Air con problem

Question

my A/c technician pulled-out the A/C relay, test probe the A/C relay socket and found out that one line which receives signal from the computer box(ECM) is open since his test probe light is out. he told me that there might be a problem on my ECM since the compressor is running when i turn on the air con but no cool air is coming out of the vents. Is there really a line from the relay that is connected to the computer box or that receives signal from the computer box?
To Ronaldo: i really appreciate your response but what do you mean by " blend door problem"?

Answer 1

You should have a tech with more experience check the A/C system for you.

Firstable you are not suppose to check signal from Engine Control Module (ECM) with a test light, you have to use a volt meter to do it and not a test light, you could damage the ECM with a test light.

Yes, there is a signal from ECM to the relay, but if there is no signal, it doesn't mean that the ECM is bad. There are many things that could cause a no signal situation from the ECM.

Comments

Thanks for the response. Have my car checked by an auto electrician and he found out that the line from the relay is connected to the A/C switch. The line is open so he just replaced the open line wire with a new wire and the A/C produces its cool air.