[timrice]

Well, the fan finally quit working altogether.

I cut all four of the wires (BRN, BLU, GRN, and ORG) that run into the back of the climate control module on the dash. These wires are for the blower fan setting. I got rid of the old connector which had a couple of terminals melted into it, and put in a new Weather-Pack connector and terminals.

In the course of doing this, I found that someone had already spliced in a bypass for the BRN wire that runs under the dash and connects to the BRN wire on the module. That wire is OK. It has battery voltage on it, and I'm guessing it supplies the fan speed selector switch. After getting the new connector installed, I hooked it back up, and it still didn't blow on any setting. I disconnected the module, and bridged the BRN wire to each of the three others, and I got the LOW setting to work that way, but not the higher two settings.

I then dug under the relay and fuse panel on the firewall under the hood and pulled out the "blower control module" (??) This is basically just a flat plate with a 4-way connector on it, and you have three different-sized wire windings (resistances), that daisy-chain between the terminals. I measured these at 0.4 ohms, 0.5 ohms, and 2.7 ohms. (The idea being to drop the voltage applied to the motor down to one degree or another from battery level, thus modulating the speed?) I saw no opens, shorts, or corrosion, and the module's connector and terminals were in good order. While I had this off, I noticed that the terminal on the dark blue wire going to this resistance module had apparently gotten hot and melt-welded itself to the connector (like some of the wires I'd found under the dash), so I couldn't extract it. Nor could I extract the light-blue one next to it, though I didn't see any evidence of heat. The third wire, light brown, had a terminal that was not making good contact, so I straightened it out, and voila--I got my medium setting back. At this point, I have everything but the highest speed.

What I'm wondering is if that melted dark blue wire is the right circuit to be checking for the problem with the high-speed setting. It goes to the relay just above on the firewall that I know is the blower motor relay. A year or two ago when I was working on this same problem, I *thought* I was able to put battery power on the orange wire on that relay and the fan would run on high. When I do that now, the relay clicks OK, but the fan doesn't go.

I'm thinking I've ruled out any problems with my climate control module or fan selector switch in the dash. I don't know yet if I have a bad blower motor relay, or if that melty blue wire is part of my problem, or just what. (Hope it's not the relay, these don't look very "replaceable" since they're not the blade-terminal style that plug into a socket or relay block.) If anyone knows how to service / replace those, let me know. I've popped the top off, but all you see is the relay coil, not the wire connections. This relay has a black, blue, and orange wire (all 18 AWG). It also has a larger purple and a larger red wire (14 or 16 AWG). No doubt the red is battery supply. The purple goes to the fan motor terminal. I'm guessing the black is the relay coil's ground. I'm not clear on the blue and orange wire functions yet. (Seems like I had this figured out once and drew it up--but I can't find my diagram.)

So does the high-speed circuit go through that resistor module at all, or does it just get full juice by activating that blower motor relay and putting battery voltage across the motor terminals?

I'm assuming the fan motor itself is OK, since it will work on the lower settings--I'd think it'd work if given full juice direct from the battery.

Any advice on the operation of this system in general is appreciated.