Full Size Jeep Network

Hello, I have been away from this forum for a long time dealing with some serious health issues. Now that I am getting some mobility back, I thought that I would work on the A/C system in my 79 Chief.
The underdash ON/OFF switch on the Left is 'crunchy' to operate and does not properly activate the individual settings. I'd like to replace just that one ON/OFF switch, not the right temp switch.

Does anyone know a part number for the replacement or aftermarket switch that can be used to replace the Left switch, and fit in its place with a new knob?

Thanks very much for your help with this.

Fast

According to the TSM (you can see it here, page 34: https://www.fsjnetwork.com/tech_docs/75 ... manual.pdf), the left switch is the thermostat, and the right switch is the fan control. This is how I recall the A/C in my J10 also.

This should be the thermostat switch: https://teamgrandwagoneer.com/ac-evapor ... 1978-1985/

It does require pulling the underdash unit out to hook up, as the probe at the end of the copper line has to go up at the initial air inlet.

Do you have a picture of which switch exactly you are talking about? I have started rebuilding some of the dash switches for the 70's FSJ's. I was already do that for the 80's, but I recently started experimenting with some of the 70's switches that people thought were no longer any good and were going to throw away and I have had a pretty good success rate with them. Some of them are beyond repair and catastrophically damaged, but I would say a high percentage of them that customers have sent to me have been repairable.

The switch I'm referring to is in the small cluster of 2 knobs in the underdash control panel. In 1979 there are only 2 knobs right next to each other in this control panel. The bad switch is the LEFT one in my truck. My understanding is that the RIGHT switch has the copper line running back to the thermostatic expansion valve in a 1979 Cherokee Chief.

So Stuka I believe you have it backwards as to which switch does what. The LEFT knob is the ON/OFF for the unit and it also controls the Fan speed for my Jeep. The RIGHT knob controls Temperature only, and is therefore the temperature expansion valve adjustment.

I have now looked at the 'manual' that you posted stuka ... it covers many different AMC models for those years and this brings great confusion to this subject as Gremlins and Matadors and Wagoneers used different interior A/C units in those years.

I can post a picture of the control knobs if someone can remind me how to downloads pics into a post? It's been so long since I last did it, I've forgotten.

Thanks guys.

Fast79Chief wrote: ↑Thu Jul 01, 2021 8:54 am The switch I'm referring to is in the small cluster of 2 knobs in the underdash control panel. In 1979 there are only 2 knobs right next to each other in this control panel. The bad switch is the LEFT one. My understanding is that the RIGHT switch has the copper line running back to the temp modulator (not the technical name for it).
So Stuka I believe you have it backwards as to which switch does what. The LEFT knob is the ON/OFF for the unit and it also controls the Fan speed. The RIGHT knob controls Temperature only.

I can post a picture of the control knobs if someone can remind me how to downloads pics into a post? It's been so long since I last did it, I've forgotten.

Thanks guys.

Ah ok, yea I haven't gotten my hands on any of those switches yet. That is the one that is in between the vents and has "FAN" on the left side and "TEMP." on the right side, correct? If you do end up replacing the switch and you plan on throwing it away, can you message me please? I may be interested in it to see if it is something that is repairable. Thank you.

Josh

That's correct Josh. They are 2 separate switches behind that little plastic panel. I'm needing the LEFT switch only.
Let me know if you can locate one or a part number please.

Thanks again.

You can probably contact Watson And Son's Jeep Salvage and I am guessing they have one. They are very fair on prices, very honest and they ship out. They are located in NC. If you have Facebook, it is quicker to send them a message. Otherwise their phone number is 252-944-5526. It is a father and son operation and the son has a normal full time job, so sometimes if you call they may not answer right away, because the father may be with a customer. That is why I was saying that sending a message would be quicker. But if you do end up getting a switch and are going to throw yours away, I would be interested in it, so I could take it apart to see if it is possible to rebuild them and if it would be worth the effort.

Fast79Chief wrote: ↑Thu Jul 01, 2021 8:54 am I have now looked at the 'manual' that you posted stuka ... it covers many different AMC models for those years and this brings great confusion to this subject as Gremlins and Matadors and Wagoneers used different interior A/C units in those years.

That's why I mentioned to look at page 34, which was the page for FSJs.

It's a fairly standard switch. I picked one up at NAPA years ago.

Something like this would probably work.

https://www.littelfuse.com/products/swi ... 96_11.aspx

Like the OP says ... would be great to find the PART # for the original switch in the control panel.

Thanks.

runuover86gw,
how about I send you my switch and you rebuild it? How much?

Fast79Chief wrote: ↑Thu Jul 01, 2021 3:18 pm runuover86gw,
how about I send you my switch and you rebuild it? How much?

As long as it is able to be rebuilt and there aren't any parts that are catastrophically damaged that either aren't available or I am incapable of fabricating or any of my local sources can fabricate. If I have the parts in stock to rebuild it, I would do it for you just for the price of shipping. Since I haven't taken one of these apart yet, I am curious to see if it would be able to be rebuilt. Sometimes my curiosity gets the best of me and I have been wanting to look at these switches to see if they can be rebuilt or if there is a failure point in them that can be improved and fabricated. And if it comes down to it and it can't be rebuilt, I plan on going down to Watson and Sons' Jeep Salvage, not this weekend, but next weekend if they are open and I can pick one up for you at that point. I can message him ahead of time to see what they are charging for them and then let you know if that price works for you. Sometimes, these switches just need a good cleaning inside and out on the terminals and the connectors.

I pulled out the switch. How do you post pictures on here? Can anybody walk me through it?

Thanks.

Super common switch available from Ranshu in Reno part # 21-0031
Amazon has the switch part# SW2400C (long Shaft) or Sw1000C (short Shaft) these are from UAC and are made in China the switch from Ranshu is an original "INDAK" which I would prefer>

The factory switch is a Rotary style switch. It has just 3 wires going to the back of it, 2 Reds and 1 Black. This allows infinite adjustment of the fan volume after you click past the first 'Pre-Compressor' indent, then the next indent is HI Fan, then as you rotate the dial clockwise it allows you to adjust all the way down to a very low position on the Fan. With a 'box' style switch you will only have a high and a low fan.
If someone wants to volunteer an email address I'll send you the 4 pictures I have of this switch since I took it out. I ask that you post them here in this Thread please.
Thanks.

oops wouldn't download pictures

sonoraed wrote:Here ya go


Sent from my iPhone using Tapatalk

That would be SW2000 or santech MT1360


Sent from my iPhone using Tapatalk

sonoraed,
Need a 3 prong rotary switch. You know how to upload pics on here?

I have always used TapaTalk but doesn't seem to be working well uploading images lately, but you can Google the above part numbers and see the switch,what you have is a one wire blower motor whose speed is controlled by the resisters on the blower switch, my 79 J10 used a 3 wire (plus ground) blower motor which used the 5 prong blower switch, Autozone uses Santech Part number, not a big deal

No ... that's not what I have. I'd post a picture of what I have if I could.