FJ to Can Spec diesel conversion w/24v compressor clutch

[rchalmers3]

To all,
I received the following private message:

Hi there,

I am gathering parts for my AC install on my 2H thanks for all the good info, I got a 24V OE compressor for 50$ and a 2nd good 24V clutch assembly for 25$... both from fellow mudders... Private Parts is waiting for a picture from me of the compressor to determine if they have the engine bracket and some other parts. Should be great!

I read some thread where you mentioned 12V coming off a little black box in the 24V HJ wiring harness on the passenger side fender well. I have that box, could you elaborate on the wiring/purpose/what you did? I have a 24V to 12V converter... I need to run my CB and radio and my cig light 12V.... my convertor only has 2 outlets for 12V and I am not sure how to even wire it. I can't find instructions for it online, it came with my donor rig.

Any help is appreciated

jeff

Jeff,

Great to hear from you! Sounds like A/C is in your future!! Hope all is well with you and your family. I am replying to your private message here since I am not able to include pics attached using private message.

I made a diagram and include a photo to identify the stock amplifier, where all the new relay connections will be made, thus replacing the amplifier. You will have to do a little research with a test light and volt meter. I do not recall the wire coloring or pin locations, and I am too lazy to go poking around in there 'cause it's all neat and tidy at the moment. Plus it works!

I recommend you take a few moments and investigate this part of the install now while you are waiting for the hard parts. There is no penalty for having the control circuit prepared in advance of receiving the compressor and brackets!

Your 12v converter (I assume our trucks are similar since I followed your swap procedure with another Canadian spec truck) actually provides 12v in a variety of places I never imagined. I found the little push button A/C switch on my truck was supplying 12v! So don't worry about stringing more wires to your converter. I found everything I needed all on one plug at the A/C amplifier.

First, disconnect the plug at the stock amplifier in the photo below. The photo is taken from the passenger door looking in through the glove box hole. As I recall there are 8 wires on the connector on my truck. You will need 4 or 6 of them, depending on how you choose to provide A/C system protection.

Using a test light, volt meter, and accurate wiring diagram, identify the following:
1) 12v switched power
2) Ground
3) 24v source (line)
4) wire to comp clutch (load)
5) Thermister in
6) thermister out

To make your system function at a basic, unprotected level, connect items #1-#4 above to your new relay using the diagram provided. Again, you are bypassing the amplifier for a relay operation.

I purchased a 12v, 20a relay for my install. My thinking is that the 24v line/load is at a lower current than it's 12v rating. Plus, a 24v relay may not close with a 12v signal.

There are three possibilities for protecting the A/C system from damage or freezing. Each choice will interrupt the relay operation in some manner. The protection devices and suggested points of addition to the relay operation are listed on the table in the diagram. You need to know if any protection switch you will be adding is normally open or normally closed to assure proper activation of the compressor as well as proper protection.

I hope this info solves the control circuit portion of your A/C install. Feel free to post any problems/questions arising from your own situation.

Rick

 

[Wayneraintree]

Hey Rick,

that rocks! I am going to try to do the prep work on the wiring before I get the parts. your info is very helpful, thanks for taking the time.

I will post up Q's as I need, I appreciate your help.

A/C will be so nice again : )