A/c system Sanden

[71Nissan240Z]

I was just going to rip the ac system out of my 71 Z. But seeing how everything is this and intact, it just doesnt turn on.

Ive traced the problem somwhere between the switch the the relay. The switch has no voltage with it on, so im assuming its the relay. Not sure tho.

Anyways, I found the power wire from the dash going to a tri connection close to the compressor. 1 wire going to the Fan (power), the other wire going to the compressor (power) and the wire coming from the dash.

I decided to just test the ac system by jumping the connection directly to the battery, the fan turns on and the clutch enguages. I didnt leave it on for very long because im not sure if there is pressure there.

My question is, does the AC system have its own pressure sensor deactivating itself when the pressure is low? Because that might explain why it wont turn on by the switch. It does seem to have some pressure atleast because I pushed one of the fill ports and freon came out.

I do have a viewing glass on the other side of the engine bay, I didnt look at it tho because Im too scared to jump the system too long with no freon....that means burned out compressor.

[5thhorsemann]

I can tell you on the after market system that I removed from my 73 240 there were no sensors or failsafe devices in the wiring or plumbing. I use the older style 2-70 AC now. (2 windows down and drive 70 MPH)

[steve91tt]

Check the dryer. The aftermarket systems generally have a low pressure switch there. If you have power on one side of the switch and not the other (system on) then either a bad switch or low freon.

[71Nissan240Z]

Thanks, im probably gonna have to check the pressure with a guage, if its low im just going to rip out the ac. Im trying to lose some drag on the engine anyways.

[ZCCOR#109]

I would advise to seek out a good AC private tech to check your whole system.

I personally installed parts and pieces from "Vintage Air" in Texas to update my after market AC. http://www.vintageair.com/

I also updated the fan with the 1989 Honda blower. I kept the evaporator from the after market installed in 1973 as that is the "key" piece that is custom made for the Z. The rest (hoses, compressor, drier, condensor), are just standard AC pieces. My goal was to update to a 134a coolant system. Success!! However, one has to run the AC several times a year or the oil and fluid will leak out of the compressor as the seals will dry up!! :-(

Keep in mind that you can quickly remove the driving belt from the compressor by loosing the tension pully. I did that at every autocross back in the day. Takes three minutes max and no power loss.

Cold air is great.

[71Nissan240Z]

I would advise to seek out a good AC private tech to check your whole system.

I personally installed parts and pieces from "Vintage Air" in Texas to update my after market AC. http://www.vintageair.com/

I also updated the fan with the 1989 Honda blower. I kept the evaporator from the after market installed in 1973 as that is the "key" piece that is custom made for the Z. The rest (hoses, compressor, drier, condensor), are just standard AC pieces. My goal was to update to a 134a coolant system. Success!! However, one has to run the AC several times a year or the oil and fluid will leak out of the compressor as the seals will dry up!! :-(

Keep in mind that you can quickly remove the driving belt from the compressor by loosing the tension pully. I did that at every autocross back in the day. Takes three minutes max and no power loss.

Cold air is great.

The a/c doesnt blow cold, I already tried it. Im probably just going to gut it out and unhook it from the engine, ill use the fan to help cool the radiator.

[socal70Z]

Hi Lowell, Does that 1989 honda blower fit where the z car blower fits? I am thinking of doing the same thing. Thanks for any tips you might have about the process. Aaron near San Diego

[ZCCOR#109]

Hi Lowell, Does that 1989 honda blower fit where the z car blower fits? I am thinking of doing the same thing. Thanks for any tips you might have about the process. Aaron near San Diego

Yes, the 89 Honda fits. You have to modify the "gasket" or seal. AND, the fan turns the wrong way. You have to reverse the wires and the motor then turns the correct way...BUT the squirral cage blades are then not turned/curved the correct direction. However, even with the blades curved the wrong way, this motor pushes more air than the original. If one could find a squirral cage that would fit the shaft and have the blades turned the correct way. Wha...tornado I would think.

If the wires are wrong you won't get much air at all, as the "housing" is made for a particular direction of the fan rotation where by the air is "trapped" so it is moved forward only one way.

Edited July 23, 2011 by ZCCOR#109

[AZ-240z]

I was just going to rip the ac system out of my 71 Z. But seeing how everything is this and intact, it just doesnt turn on.

Ive traced the problem somwhere between the switch the the relay. The switch has no voltage with it on, so im assuming its the relay. Not sure tho.

Anyways, I found the power wire from the dash going to a tri connection close to the compressor. 1 wire going to the Fan (power), the other wire going to the compressor (power) and the wire coming from the dash.

I decided to just test the ac system by jumping the connection directly to the battery, the fan turns on and the clutch enguages. I didnt leave it on for very long because im not sure if there is pressure there.

My question is, does the AC system have its own pressure sensor deactivating itself when the pressure is low? Because that might explain why it wont turn on by the switch. It does seem to have some pressure atleast because I pushed one of the fill ports and freon came out.

I do have a viewing glass on the other side of the engine bay, I didnt look at it tho because Im too scared to jump the system too long with no freon....that means burned out compressor.

This may or may not be of any help, but I will tell you how my dealer added system originally worked when new. To turn the system on with the dealer added A/C control switch, the top slide OFF-VENT-HEAT control lever on the air control panel had to be in the OFF position which closed off airflow from the outside so air had to be drawn through the A/C condenser. If you were to find the vent closed by this lever on the upper right side of the blower motor/passenger foot well area, you would find a small micro-switch and contact which senses the action of this vent. I believe that this micro-switch closed the circuit between the dealer installed ON-OFF temp control switch and the compressor.

Electrics aren't my thing so this is a pretty rough explanation, but worth taking a look at. Too bad someone doesn't have a copy of the original installation proceedures that came with the aftermarket A/C systems.

Dan

[sblake01]

Too bad someone doesn't have a copy of the original installation proceedures that came with the aftermarket A/C systems.

Dan

Member 'madkaw' said he had one a while back in this thread that resufraced the other day. See post #7, maybe he still has it:

http://www.classiczcars.com/forums/showthread.php?27734-240Z-aftermarket-A-C-wiring-question.-HELP!&p=227610&viewfull=1#post227610

[socal70Z]

Thanks very much, good to know the important extra install info Lowell. Best wishes, Aaron

[hr369]

if you pull it out, would you want to sell me the compressor mount bracket

for the sanden compressor?