C1 is the blower speed switch connector.

99 blower.jpg
C170.jpg
 
Last edited:
TrueTexas said:
Skip the connector and crimp on some female spade terminals.pic isn't perfect but I have replaced the vast majority of my hvac wiring. If I remember correctly, those particular terminals require a .187" female spade. $4 for a box of 7 from the auto parts store

View attachment 209170
Click to expand...

very late to this. But have the exact same issue on both the power connector and the fan speed one like the pic. How do I make sure I get those three wire back where they go lol? The ends of my are toast and I all ready pulled it off and now not sure which is whish
 
Ptricktj99 said:
very late to this. But have the exact same issue on both the power connector and the fan speed one like the pic. How do I make sure I get those three wire back where they go lol? The ends of my are toast and I all ready pulled it off and now not sure which is whish
Click to expand...
It's right here in the thread, the post just before yours

lead a horse to water.jpg
 
  • Haha
Reactions: Reign Mack
Novak Conversions Jeep Wrangler TJ radiator
Top Bottom