1972 C20 will not start/seems like no electic power
 

I'm requesting some help with my 1972 C20 truck (350 engine/400 trans). I started it 3 days ago and didn't have any issues when I moved it. I went to move it yesterday to pull off the bed for repairs and now it will not do anything.

An when I say anything, I mean nothing - the lights will not come on, the brake lights do not light, the wipers don't move, the starter doesn't try to engage and/or there is no clicking like the battery is dead. I checked all the glass fuses on the block and they are all showing good.

I took a volt meter and have 12.8v at the battery, I followed it out to a small junction box (12.5v), I followed the red main line across the radiator support to a large relay (12.5v), disconnected the red line off the firewall (12.5v), I disconnected the ignition plug and the red wire has (12v).

There is also a black wire that comes off the small junction box that also runs across the rad support that has 2 small inline fuses (think 4amp) and I have checked and there is power along that line.

I followed the purple wire from the ignition to outside the firewall (0.9v) then at the starter it has 0.92v at the solenoid when turning key to start position.

I went back to the large relay (think it is for the alternator) and checked the other wires:
Yellow wire – 2.16v with ignition off, 0.04v with key turned to Assy, and 0.5v when key turn to start position. Blue wire and brown wire 0.0v no matter what position the key is in.

I followed the Blue and Yellow wires to the Alternator:
Both wires read 0.00v at the alternator connection and the orange power wire has 12.5v

I have replaced the ignition switch but still no change. I pulled out the started and brought it to get tested and it tested fine. I have no idea where else to look for a fuse or what could be wrong.
Any comments/assistance would be appreciated. Thanks

Re: 1972 C20 will not start/seems like no electic power
 

Here is a picture of the small junction block next to the battery that I mentioned. You can see the main red wire and the black wire with the inline fuses.

Re: 1972 C20 will not start/seems like no electic power
 

I'd get the ground at battery off the fender to stsrt.

Re: 1972 C20 will not start/seems like no electic power
 

Yeah I fully agree. Get a good ground

Re: 1972 C20 will not start/seems like no electic power
 

>>I followed the purple wire from the ignition to outside the firewall (0.9v)<<

Inside the firewall connector, that purple wire goes to the Neutral safety switch and from there to the Ignition/Start switch which is where it gets its 12 Volts for the starter solenoid.

My first check would be the Neutral safety switch for voltage on both terminals with key in "start".

Re: 1972 C20 will not start/seems like no electic power
 

The main battery ground wire goes to the engine, that is the little extra wire off the negative terminal. I'm use to square bodies which that wire is connected to the radiator support. That wire was there when I got the truck over a year ago and it never seemed to be a problem. But I'll try moving it.
Thanks

Re: 1972 C20 will not start/seems like no electic power
 

Thanks Richard - I'll check the Neutral Safety switch in the morning.