Junction block on firewall

[robert8096]

On my 74 shortbed there is a junction block located on the fire wall that looks to feed power to the AC/Heater box. Is this the only thing the block feeds?
I ask because I want the clean up the firewall and want to run the wires for the engine lower on the wall. My plans are to replace the AC/Heater system with a Vintage Air system.

 

[foamypirate]

On my 84' the power feed into the fuseblock for the cab was connected to the junction block.

 

[89Suburban]

The wires going to the junction block have nothing to do with the heater control wire harness. The heavy orange wire coming out of the cab for the heater controls go to the resistor bolted to the blower housing, along with a few other wires. Power for the blower originates from the fuse block and get's fed through the fan speed selector switch and into that resistor then one wire runs to the blower motor.

I highlighted it for you here:

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[robert8096]

On my 84' the power feed into the fuseblock for the cab was connected to the junction block.

On this 74 the fuseblock is being fed thru the yellow wire coming off the alternator connector. On my 86 the wire that feeds the fusebox comes up from the starter thru a fusible link to the junction block and then to the fusebox.

The wires going to the junction block have nothing to do with the heater control wire harness. The heavy orange wire coming out of the cab for the heater controls go to the resistor bolted to the blower housing, along with a few other wires. Power for the blower originates from the fuse block and get's fed through the fan speed selector switch and into that resistor then one wire runs to the blower motor.

On my 86 that is correct. On the 74 the red wire on the junction block comes from the battery lug on the starter then thru the glass fuse holder to the orange wire which feeds the blower. There are no splices in the orange wire from one side of fuse holder to the connector. It makes me think and looks like it was a factory setup.

Maybe I have some creative wiring going on.

 

[89Suburban]

On this 74 the fuseblock is being fed thru the yellow wire coming off the alternator connector. On my 86 the wire that feeds the fusebox comes up from the starter thru a fusible link to the junction block and then to the fusebox.




On my 86 that is correct. On the 74 the red wire on the junction block comes from the battery lug on the starter then thru the glass fuse holder to the orange wire which feeds the blower. There are no splices in the orange wire from one side of fuse holder to the connector. It makes me think and looks like it was a factory setup.

Maybe I have some creative wiring going on.

Yup you are correct. I was only looking at the 86 diagram. So there are instances of that setup. I even saw it on the 1990 diagram and made a copy of it to post here once I can find the damned time to get onto my laptop.