Electrical Prob, Need help ASAP Please, K5's Dead

[Big Blzn]

Pics are attached. First I know very little about truck electrical systems. So, I'm trying to find out why my auto oil cooler fan is not turning on as I believe it should when it gets hot enough. In the first pic it shows a 12v "relay switch" with three prongs that is attached to wires on the relay switch in the second pic. The second pic has power to it, I know because my tester says so. I didn't seem to get power from the relay it the first pic though. Then, I touched the tester to the middle stud on the 12v relay that has a "B" nest to the stud, it sparked pretty good and then the engine on the K5 shut off and won't even turn over now. All the fuses in the fuse panel are good. The relay in the 2nd pic still has power. Could I have fried the 12v relay? Please help. Sh!t like this reeeeeeeeeeeeeeeeeaaaaaaaaaallllllllly bothers me because of my lack of knowledg



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[hidesertwheelin]

Check you fuseable links. They should be located near your starter.

 

[Big Blzn]

An auto parts guy said the same thing about the fuseable link. The starter is in such a cramped location is it only possible to check and change this fuseable link is by removing the headers? I sure hope not.

 

[ryoken]

shouldn't be.. disconnect the wires from the starter and pull them up and out so you can check..

i never reinstall em.. your better off just running a new wire up to a spot on the firewall and putting a fuse or breaker so its accessable...

 

[dyeager535]

You don't HAVE to pull them off the starter to test. The fusible link wires run up to the junction block on the firewall drivers side of the distributor. Two metal studs protected by plastic ears. If you don't have power there, but have power at the battery, either your battery cables are bad, or the wires from the starter solenoid to that junction block are bad.

As you were told, fusible links are the likely culprit if you don't have power to the junction block.

Ugh, just noticed this is a '72, no idea if they ran that junction block or not. They did on most if not all later ones.

 

[diesel4me]

similar...

Pre-72 trucks used a similar junction block ,but its next to the battery...they put the fusible links on older years right onto the positive battery cable near the battery,or at the junction block..

I always remove them (fuseible links)from the starter solenoid, and put them to the positive cable instead..its too difficult to fix blown fusible links ,the way GM hides them in that stupid metal conduit that gets roasting hot from the exhaust manifold..why they decided to ever move them there is beyond me..sometimes you need to lengthen the wires to reach the battery,but its worth doing..if and when you pop another fusible link,you can change it in minutes,not hours!..

 

[Big Blzn]

shouldn't be.. disconnect the wires from the starter and pull them up and out so you can check..

i never reinstall em.. your better off just running a new wire up to a spot on the firewall and putting a fuse or breaker so its accessable...

So here's where I'm at. Took all the wires off the starterand unwrapped them from their elcetrical tape etc. I couldn't find any type of thing that would indicate it to be a fuseable link, anywhere. I kept testing everything to see if it power ie alternator, other relays, anything I could think of. The first several times I tested the small yellow wire that attaches to the small stud on the starter and it showed I had power, then I tested again and had power to it, WTF. Maybe I had a bad ground while testing it? So I connected the yellow and purple back to the starter and the engine started right up, again WTF. My concern is that I didn't change or replace anything that would have solved the original problem and I don't want to be driving or what not and have it just not start or die on me while on the road. Guess I better make sure my AAA is current and paid.

Ryoken, since I didn't find any fuseable links, is it possible that the prior owner didn't use any or would the truck just not run without them? What type of fuse should I put up on the fire wall to have a safety factor? What amp fuse or style should I use? Do I just incorporate the yellow wire or both the yellow and purple for the fuse?

Thanks for all your help in advance.

 

[bear76]

A 30amp fuse should be good. Just get the inline spade type fuse at the part store. Mount it on the firewall for easy access.

Edit*

If it were me I would get a small fuse block (6 fuses) and start running things through it as needed. Makes life better not having to trace links around.

 

[Big Blzn]

A 30amp fuse should be good. Just get the inline spade type fuse at the part store. Mount it on the firewall for easy access.

Edit*

If it were me I would get a small fuse block (6 fuses) and start running things through it as needed. Makes life better not having to trace links around.

Good point. Thanks for the input.