Cigarette lighter wiring/fuse 12 meldown/heater issues

[MindBender0001]

I'll try to make this as simple of an explanation as possible, but I may ramble, so I apologize in advance.

I'm working on my wife's '94 Explorer XLT. No power seats. The problem I had initially was a temperamental blower motor. It worked when it wanted to. We went for a drive to get a power driver's bucket seat and my wife pointed out how hot the face of the heater control panel gets. You couldn't keep your hand on it, it was so hot. I pulled the ashtray out (can't remember why ATM) and found both the hot and ground to the lighter were melted. Melted enough that the ground side was just bare wire. It still worked, as did the heater. I disconnected the lighter's ground wire and the end broke off in my hand. However unrelated it seems, the heater ALSO stopped working after I disconnected the wire.

Now I'm tearing into this issue, and I find that the connector to the blower motor switch was also melted, mostly at the top black (ground) wire. Didn't make much sense, but after reading in these forums I found the heater switch works through the ground and the resistor pack. I replaced both the connector (none of these wires were melted, just the plastic plug housing), the blower switch, and the blower switch relay. The 50A blower fuse was (and still is) good. When the heater WOULD work, it worked on all speeds, so I didn't (and haven't) checked the blower motor itself or the resistor pack. After replacing all these parts, no blower.

I moved to the interior fuse block thinking MAYBE a smaller fuse puts power to the blower relay. In the interior fuse block, the plastic around fuse 12 is melted, and the fuse is blown. I put another one in and it blew as soon as it made contact. That tells me there is probably a direct short somewhere. Since I had the dash bezel off, I was able to see the wires going into the back of the fuse block. I can see a blue/white stripe wire (same as what's melted for the cigarette lighter), and its all shiny while the other wires are 'flat'. As I dig a bit deeper, I find the wires (same color scheme and shiny, so I assume the cigarette lighter wires) melted together with some other wires on the back of the fuse box.

Also, the two vacuum lines to the heater controls are probably compromised at one or more locations. What would be the harm in just 'pinching' these two off? I have no idea where they go or what they control.

So, now I'm open to options. I just looked up how to pull the dash out, and it doesn't look that bad. I have NO qualms with the cigarette lighter never working, but how can this also be tied to the heater???!!! If need be, can I just cut the wires off the back of the fuse box and run some new ones (with fuses of course) to get the blower motor to work again? I've looked up the wiring diagram in my Chilton manual, and there is no cigarette lighter, so I can't find where these two systems may in fact be tied together.

As a side note, I also need to replace the windshield nozzle on the passenger side. My manual says to remove the screws holding the cowling down, but our x's cowl is welded (factory) to the firewall!!!! While at the wrecking yard, I found a '92 that had an access panel right below the passenger nozzle, but from '93-on, no access panel. Anyone else have to replace this, specifically on a '94 and how the hell did you do it?!?! For now, I'm gonna pinch off the hose to that nozzle so at least the driver's side can actually do its job. Won't be the whole windshield, but it'll be better that what she has now.

 

[MindBender0001]

K. I feel like a dumba$$. The wife comes home, I explain to her what I did, and she says: "So put the old relay back in and see what happens.". Sheesh. What does she know. I tried it. It worked. Now the blower motor works. As it turns out, fuse 12 is for the cigarette lighter and the flash-to-pass. Don't need either, so I'm leaving that can o worms alone.