Electrical genius advice needed,....

[Rudy Mienert]

Hello, problem for the week,....For starters, 78 Blazer bought with no engine/trans, and i swapped in a 5.3. All works, except the fusebox has no power to the wiper and radio fuse locations. I'm wracking my brain trying to figure what feeds these two, and how to diagnose what went wrong,...Any advice will be appreciated!!

 

[Snoots]

Fusible link from the junction block on the firewall to the firewall side of the fuse block.

 

[Doppleganger]

Wipers and radio are on the ignition side....iirc.

 

[CalSgt]

Wipers and radio are on the ignition side....iirc.

This sounds right, the older truck wipers would not "park" themselves when the key was switched off, they just stopped mid wipe.

With the Key turned to "run" do you have power at any of the unused slots labeled "IGN"

It could be a bad ignition switch itself. There should be heavy gauge red, yellow, orange and pink wires at the ignition switch but I cant remember which one is the feed for the fusebox to test.

 

[WP29P4A]

If you don't already have a test light, get one. They are not expensive and they are so much easier to use quickly than a multi-meter. This one displays voltage and lights up, for less than $20.

 

[Rudy Mienert]

Fusible link from the junction block on the firewall to the firewall side of the fuse block.

my theory, also,...I do have and used a test light on the fuse box, neither side of the fuse holders have power in the on position. I hate throwing parts at problems, and hoping for the best, but I may pop in an ignition switch. Thanks to all you guys for helping,.....any other ideas would also be appreciated...

 

[Juggernaut]

Check the bulkhead connector, make sure the block is fully seated and the screw is tight

 

[MikeB]

I don't know about a 78, but an 82 has two 12 volt feed wires running through the bulkhead connector to the fuse panel. They are two large diameter red wires. (My 82 used metric wires that were somewhere between 10 and 12 gauge.) Anyway, make sure you have 12 volts on those wires.

 

[Rudy Mienert]

Thanks to all who helped!! I did track down the problem and it was due to "human error",...I am that human, LOL,...it was in the ignition switch on the column,..when I clipped in the harness to the switch, I did not notice one male connector (12g brown wire) bent outwards as I connected it. I love when I find and correct a problem, but I hate when I caused it.

 

[Rudy Mienert]

This sounds right, the older truck wipers would not "park" themselves when the key was switched off, they just stopped mid wipe.

With the Key turned to "run" do you have power at any of the unused slots labeled "IGN"

It could be a bad ignition switch itself. There should be heavy gauge red, yellow, orange and pink wires at the ignition switch but I cant remember which one is the feed for the fusebox to test.

you led me in the right direction, thanks!!!