I recently replaced the heater core (it blew) in my 96 Escort. Of course it requires removing the steering wheel, dashboard and everything else in the front cabin. Following the replacement and re-installation I began testing everything. For the most part everything works except the radio speakers, the Air Conditioning and now there is a noise that almost sounds like a small exhaust leak (chugging noise) when the car is in gear only. The noise gets worse as I accelerate and increase the load on the engine and transmission. The noise goes away when maintaining speed or coasting. Furthermore, while driving to work yesterday the check engine light came on. The air conditioner compressor clutch will not engage at all. I don't think it is due to low r-134 because it worked fine before the dashboard pull. I read on some forums to disconnect the battery for 5-10 mins and did so. Now the check engine light is off, so I probably reset any codes that were there. Oooops! At any rate I am baffled.
I have a few suspicions......
1. Perhaps I failed to thoroughly 'click' all the connectors when I put the dashboard back in. I am considering removing and starting over while carefully checking each connector.
2. Some antifreeze leaked onto the EEC module (I think) that is located directly under the heater core/venting assembly. I can understand why this may affect the compressor clutch and possibly the noise, but not the radio speakers. The radio powers up fine, but no sound. I'm not too worried about it. My major concerns are that noise and the a/c. I hope I don't have to replace that EEC module.
3. Following heater core replacement, I sprayed some water in the engine compartment (while engine was still cool) to remove some of the antifreeze that splashed around when I disconnected the heater core hoses. I'm concerned that perhaps some water annoyed the a/c compressor clutch switch located near the firewall or an a/c relay that I can't locate.
I guess I am asking for any thoughts and perhaps some information that would point me to a website that shows where all the A/C components are located in the car. I have a haynes manual that shows the electrical diagram, but it doesn't show the actual location of the various relays, switches etc...for the a/c system. BTW the blower unit works fine and the little blue a/c light on the environmental control slider works fine.