May be why the air doesn’t work...

[84 Shorty]

The only thing that I havnt checked is the fan speed switch and blower control switch on the control panel. I did some reading and found sometimes those can be faulty. That would explain why everything is good from the junction box over in engine compartment. I will look shortly, hopefully that’s the issue.

 

[84 Shorty]

Really Andrew, 2X what HKJ says. You have dropped in a complete engine compartment harness, and spliced it into the cab harness the right way (i.e. by soldering/heat shrinking the connections). Then you proved that the entire system will work as designed - by supplying the control panel with an external power source. If you can do all that in one day, you can surely figure out why there is no power from the fuse block to the end of a single wire less than 3 feet away.

If you don't want to tear into your loom/fuse block, just run a new lead (again as HJK says, with an in-line fuse). Tap into the front of the block and run the wire straight over to the pigtail on the mode control harness plug. Use the ACC switched power jack adjacent to the radio fuse. It will be wired exactly the same (schematically speaking) as if you were using the factory wiring and the blocked mounted HTR fuse:

You must be registered for see images attach

What size inline fuse would you run? 25 amp?

 

[84 Shorty]

Looks like it burnt clear through? Could this be the Culprit?

You must be registered for see images attach

 

[Honky Kong jr]

What size inline fuse would you run? 25 amp?

15 you want it to blow quick so it doesn’t let the smoke out of anything.

 

[84 Shorty]

15 you want it to blow quick so it doesn’t let the smoke out of anything.

I’m going to order a new switch, looks like it got a little toasty. If that doesn’t fix the problem I will run an inline fuse to this solid brown wire.

You must be registered for see images attach

 

[chengny]

I’m going to order a new switch, looks like it got a little toasty. If that doesn’t fix the problem I will run an inline fuse to this solid brown wire.

Even if the mode switch is burnt - and is not able to send power over to the fan speed switch - replacing it won't restore blower function...unless there is power available on the BRN 50 feed from the fuse block. Did you have any luck diagnosing why there is no voltage on the BRN 50 power supply to the mode select switch?

After replacing the HTR fuse, did you actually confirm voltage at the BRN 50 connector on the harness side - or did you just plug it into the switch pigtail and test the system?

BTW, you never mentioned - on that HTR fuse; did you even find one installed? And if there was a fuse in that slot, was blown or did it appear to be good?

 

[84 Shorty]

Even if the mode switch is burnt - and is not able to send power over to the fan speed switch - replacing it won't restore blower function...unless there is power available on the BRN 50 feed from the fuse block. Did you have any luck diagnosing why there is no voltage on the BRN 50 power supply to the mode select switch?

After replacing the HTR fuse, did you actually confirm voltage at the BRN 50 connector on the harness side - or did you just plug it into the switch pigtail and test the system?

BTW, you never mentioned - on that HTR fuse; did you even find one installed? And if there was a fuse in that slot, was blown or did it appear to be good?

I checked the brown wire directly from the harness it has 12V. Heater fuse was there, it was blown so I replaced it.

You must be registered for see images attach

 

[gmachinz]

More than likely that 15 amp fuse probably blew because the blower motor is wearing out which draws too much current. Also, that 16ga wire is really undersized imo for that entire blower circuit. Obviously medium-high is the highest speed that wire sees but keep in mind that amperage may originate from the fuse panel but it has to travel:

fuse panel-blower speed switch-blower resistor pack-blower motor.

There is quite a bit of voltage loss from beginning to end coupled with a high drawing older blower motor it all adds up to more heat in the wiring and the plastic connector in the back of the climate control unit is the weakest link in the system. It should have been made from the same high density polyethylene plastic like headlight connectors but wasnt. To combat the high resistance aspect of it I like to upgrade to at least a 14ga wire if not a 12ga feed from fuse panel to climate control connector-just something to think about.

 

[gmachinz]

And that wire is only an acrylic jacketed type too-not rated for high heat, which over time as I outlined that blower speed feed wire can get pretty damn warm.

 

[84 Shorty]

The new selector switch came in tonight. Going to get the dash back together and harnesses attached. Brown wire has power from fuse panel, good fuse, and everything powered from the junction box to blower motor. Fingers crossed I can get this **** working.

 

[Honky Kong jr]

The new selector switch came in tonight. Going to get the dash back together and harnesses attached. Brown wire has power from fuse panel, good fuse, and everything powered from the junction box to blower motor. Fingers crossed I can get this **** working.

Hope it works out for ya

 

[84 Shorty]

Hope it works out for ya

**** by the time I get the heat working I’ll need the A/C

 

[Honky Kong jr]

**** by the time I get the heat working I’ll need the A/C

I was impressed when I saw the pic of your meter

 

[84 Shorty]

I was impressed when I saw the pic of your meter

Yea, I even impressed myself. I knew I bought it for some reason, first time using it.

 

[CSFJ]

It's not how often you use it, it's that you know how to use it and have it for when you need it.