A/C amplifier wiring harness question

[Moby]

I pulled my evaporator yesterday in my FJ-62 to replace a cracked tube. No brainer job, right? Well I'm reinstalling the unit and I've got one wire that I can't figure out where it connects. The wire in question is the single heavy gauge black with white stripe wire that runs into the a/c amplifier (if you're looking at the amplifier it is the single connector on the left). It goes from the amplifier into the evaporator split loom wiring wrap a short distant and then comes out with a single male spade connector.

In the FSM it looks like this wire might route to the ignition. It is supposed to be battery voltage with the ignition on. But for the life of me I can't remember disconnecting this wire when I pulled the evaporator. Can anyone tell me if this wire is used and if so what it connects to?

 

[kevinmrowland]

Haha, you and Rob Faucet need to compare photos.
It is a wire meant to give a signal to the amp when the started is engaged, turns off the amp when starting the car so the starter only has to turn the engine and not the engine and the AC pump.
In your case it is supposed to be connected, in Robs it is not.

 

[Moby]

Yeah, but what is it supposed to be connected to in order to complete that circuit? In the main wiring loom there is a heavy gauge (probably 14) black w/red strip wire that only gets battery positive when the starter is engaged (I verified this). That is the circuit shown in the FSM as pin #5 in the connector and I believe it is part of the circuit that you are referring to.

However this wire has no corresponding connector/wire in my amplifier harness. The FSM shows pin #5 running to the separate connector on the amplifier. But there is no wire in my amplifier harness for pin #5 (so the black/red stripe wire just deadheads in the connector). All of the factory tape is still in place in the amplifier harness. The connector that I've got circled above will not plug into this circuit - first it's a separate connector and second the terminal is too big.

So it looks like this circuit is not complete, at least with the wiring harness I have. I can easily jump from pin 5 in the connector to the larger terminal in my pictures but from what I can tell this circuit was never complete in my truck. Have you actually seen this circuit working?

 

[Rob Faucett]

So if I connect them my 2F turns into a 1HZ with turbo and I don't need to understand what "amp" means!!??

 

[Moby]

Don't get me started on how confusing it is that they call this thing an "amplifier". All it does is tell the dang clutch when to engage

Seriously though, I spent all day looking for something to connect this terminal to. If someone with a FJ-62 wouldn't mind pulling their glovebox out and taking a look I'd be much appreciative!

 

[kevinmrowland]

(so the black/red stripe wire just deadheads in the connector).

Hummmmm, so that there would be the wire that is supposed to go to the separate spade terminal.............
My labeled wiring diagrams are on my other computer, I will take a look at them when I get over to the shop and let you know if it jogs my memory.

And you figured out the secret Rob, your truck is already set up for diesel fuel and turbo, you just need to connect the wires.

 

[Moby]

Hummmmm, so that there would be the wire that is supposed to go to the separate spade terminal.............
My labeled wiring diagrams are on my other computer, I will take a look at them when I get over to the shop and let you know if it jogs my memory.

Thanks! I can always jump it but I'm a little nervous about that without better data.

 

[kevinmrowland]

Well Moby, I haven't seen one that is not connected, that BR wire is supposed to connect to the BW wire and connect to the spade. That is the extent of my knowledge. I have so many bastardized systems in my memory that I do not even remember exactly how it is supposed to be stock, that and I am not a 62 guy.
How bout this, did your AC work right before?
Hook it back up the way it was, and be sure it functions like usual.
Then I would be curious to see if the startup disengage function works or not. You have an 89 so I dont know of any changes that would facilitate this function without the BW wire connected.
Having that wire hooked up or not will not damage the AC, just makes the starter work harder.

 

[Moby]

Thanks, I appreciate you looking into it. Yeah, it worked fine before but I hardly use the A/C. I'm just going to charge it and see what happens. I almost never start with the A/C on anyway. Worst case I'll jump the BR (which my FSM has as labeled as BW) to the BW. Thanks again!