if i hear a highpitched whine/squeel, that means i have a hi pressure leak somewhere right?

i notice i slight coolant smell when i turn the heater on. im not sure if this is residual or if the heater core or orings are leaking or something. i havent really had time to notice wether or not im losing coolant. or at least im not losing it very fast. im thinking i may get some GM cooling sealant tabs to drop in . i just replaced my waterpump, housing, thermorstat, sensor etc, so it would be nice to get this done right while im doing it.

i noticed i get that squeel when i turn the heater on. also, i noticed it when the car is cut off when hot and allowed to cool.

i used a blacklight and i didnt see anything from the r134 or antifreeze

 

Anyone tell me how to read AC/heater codes ??? How do you get codes???

 

I tried it and could not get it to work. Tried several times. Just use OBDI if you have it.

 

Found out that on my 1995 850 Estate it has a diagnostic center under the hood near the windshield washer fluid fill. It not only does the OBDII codes but SRS, ABS and the Heating/AC. Why can't the other MFG's do the same thing. It's a bit primitive in that you need to count flashes to make up the code but it sure beats buying multiple two three or more hundred dollar code readers. I have a good OBDII reader (250.00) but I finally broke down and purchased a three hundred and twenty dollar OBDII with ABS reader. It still will not do SRS or Suspension codes and I have two Lincolns with air suspensions! ! !
So finding this diagnostic center I read the many Heat/AC codes and reset my SRS light after tripping it when I replaced the ignition switch. Needed to test drive to get the steering wheel centered after removing it. YUP< < I left the airbag disconnected during the test drive. Won't do that again.