According to my diagram, fan motor power is supplied through the mode switch, whether equipped with A/C or not; if the fan resistor thermal fuse is blown, you're supposed to have HI still, as long as you're getting power through the mode switch. I would turn it on and go underhood to the fan resistor and check for power; if there's power, go to the motor (behind the right kick panel) and test for power and ground.
Currently, nothing at all happens when I use the switch. Not even HI, so I don't think it's the resistor. Could be the power or ground to the motor, though. I've never enjoyed electrical work, especially since so much of it is under the dash, requiring me to contort every which way. Also, sounds like I'll have to remove my crumbling gauge cluster yet again so I can get to the HVAC controls. Want to test the mode switch to see if the heater is getting power. And the A/C for that matter.
If it's not getting power to the resistor, that tells you if you even need to get into the dash or not. I mean, I do perform electrical work, but if it means I don't get my 6'6", 450# butt under and in the dash to make the repair, then I'm yards ahead.
I started at the mode switch, since that's where my suspicions were strongest. Removed the connector from the back, and it had voltage going to it. Jumped across it and the blower came on. So, I removed the HVAC controls and started poking around. I was greeted by this. The silver colored contact was separated, probably from overheating since some plastic was slightly melted. Ended up stuffing a jumper wire in the connector, bypassing the shut-off switch entirely. Now the blower works almost normally, just doesn't turn off by moving the controls to OFF. I'll refrain from blasting the blower on HI, considering the melting in the connector and what not.
Yeah, some Ford connectors have a tendency to overheat from too much amperage, especially when you have a loose connection. I tighten up the terminal in the connector to make less resistance, unless the terminals are actually burned, then replacement is warranted.
Got a replacement control unit on the way. Hopefully it doesn't have the same problem. Really don't want to have to also replace the connector as well, if that turns out to be contributing to the problem.
Can you snap and post a pic of the business end? We can take a look, see if there's something we see you may not realize is a problem.
Well then. Maybe I can get the new pigtail, figure out how to depin the new and old one, then swap over the new connector housing to the old wires. Hopefully all the varnish and crap in the fuel tank will work its way out of the system soon. Fouled up the #1 plug something fierce, and the engine pings at certain points. Think the carb is getting clogged up. Time for another filter. I may also do an AOD conversion when I pull the motor. Seems pretty straightforward. The engine needs to come out to get resealed, then I'll toss a set of E7s I have laying around on there and the camshaft from my Mustang. I'm not expecting a whole lot of power, but more than 200 would be nice.
You can buy a kit of terminals and a crimper to do it that way, or find a used one (when I say 'pigtail,' I refer to the connector with the terminated wire ends and a fair length of wire on them; you just splice the wires together) and install it. Since this has come up, and I haven't yet finished buttoning up the dash, I'm going to pull that connector and and the fan switch connector and inspect them.
Exhaust is installed! Sounds pretty good to me. Though at the end, you can hear it starting to misfire. I'm kinda thinking that maybe it's the Duraspark. And the No. 6 cylinder started misfiring at idle. Tested them all with a timing light to see which ones failed to fire. I'll pull the No. 6 plug tomorrow. Checked them all earlier today, and they looked fine, aside from several of them being red. That might be some of the varnished fuel. But I can hardly get over 1/4 throttle before it starts misfiring, and 45 mph without missing on flat ground is a challenge. Replaced the fuel filter last night, and added another one as well, just to be sure. Sometimes it'll work, sometimes it won't. Like, full throttle in 2nd at 60 going uphill might clear it enough so it'll cough back to life and then drive as expected; or it'll spontaneously work for a trip, then it'll be back to missing the next trip. P.S., the distributor only has vacuum advance. No mechanical advance.
There you are. You have to have all three types of advance--initial, centrifugal and vacuum, properly set--to not have bad performance/misfiring, and the varnished gas isn't helping at all. Do you have a replacement dizzy? If not, have you attempted to lubricate the mechanical advance weights and shaft?
I do not yet have a replacement distributor. I'll pull it at some point to inspect it (apparently it probably does have mechanical advance, but I didn't see it [likely hidden under everything else]). I didn't notice any advance taking place with a timing light, so it'll likely need lubrication. The Duraspark module will get taken to Autozone to be tested, just to confirm that it's working. If not, I'll replace it with an MSD box. But yeah, it feels like I'm hitting a rev limiter after a certain loading.
Making it work is simple, really--pull the rotor, and the shaft end should have a felt pad inside, it holds oil. Pick that pad out and spray some penetrating oil into the top of the shaft, then put the pad back in and put a few drops of engine oil into the pad. Then, there's a square hole in the plate the pickup coil rides on; bump the engine, or bar it over, till you see the spring 'stanchion' under the plate. Take the spray tube and gently spray penetrating oil down that square hole, toward the shaft. Do it for each side of the centrifugal weights, and unless you have an actual mechanical problem (top of shaft frozen with rust, mechanical weights rusted or locked in place, etc.), this action should go a long way.
Did some testing last night, and found that the vacuum canister wasn't holding vacuum. Put a plug on the ported vacuum, and the thing will at least rev and get up to speed. Checked the mechanical advance (didn't lube it just yet), and it did work. Maybe only 5 degrees of advance or so. Still misses and runs poorly at idle and low load/low speed. I'll try lubing the dizzy. Still gotta test the Duraspark module.
Honestly, the Duraspark is a pass/fail. If you're getting random misfiring, you should be looking at the coil, wires and cap.
The wires and cap are new. The coil is a used one from my Mustang, but it's pretty old. I was thinking about that on the way in to work today. Maybe I'll toss an MSD coil at it for a mild upgrade and a possible fix.
Do you have a DMM? Having new parts is nice, but throwing parts at a problem is exhausting. The coil spec is as follows: Primary winding 1.5 ohms,. +/- .25 ohm Secondary winding 8K-11K ohms, and should be checked both cold and hot when the coil is suspected.
I'll test it out when I get the chance. It's kinda behaving like it did before I changed it out the first time, so I'm about 65% sure that it's the coil.