70 C20 no power!! HELP!!

[DEESTER157]

So I’ve got a 70 Model C20 that did not have an ignition or starter when I purchased it. Bought everything for the ignition and wired it up, bolted the starter on and wired it up, then hooked up a good battery and.....nothing! No headlights, dash lights, or any power at all inside the cab or anywhere. I have no idea why. On my starter I’ve got the hot wire that goes to my positive battery terminal hooked to my big post on the starter, yellow wire going to the R side(small post), and purple going to the S side(small post). Should there be anything else hooked to the big post besides my positive wire that goes straight to the battery? It’s like I have no power to my harness. What else could my problem be? If everything is hooked up right then is it possible that the positive wire is bad and I’m not getting juice down to the starter? I don’t see any other wires that could be hooked to the big post on my starter. Please let me know what y’all think. Thanks

[kwmech]

12v wire should come from the battery to the right fender electrical block. From there it winds around the core support to the firewall junction block after it ties in with the charge wire from the alt. Get a test light

[VetteVet]

here's a diagram of the stock wiring in the engine compartment showing the battery to starter to alternator connections. It also shows the wiring to the rest of the engine compartment components.






Here's the wiring to the alternator and regulator to show the charging system.



The small wire labeled "fusible link" carries all the battery power to the charging system and the cab power for the lights and key switch and the fuse panel. You must have that to get juice to the truck components and it protects them from shorts and possible fires and damage.

[DEESTER157]

Ok well that makes sense. I knew I had to be missing something. I’ll have to look at it this evening and see what I got. In the wire with the fusible link, what fuse should I put in there? Thanks

[DEESTER157]

Also on the harness that goes down to my starter, I have purple and yellow witch shows on the diagram but I also have a light green and dark green feeding down to my starter and I do not see this on the diagram. Any idea what these are for? Thanks

[LockDoc]

Originally Posted by DEESTER157

Ok well that makes sense. I knew I had to be missing something. I’ll have to look at it this evening and see what I got. In the wire with the fusible link, what fuse should I put in there? Thanks

There isn't a fuse in the fusible link. Here is an explanation of a fusible link....

"A fusible link acts much like a fuse, only it’s designed to handle a different type of potentially hazardous scenario. These links are actually strands of wire wrapped in a fireproof covering, and are thinner than the wiring harnesses they’re connected to. They are placed in-line between delicate harnesses and large sources of electrical current in your car—between the battery and alternator, for example. These links must transmit high-voltage electricity, but also protect the rest of the electrical system from dangerous spikes that could cause a fire. If there’s a surge, the link actually melts, as its resistance to heat is lower than that of the circuits it’s protecting. This cuts off power while protecting the engine bay from a conflagration, thanks to its fireproof wrapping."

You should be able to get one at an auto parts store. You will need to provide the parts guy the application you are using it on to make sure you get the correct one. Many times on these old trucks the fusible link will have been replaced with a regular wire. NOT a good idea.....

LockDoc

[DEESTER157]

Thanks for the diagrams and replies guys and thanks for the fuseable link def Lock! That makes perfect sense. Ill have to pick one up on my way home today. I think that solves that problem. Does anybody have any idea what the light green and dark green wires are that go down to my starter are? Thanks

[demian5]

Originally Posted by DEESTER157

Thanks for the diagrams and replies guys and thanks for the fuseable link def Lock! That makes perfect sense. Ill have to pick one up on my way home today. I think that solves that problem. Does anybody have any idea what the light green and dark green wires are that go down to my starter are? Thanks

One is the signal wire from the ignition switch to activate the starter, the other comes up to the coil to power the ignition I believe.

[A1971Blazer]

Originally Posted by DEESTER157

Thanks for the diagrams and replies guys and thanks for the fuseable link def Lock! That makes perfect sense. Ill have to pick one up on my way home today. I think that solves that problem. Does anybody have any idea what the light green and dark green wires are that go down to my starter are? Thanks

if they're the factory wires...the light green and dark green are for the backup lights....they shouldn't be attached to the starter...anywhere...

[demian5]

Check the nut on the black junction box on the passenger fender and clean it first. Make sure you get power there.

[A1971Blazer]

Not sure about these....but many manuals have the safety switch mounted to the clutch bracket....thereby preventing a start up unless the clutch pedal is depressed...

[DEESTER157]

Ok, I’ll have to look and see if i have a switch on the column. I’ve also still got the clutch pedal and stuff installed so I’ll have to look and see if it may be mounted there. Would this be inside the cab on the clutch bracket/pedal? Thanks