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My ac stopped blowing cold in my 98 C5. It was low on refrigerant, so I added some. The clutch still will not engage so that I can get the pressure right. Any ideas?
Since I do not have knowledge of AC issues and how to fix them after many previous goofs, I now go to the experts to let them sort out any cooling issues.
Since I do not have knowledge of AC issues and how to fix them after many previous goofs, I now go to the experts to let them sort out any cooling issues.
Do you have a 12 volt test light and know how to use one ??…can be an easy diagnosis…you can check Fuse 24 and try swapping AC Clutch relay 34 with the horn relay…if this isn’t above your ability you can jumper the load side of the relay which is terminals 87 and 30…if this works and clutch engages you have a control side issue on the relay…the PCM grounds the control side of the relay which are terminals 86 and 85…if the PCM is not grounding terminal 85 you can use the test light to provide a ground for the relay…if it works with a test light you then check the wire AT the PCM…there are inputs that allow the clutch to engage if everything but the AC Control is not providing the ground…ambient temp sensor, AC Pressure Sensor and probably 1 or 2 I forgot…if this is above your abilities bring the car to an auto electric shop in your area…they will be better to diagnose this !!
Do you have a 12 volt test light and know how to use one ??…can be an easy diagnosis…you can check Fuse 24 and try swapping AC Clutch relay 34 with the horn relay…if this isn’t above your ability you can jumper the load side of the relay which is terminals 87 and 30…if this works and clutch engages you have a control side issue on the relay…the PCM grounds the control side of the relay which are terminals 86 and 85…if the PCM is not grounding terminal 85 you can use the test light to provide a ground for the relay…if it works with a test light you then check the wire AT the PCM…there are inputs that allow the clutch to engage…ambient temp sensor, AC Pressure Sensor and probably 1 or 2 I forgot…if this is above your abilities bring the car to an auto electric shop in your area…they will be better to diagnose this !!
I’m capable, may have further questions, but I know my way around a multimeter (in school for electrician). Thank you, I will try this and get back to you.
I’m capable, may have further questions, but I know my way around a multimeter (in school for electrician). Thank you, I will try this and get back to you.
Electrician and automotive electrical are almost the same !!
My ac stopped blowing cold in my 98 C5. It was low on refrigerant, so I added some. The clutch still will not engage so that I can get the pressure right. Any ideas?
Low charge is one of the most common reasons for no a/c but there are other sensor/electrical reasons.
Have you put a gage set on to see if your system has any pressure? If it has not lost all its charge, you really cannot add charge by hooking up a can of R134a unless you were to heat it which is a bad idea.
If your system still has some pressure, you can force the system to take charge by jumping the clutch but just be aware there is very little lubrication of the compressor until you get enough charge to go in to the point where the system can run without jumping the compressor.
If your system has lost all its charge, you have a pretty substantial leak and your system is contaminated with air. Forcing charge into an air contaminated system is a bad idea.
Either way, if low charge is the reason for loss of a/c, you are on borrowed time until it leaks out again.
MMM ??…see if you have power on terminal 30 which is load side feed…if so take the 12 volt test light connected to battery positive and probe terminal 87 which goes down to the relay…the test light should illuminate as it checks power through the coil clutch and then to ground G102.
MMM ??…see if you have power on terminal 30 which is load side feed…if so take the 12 volt test light connected to battery positive and probe terminal 87 which goes down to the relay…the test light should illuminate as it checks power through the coil clutch and then to ground G102.
05-09-2024, 05:17 PM
AC Compressor Clutch will not engage.
