a/c compressor "kill" switch

My understanding is that the Diablo A/C compressor is "always on". I assume that if you set the temp on the console inside the cockpit high enough, the compressor will stay off, but then you would have to deal with the heater coming on if the setting was above the ambient temperature. Anyway, those of you that have installed an A/C compressor "kill switch", did you do it right at the compressor in the engine compartment, and leave the switch there?.......did you just unplug the compressor lead wire during cooler weather?, or did you run a splice into the lead wire and run the wire back into the cockpit with a switch mounted possibly under the dash? Did you use a relay, or just hard wire a switch?

 

Thanks for your input.

Topcarbon and I mounted a small switch in the center console. The switch activated a relay that was installed on a small frame rail near the compressor.

 

If you wanted to keep it super simple, just reach down and unplug the single wire for the a/c clutch during the cold season.

 

The secondary reason for the switch was for those times the engine was getting too hot (115 deg in Phx). Some Diablos seem to heat up easier than others. By stopping the flow of freon, the condenser did not heat up and that had a small impact on the left radiator to help keep the engine that much cooler. In an unexpected traffic jam, it would be enough to keep the engine temp in the safe range.

Gary, you did a superb job on the yellow Diablo. Car rran 5 degrees cooler and a little stronger after the install.

Topcarbon and I mounted a small switch in the center console. The switch activated a relay that was installed on a small frame rail near the compressor.

 

If you wanted to keep it super simple, just reach down and unplug the single wire for the a/c clutch during the cold season.

 

The secondary reason for the switch was for those times the engine was getting too hot (115 deg in Phx). Some Diablos seem to heat up easier than others. By stopping the flow of freon, the condenser did not heat up and that had a small impact on the left radiator to help keep the engine that much cooler. In an unexpected traffic jam, it would be enough to keep the engine temp in the safe range.

 

Gary,

 

Do you still have your black Diablo?

Also, what type of relay did you use?

Did you use one with the diode voltage spike suppression across the coil,

or just a straight relay? (four prong?)

 

 

Gary,

 

Do you still have your black Diablo?

Also, what type of relay did you use?

Did you use one with the diode voltage spike suppression across the coil,

or just a straight relay? (four prong?)

Gary sold his car to 3dogsplumbing

No, I had to sell her almost 2 years ago. I had a chance to buy some land, but it fell through. It wasn't long after that the economy started getting strange so I never picked up another one.

 

I just used a standard 5 pin 30 amp water resistant relay. I didn't opt for the diode because I used the original a/c clutch power wire to flip the relay AND power the clutch. The switch I installed in the center console simply allowed the winding part of the relay to go to ground when turned on. That deactivated the contact.

 

Again, my purpose was to only deactivate the a/c clutch when the car was stuck in traffic or if I was running it hard. During the winter months I left the clutch unplugged from its original connection.

No, I had to sell her almost 2 years ago. I had a chance to buy some land, but it fell through. It wasn't long after that the economy started getting strange so I never picked up another one.

 

I just used a standard 5 pin 30 amp water resistant relay. I didn't opt for the diode because I used the original a/c clutch power wire to flip the relay AND power the clutch. The switch I installed in the center console simply allowed the winding part of the relay to go to ground when turned on. That deactivated the contact.

 

Again, my purpose was to only deactivate the a/c clutch when the car was stuck in traffic or if I was running it hard. During the winter months I left the clutch unplugged from its original connection.

 

Sorry you sold the "D".

 

Anyway, just so I understand, you switched the "ground" end of the coil (winding), so when the console switch was "on" (closed), this allowed the A/C clutch to be activated by the relay. The single red wire that went to the A/C clutch feeds the "positive" side of the coil AND one end of the load switch in the relay. The other end of the load switch goes to the A/C clutch. When the switch is turned "off" (open), this keeps the relay coil from being grounded, and therefore cannot

close the relay load switch to the A/C clutch. Is this correct?

I did this on my 92 too!

Does the 95 compressor run all the time also?

Does the 95 compressor run all the time also?

I always thought it was limited to the early Diablos

I always thought it was limited to the early Diablos

 

On my '99, the A/C clutch kicks on whenever the console setting is colder than ambiant temperature.

If you set it a little high, the heater comes on. There is no "A/C on/off switch".

I always thought it was limited to the early Diablos

No they all come on.

No they all come on.

fucked up design.

Buy a Countach! Then you will not have to worry about silly things like air conditioning.

 

Even when it's running you can't tell it's on

 

You can turn the compressor off if you have a pre 1988 1/2 car though.

It's definitely an annoyance, but then so are most "automatic systems" That think for you. I hate it when the car try's to figure out what you want.

It's definitely an annoyance, but then so are most "automatic systems" That think for you. I hate it when the car try's to figure out what you want.

 

i agree

 

it is good to know there are MUCH more annoyng cars in that way than a diablo though

Anyway, just so I understand, you switched the "ground" end of the coil (winding), so when the console switch was "on" (closed), this allowed the A/C clutch to be activated by the relay. The single red wire that went to the A/C clutch feeds the "positive" side of the coil AND one end of the load switch in the relay. The other end of the load switch goes to the A/C clutch. When the switch is turned "off" (open), this keeps the relay coil from being grounded, and therefore cannot

close the relay load switch to the A/C clutch. Is this correct?

 

Not exactly.

 

 

 

 

The a/c clutch wire (which is hot) coming from the car is "y'd" before the clutch to connected to 86 and 30. 87a is connected to the clutch. 85 goes to ground when the switch is in the "on" position. 87 is left unused.

 

This way the compressor runs normally at all times except when you flip the switch. Maybe the engine is getting too warm. Maybe you want an extra 5hp boost for a moment.

 

I hope that helps.

 

Not exactly.

 

 

 

 

The a/c clutch wire (which is hot) coming from the car is "y'd" before the clutch to connected to 86 and 30. 87a is connected to the clutch. 85 goes to ground when the switch is in the "on" position. 87 is left unused.

 

This way the compressor runs normally at all times except when you flip the switch. Maybe the engine is getting too warm. Maybe you want an extra 5hp boost for a moment.

 

I hope that helps.

 

 

FYI - I have an AC kill switch on my car. Steve (Driven Exotics) installed it before I got it. He said that he installed them on a lot of the Diablos that he worked on. Said it reduces heat in the engine bay in addition to keeping the unit from running all the time. The funny thing is that, when I bought it, the dealership said that the AC was inoperable. When I brought it to Steve, he went in and said "No, I have the kill switch on. Watch this." He then flipped the switch and you could hear it turn on above the motor noise. Classic.

I did this on my 92 too!

 

My dad and I could never fgure out what the switch was for haha