easy queston

[kglowacky]

I just got all my wiring for my ac/heater unit figured out. Two easy questions on GM wiring terminology . I have a wire going to "Junction Block" and a Wire going to "Fuse block Cavity"

The Fuse Block Cavity is a 14 gauge wire solid brown in color. I think it goes to ignition power on the fuse box. Coming off the selector switch

The Junction block is a 12 gauge red wire and I think it connects to 12v hot with a breaker in between. The reason is for this thought is my wire has a factory eye connector on the end. Coming off the blower relay

Are these correct

[kglowacky]

1978 c-10

two questions someone confirm my assumptions on what gm called junction block and Fuse block cavity

[mongocanfly]

Junction block...
https://www.classicparts.com/1973-91...xoCIiQQAvD_BwE


fuse block cavity....Google keeps showing the fuse block....

[kglowacky]

I bought this truck in parts and sure enough I do have one of those junction blocks in a box of parts. LOL bought a 5 stud one to do my LS 1 swap so I will just hook to it. Looks like constant power to this block. Thanks

[rodstored-72]

Originally Posted by kglowacky

I bought this truck in parts and sure enough I do have one of those junction blocks in a box of parts. LOL bought a 5 stud one to do my LS 1 swap so I will just hook to it. Looks like constant power to this block. Thanks

sounds right from what I was able to figure for my build and pics I took before I started dis-assymbly as well - the block is constant power. I had a red wire running from the batt. directly to the junction box.
good luck!!

[kglowacky]

thanks for the confirmation. I figure that red hot wire is the direct power (via the factory relay) to the blower motor. My challenge is the other wire that trips the factory relay. I was thinking it was the solid brown wire from the back of the fan switch that went to a ignition hot so when you turned on the fan switch it opened the relay and the blower would run with direct power from the red hot battery wire. Well when I connect the brown wire it blows the fuse instantly . So Iam back to trying to figure out what wire trips the relay.


Update: just solved my problem.. First the solid Brown wire coming off the back of the fan switch is in fact Ignition power. The reason I was blowing fuses instantly was my blower relay was rusted so bad it had rusted the top of the relay to the top of the relay case so it was grounded so when I threw power to it (Connecting the brown wire) it was a dead short. Went and bought a new relay and works like it is suppose to. I took the relay apart to find this rust issue. I hope these threads I am doing will help someone in the future. Thanks for everyone's help.