I'm replacing the A/C evaporator in my 1993 Dodge dakota V6. I have it out, but there's some sort of sensor sticking into it. It pulls right out and I put it into the new one. It connects to a electcial plug in the truck. What is this piece called? Any Ideas!

 

I have no idea. Post up a pic. The parts manual in the FAQ would have it listed.

 

that sensor you are referring to is the core temp sensor. It sends a signal to the PCM that the evaporator is about to freeze up so that it can turn off the A/C compressor.

 

I found out its called the A/c Probe or A/c thermistor. Any Ideas where I could get one?

 

ancient thread, found by way of Google. I have the heater box out of my 93 as we speak (damn heater core blew) and I went to clean the buildup of leaves out of the AC evaporator while it was apart and bumped this sensor/probe and yup busted it... I cannot find a listing for this sensor anywhere... Mopar parts Whole sale, Advance Auto, RockAuto, and any listings I see for rplacement evaporators do not include this sensor with the replacement evaporators either;


does anyone here know either A) where can I get one of these (no I don't want to go pull a junkyard truck apart just for that sensor)
OR B) how can I bypass this temp probe?

 

If it senses freeze up, you may not need to replace it. It would depend on if the sensor is normally open (when the evap core is not frozen) or normally closed. How many wires are involved? A thermister is a temp actuated resister--as the temp goes lower (probably) the resistance increases--as it approaches freezing, the pcm shuts down the compressor so things can thaw out. It would seem to me that bridging the wires (twisting them together) would create a no resistance situation and the a/c would just run. Could be wrong, of course.

Thermisters are available for like 2011, etc. Maybe you could just adapt one of those probes.

I think I might consult with an a/c shop or a Dodge Dealer () The dealer might be able to get you something--tho a 92 probe might be too much to expect. It is the new, new Chrysler Corp, you know. Stuff made by pre Diamler Chrysler might be considered prehistoric.

 

I called a buddy that has worked for a Dodge dealer since 1991 (I worked there with him for a couple years) and he didn't know either.
and yeah I know about the prehistoric thing. Last week I called the dealer for a fuel filler neck for Mom's car a 98 Intrepid. and it was "discontinued"
the parts guy is the brother to the 1st dealer employee I mentioned in this post and when I called about the fuel filler neck he said "Chrysler has been cancelling parts left and right".
I found a Chrysler factory parts breakdown online and it called out the evaporator core (key # 13) and teh sensor (key # 13A) but in the listing below it called out the the core gave a part number and a price but no mention was made of #13A the sensor.
If someone could tell me whether (or not) I could just either jumper the leads that connect to this sensor and have the AC work, OR just leave it dangling and connected to nothing and have the AC work, I would be satisfied with that. It is a 93 not a new truck any more after all....

 

this is what I am wanting to find out because I dont want to take the damn thing apart twice.

 

A thermister changes it's resistance as the temperature changes and there's most likely a "voltage follower" circuit there somewhere that causes the clutch to disconnect when the temperature reaches a certain level. If you disconnect it completely, the pump clutch might be continuously engaged or disengaged depending on the thermister characteristics, you'd need to try it and see or you can find someone with a similar truck and check out the resistance when the system is warm and when the a/c has been running for a long time to determine the trend - you can also buy a thermister that has a similar trend. The thermister itself is just a small 2 wire component and in the case of this probe, it's located inside it for ease of installation and component protection.

If it has roughly the same characteristics as the older ones, you should be able to do this. The main thing to determine is whether the resistance increases or decreases with temperature and match that. The next thing is to get an approximate value for the cut-off temperature resistance and come close to that (you can fiddle with this by adding series or parallel resistance to the thermister).

I'd start with this choice - a/c shops should know what to use as replacement components for most vehicles and should therefore be able to sell you one that will both fit and work - you may need to change the connector, but electrically, it will be compatible. The dealership may not know - I've found they tend to go by part numbers and availability and if it's not there, they can't help you.

 

This is tough for me (I'm not an expert on electronics.) Without knowing the resistance value for the thermister at subfreezing, it's tough to tell what to do. And does the resistance rise as the temp falls or as it rises.

You put conditions on all this, "I don't want to take the damned thing apart twice." and "I don't want to go find one in a wrecking yard." I'm not being critical here, but it's probably a case of you broke it, and finding a solution is going to entail some pain & effort. You might be able to find an HVAC guy that can help you figure out the electronics. Probably a trip to a wrecking yard is in order--and a thermister off a Ram, an old Ramcharger, or a Dakota would work.

Probably there's no help from the A/C guy at the dealership (they are mostly parts changers.) Tho, it wouldn't hurt to jump in the car or on the motorcycle and go ask (my second car is a KLR.) Bottom line, tho, is that it's probably gonna require that you get off your duff, calm down, and go do some research or get a second hand part from a wrecking yard.