I'm working on our '00 Expedition's HVAC b/c the front blower will not come on. I found a test procedure to run and there is no power at the EATC blower speed control box, so the next step is to check for voltage b/t at the blower motor relay socket terminal, specifically terminal # 87 which is the black / light green wire, which according to the test procedure is supposed to be located in the center of the vehicle behind the dash. However, I had the main EATC unit, radio, and drivers side of dash off this afternoon and did not see the relay anywhere.
Hey MCM420 ... you said "I found a test procedure to run and there is no power at the EATC blower speed control box". What was the test procedure you used ... I have a similar issue.
tjweber, sorry it took me a few days to reply. I believe I was referring to a test procedure to see if power is going to the fan or fan controller. Mine turned out to be a bad power wire to the fan controller. The power wire is a fairly thick wire (about 8 - 10 gauge) and is brown with a yellow stripe. It originates somewhere around the steering column and runs over to the fan controller, which is close to the passenger side kick panel and the glove box. I had no power to it, but if I ran a hot wire from the battery to the fan itself, it would come on. So I knew it was most likely the wire feeding the fan controller. I ran a whole section of wire to the fan controller & haven't had any problems since. I really blame the wire going bad on the fan controller not being affixed to the glove box assembly. Somewhere along the line someone had a stereo or TV installed in the truck & must've knocked the fan controller loose. I stupidly let it hang there, not realizing the gold anodized bracket it's mounted to should've been secured to the side of the glove box assembly. What is your truck doing?