A/C hot/cold - thermistor - read before replacing

[alia176]

It sounds like the OP placed the resistor or the POT in parallel to the thermistor wires. I could be mistaken, however, so I'd like this clarification as well.

 

[hearno]

Wow, ok. I had already had my evaporator and condenser replaced, so it sounds like you did have a different problem. I'm surprised modifying the evaporator temperature reading made a difference at all with a blocked condenser, that's why I thought you were on the right track. I probably should have mentioned that you want to rule out restrictions in the system before going this route, but I guess at the end of the day you now have a way of making your A/C ice cold in the summer when you aren't worried about it icing up. Could be that I just have a drifting evap temperature sensor, but it never got very cold even with the previous evaporator and I would hope the new unit came with a new sensor (the one thing I did not do myself, was just too busy at the time).

I mentioned it in my original post but I probably should have called it out more directly - if you jumper that evap temp sensor with a 2kΩ resistor and the A/C goes from being coolish 55F to blasting ice cold air then your A/C is mechanically sound and the evap sensor is a potential culprit.

Glad you got it worked out!

Hey, saw you were here a month ago. Tried to send you a pm but it wouldn't go through. You able to check back in on this post?

 

[Cezar]

Glad I caught this thread. I replaced my entire system and it works but on super hot days it fails to keep up and I have lots of cycling (like 3 times a minute). Pretty sure this is what my issue is.

 

[Cezar]

I want to embark on this but I have some un-answered questions:

- Why are there 3 connections on the variable resistor? Shouldn't there only be two?
- Why is there no range listed for the variable resistor? It just says 20k ohm but shouldn't it be xxx - 20k ohm?
- And then, what knob settings map to what resistance settings? Or do you have to measure the pot with a multimeter to find out what setting it is at?
- Do I need to solder the connections or is there a type of spade connector that fits the pot?
- Which side of the thermistor do I wire the resistor to? (pretty sure it doesn't matter)

Hopeful to get a response but if not I'll work through these problems myself and follow up either later this fall or next spring.

 

[Cezar]

Got these items figured out:

- Why are there 3 connections on the variable resistor? Shouldn't there only be two?
There are multiple ways to wire a variable resistor depending on the performance desired, but you use wiper terminal + r1 to go from 0 to 20k and wiper terminal + r2 to go in reverse (20k to 0)

- Why is there no range listed for the variable resistor? It just says 20k ohm but shouldn't it be xxx - 20k ohm?
The range is 0 ohm to 20k ohm, or you could use r1 and r2 and get exactly 20k ohm with no effect from the knob

- And then, what knob settings map to what resistance settings? Or do you have to measure the pot with a multimeter to find out what setting it is at?
These are generally linear with some tolerance variation. Just check with a meter if you want to know exactly

- Do I need to solder the connections or is there a type of spade connector that fits the pot?
Still usure on this but I ordered the variable resistor so I'll figure it out when it arrives

- Which side of the thermistor do I wire the resistor to? (pretty sure it doesn't matter)
This apparently needs to be on the SIGNAL side which according to this diagram would be the GREEN wire. 80% sure on this, would love confirmation.

 

[Cezar]

Pulled the glovebox and checked the wiring for the thermistor. The colors do match the diagram. There isn't a lot of room to work with the wiring and I don't want risk screwing it up trying to crimp it so I think I want to get a set of pigtails for both ends.

Anyone know where to find these:

EDIT: The part number to search is 90980-11918. Amazon actually has male / female pigtails. Unfortunately the lead times are over a month out, so it might be easier to call around to junkyards.

 

[alia176]

Pulled the glovebox and checked the wiring for the thermistor. The colors do match the diagram. There isn't a lot of room to work with the wiring and I don't want risk screwing it up trying to crimp it so I think I want to get a set of pigtails for both ends.

Anyone know where to find these:

EDIT: The part number to search is 90980-11918. Amazon actually has male / female pigtails. Unfortunately the lead times are over a month out, so it might be easier to call around to junkyards.

Wow, thank you very much for the legwork you just did for us. I'll be doing the same thing as you as i think it's a great idea to have a pigtail with a factory connector. This allows you to return to OEM config any time you want easily. Freaking genius!!!!

Your part # on amazon produced this listing, but the pic doesn't quite match. https://a.co/d/0dBK3g26

 

[Cezar]

Wow, thank you very much for the legwork you just did for us. I'll be doing the same thing as you as i think it's a great idea to have a pigtail with a factory connector. This allows you to return to OEM config any time you want easily. Freaking genius!!!!

Your part # on amazon produced this listing, but the pic doesn't quite match. https://a.co/d/0dBK3g26

Here are links to the correct parts (I think):

Amazon.com: automotive connectors 2 Pin 7282-5845 7283-5845 7282-5846 90980-11918 Automotive Ambient Light Cable Socket easy replacement(Female with wire,1PCS) : Automotive

Buy automotive connectors 2 Pin 7282-5845 7283-5845 7282-5846 90980-11918 Automotive Ambient Light Cable Socket easy replacement(Female with wire,1PCS): Harness Connector Repair Kits - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Amazon.com: automotive connectors 2 Pin 7282-5845 7283-5845 7282-5846 90980-11918 Automotive Ambient Light Cable Socket easy replacement(Male with wire,1PCS) : Automotive

Buy automotive connectors 2 Pin 7282-5845 7283-5845 7282-5846 90980-11918 Automotive Ambient Light Cable Socket easy replacement(Male with wire,1PCS): Harness Connector Repair Kits - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com