Two speed Acc Drive
 

1985 was the last year for the TSAD for the a/c, so I’m assuming that the computer or the EEC now controls the a/c circuit. My questions are, my car was original a 1992 2.3, which now has an 85 carbureted 5.0. (the computer in my car has been by passed, but everything is still in the car.)
When I connect the compressor, will the EEC or computer control the a/c circuit? Or do I have to install the tsad into my wiring harness. Also the HO has a wot relay in the circuit, the 2.3 doesn’t, how important is this for every day driving? Or is this just a high performance feature?

Re: Two speed Acc Drive
 

I dont know how the TSAD works. What exactly is that?

The WOT is just a protection/performance feature so the engine does not have as much load at WOT. You can just click off the a/c before punching it.

Re: Two speed Acc Drive
 

this is what i found on the tsad. with the throttle wide open, the wot a/c cutout relay opens. It signals the tsad to remove power to the wot cutout relay, cutting off power to the a/c field coil. Also the tsad operates the accessories at half speed to decrease engine load. When the tsad returns from half to full speed operation, a/c is momentarily cut out. and then turned on a few seconds later. and this make no sense to me.

Re: Two speed Acc Drive
 

How does it operate the accesories at half speed. this is what I dont understand.

Re: Two speed Acc Drive
 

I thought that the two-speed accessory drive didn't actually make it to production? It was in the sales brochures and the service manual but it didn't make it past the prototype stage (at least not on V8 cars). Someone correct me if they've actually run across one.

Re: Two speed Acc Drive
 

The only thing I can think of as far as full and half speed is the way the a/c clutch cycles. At idle the clutch stays energized longer then when the engine speed is increased.
According to my manuals, they all show the tsad in the schematics on the HO

Re: Two speed Acc Drive
 

I can see the need for that on the 2.3 for accelerating and such because the AC robs a lot of power. Not a bad idea on any engine really.

Re: Two speed Acc Drive
 

As far as I can remember the half speeds acc drive never went in production. I remember the big deal they were making about it, and how much power it would save, etc. etc.

But, never was on anything I saw or serviced at dealership.

Re: Two speed Acc Drive
 

Good, someone else remebers this too...

Re: Two speed Acc Drive
 

Ok there is a tsad module, when I stripped my donor, what I took out on the passenger side I thought was the computer, , I was looking for the part number on the computer because some ask if I had one for sale, and could they have the part number, were the harness plugs in its stamped TSAD. So the question now is, do I try to install this for the A/C?

Re: Two speed Acc Drive
 

I would be interested in this too because when I bypass my factory ignition and run MSD set up, my a/c wont turn on. I always thought this was some sort of computer too, but I know it does not control much except for the a/c and maybe factory emission stuff?

Re: Two speed Acc Drive
 

I wonder why you’re a/c doesn’t work, didn’t think the ignition was tied into it. You didn’t unplug something? The compressor, or the pressure switch, maybe moving wires around you broke one to the a/c. maybe you just need a charge, did you try by passing the pressure switch to see if it kicks on?

Re: Two speed Acc Drive
 

Well, When I bypass the ignition module (silver box under the hood) I cant get it to turn on. I can run the msd box inline after the stock box and it works. I am thinking the module in the passeneger area controls the ignition module under the hood and in turn controls the a/c.

But now I am going to be running an msd distributor along with the msd ignition so I have to figure it out when i get the car back together.