This is how to build a comperssion tester for little money. Frist go to Pick a Part or something like that,find late GM A/C presser sensor and put it in your packet along with the connector. Go to Radio Shack and get the things you see inthe pic and with the wire dieagram piy it to gether.Find a scope or get one from some one you know (that's the high dollar item I didn't talk about).With a little shop air to calabrate in 5pis steps up to 160 you record the volteg and this is your chart. Thank you Mr.Wankelguy.For got A is ground B is 5v power C is signal and these are found on the connector , a 9v battery works quit well.

 

Gambone, you lost me with scope. what type of scope and where can it be purchased? thanks

 

Those look like one peice seals their..

 

oscilliscopes are expensive. 'better off buying a used one somewhere.

 

Im curious, have you tried this watching an osiliscope? did you have good results?

I ask this as I was thinking the same thing but was unable to find a presure sensor that was a potentiometer type. Most are on/off type sensors i.e. on at 65 psi off at 45 psi used in the A/C system.

What was the vehicle that had the sensor type you've found.

 

Same question here. GM part number ??

 

don't know the GM part no# just go to pick a part find a late GM 96 or newer and look for the 3 wire sensor on the high side of the AC line and follow the wire dieagram and use the A B C codes on the connector. Yes scope cost try to find a frend and use his or hers. Yes they are one pice apex seals and they are made of brass and they do work.

 

They look neat.

 

Yes they are one one peice seals ,the engine runs and come next rice day at Woodburn (local drag strip) I'll be there

 

Ill be their too.
Maybe Ill bring my 76 2dr Rx4 too.