1990 Acura Legend

A friend of mine just bought a car alarm from a Car Alarm/Car Stereo store. After they installed it, his heater stopped working. He said he was using the heater when he drove to the place. He said he turned around and went back to show them the problem. After the tech (same person that did the install) looked around a bit, they told my friend that the heater could've been broke before their install and it wasn't their responsibility to fix it. So he brought the car to me to look at because I know a little about installing stereos and 12 volt troubleshooting. By no means am I an expert. I checked all fuses and all are good. The heater does blow air, but doesn't get hot. Also, there is a clicking sound around the glove box while air is blowing. The Heater Control Panel is the LS model. I did notice 3 wires that they tapped off of from the alarm. One wire is black/yellow, I believe another was blue/white, and I don't remember the other. Any advice would be great.
December 3, 2012.

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