Good morning. I own a 2003 Honda Element AWD MT. I've been having intermittent problems with the air conditioning system. When it works, it's great. When it doesn't, generally nothing works, no fans, no blower, no compressor clutch. If the system works when I start the car, it will work with no problems until I shut the car off. If I'm lucky, when I start the car again it will work, a lot of times it does not. Only the lights at the AC controller light up. In one occasion I heard the condenser fan work, but nothing else. Two separate times the blower was working, but no cooling, but most of the time the complete system is dead. The fans work properly when triggered by the coolant temperature switch. My troubleshooting found that the ground to the relays is lost when the system is acting up. The grounds come from the ECM/PCM. I cleaned the connectors at the ECM/PCM and the unit is mounted tight, checked connector C452, cleaned G101 ground. Any suggestions or prior experience with this?

 

welcome to the forum. no experience with your situation but have you checked plug connectors. some connectors/cannon plug (pins)work loose with heat or bad connections with heat. firewall forward.

 

Hi acmech52. I checked the connectors under the Under Hood Fuse and Relay box. Disconnected and reconnected. They looked good. I didn't check any others by the firewall, as the diagram does not show any others in there. I was wondering if there is anything that controls those grounds in the ECM/PCM externally.

 

sorry, my knowledge on ecm/pcm is 0. only experience were bad ground and loose connections, and pins backing out for bad contact or intermittent.