AC Thermostat Part # & Testing

[BluEagle86]

Working on an 86 Model 30 wagon with the 258 I6 and factory air.  Have a good charge of freon and the pressure valve is functioning yet the compressor cycles on & off and the temp only gets down to 60 degrees.  I suspect the AC Temp Thermostat behind the glovebox.  (Electric switch with capilary tube into the evap)

I plan to bypass it to temporarily test if it is at fault - it makes the "click" when it turns on/off the compressor and seems stuck at 60 degrees since it works continuously until the air gets to that temp.   I can't seem to find it in the parts book listing for factory air to get the part #.  The add-on air is listed P/N T1054062 - is it the same on the factory system?  Is there a modern replacement?  Any tips/tricks with testing or repairing it would be appreciated.

Another member posted this photo of the AC Thermostat, not sure if it will work here:

[macdude443]

I replaced mine.  I found no modern equivalent and got lucky with a NOS unit that looked very familiar on eBay.  I had the seller measure the length of the capillary tube and it just reached.  I tested mine by touching the end of the tube to an ice cube.  It would quickly click off.  When removed from the ice it would click/engage a few seconds later.  The problem with mine (and probably yours), is the shaft the lever connects to had stripped out/seized internally.  It's a bad design.  The replacement switch I bought is much better.

Info on part I used to replace the original:

PART # 369-3080   GRP# 13.477




The bad one I removed:  (1986 Eagle, Factory AC)

[eaglefreek]

I'll  be watching your progress. Mine's doing exactly the same thing. Stays at 60 degrees and compressor cycles on and off.

[macdude443]

Jump the wires across the thermostat and see if it still cycles on/off. If it does, its not the thermostat.

[Dubv]

Piggybacking on this post...I ordered an A/C Thermostat that was advertised as being for an '84-'87 Eagle on ebay.  It came in an NOS AMC/Renault box...but it looks nothing like the pictures you all have posted and I'm wondering if I got the wrong thing.  I have an '84 Eagle...the part that arrived is a small plastic black module with a pin connector on it..not the spade connections like in the picture and there's no lever or lead coming off of it...
I haven't looked for the old one in the car yet..you all mentioned its behind the glovebox, how is it accessed?

[AMC of Houston]

Regarding the part itself, you may have got the "American Air" version of the thermostat (for the dealer add-on A/C systems).   The correct AMC part number for "factory air" version I think one you want is J3728088.    What part number is the one you got??   The "American Air" version is T1054062.

[amcfool1]

hi, 60 degrees seems pretty cool to me. How cold is the AC supposed to get? I will be fixing mine shortly. thanks, gz

[Dubv]

The part number is listed as 8956001959. Its in an AMC box and has an AMC parts order sheet stapled to it, but I'm thinking maybe its for an Alliance, or a Jeep...and not the Eagle and the ebay seller just mis-advertised it?

[AMC of Houston]

I checked my Jeep/Alliance/Encore parts books, and couldn't find it.   If I'm remembering my dealer days right, the numbers starting with "89" were for the Frenchie-based Renault models sold over here, like LeCar, Fuego, 18i, etc.    Afraid I don't have parts books for those.

[Dubv]

Gotcha-Thanks for checking.  I'm hoping he'll take a return.  I've ordered one of the correct ones now.  How do you get access to where its mounted?

[AMC of Houston]

According to the manual, you have to gut the center section of the dash (remove the package tray, center dash pod, radio, and center air duct) for access.

[eaglebeek]

hi, 60 degrees seems pretty cool to me. How cold is the AC supposed to get? I will be fixing mine shortly. thanks, gz

Air temperature from the A/C duct in the center of the dash should be around 45 degrees in a properly operating A/C. The coil temperature, which is what the thermostat senses, ideally should be just above freezing.

From an engineering viewpoint, the thermostat is there to keep condensation from freezing on the coil and restricting airflow across the coil. The adjustment is to allow the driver to adjust the temperature to comfort. Many Eagle owners who were in desert climates jumped the switch.

 

Piggybacking on this post...I ordered an A/C Thermostat that was advertised as being for an '84-'87 Eagle on ebay.  It came in an NOS AMC/Renault box...but it looks nothing like the pictures you all have posted and I'm wondering if I got the wrong thing.  I have an '84 Eagle...the part that arrived is a small plastic black module with a pin connector on it..not the spade connections like in the picture and there's no lever or lead coming off of it...
I haven't looked for the old one in the car yet..you all mentioned its behind the glovebox, how is it accessed?

.
If you're going to jumper the switch the only parts you need to remove are the glove box door and the glove box lining inside the door. You can then get to the connection on the switch body and insert your jumper.

I jumpered mine and left it that way. The only down side to this solution is that the driver must occasionally shut off A/C to allow ice on the coil to melt. How often you need to shut it off is dependent on relative humidity and temperature. You will know the coil has frozen up by decreased air flow from the A/C duct in the center of the dash. It is important when it freezes up that you shut it off to avoid damaging the A/C system.

[macdude443]

I pulled the glove box door and inner lining as well as the radio pod and radio so I could get some light in there.  I removed the thermostat using the radio hole and used the glove box access to help fish the capillary tube into the evaporator.  NOTE:  There is a small fastener holding the capillary tube to the duct where it enters the evaporator housing.  Mine was covered with foam.

Don't kink or bend that tube too much.  If it cracks I'd imagine you're SOL.

With my system recently charged with R12 the shop found my A/C temp to be 39* at the center vents.  This was on an 85 degree day.

[eaglebeek]

Don't kink or bend that tube too much.  If it cracks I'd imagine you're SOL.

With my system recently charged with R12 the shop found my A/C temp to be 39* at the center vents.  This was on an 85 degree day.

You're doing well to get 39* out of your A/C.

You're also doing well to find R-12. That stuff has been listed by the EPA as an ozone-depleting substance. It's manufacture was banned in the mid-1990s by presidential executive order. What's available now is reclaimed/NOS and is very expensive.

[macdude443]

Don't kink or bend that tube too much.  If it cracks I'd imagine you're SOL.

With my system recently charged with R12 the shop found my A/C temp to be 39* at the center vents.  This was on an 85 degree day.

You're doing well to get 39* out of your A/C.

You're also doing well to find R-12. That stuff has been listed by the EPA as an ozone-depleting substance. It's manufacture was banned in the mid-1990s by presidential executive order. What's available now is reclaimed/NOS and is very expensive.

I didn't want to muck around with an R134a conversion if I didn't have to.  I got VERY lucky and found a service station ten minutes away that still had their R12 container.  They had an issue with their gauges so they charged it using the sight glass.  They said they were happy to get rid of it as no one ever requested it anymore and only charged me $40 in labor!  Talk about lucky!