I guess I should of mentioned I know I have a short somewhere too I’ve been disconnecting the battery so I don’t drain it.

 

You get 11.5V at the crank fuse when you turn the ignition to the start position and the starter does not turn, correct?

Assuming I have that right then its not your ignition switch but we are narrowing it down. The remaining circuit is crank fuse>park/neutral switch on trans>starter relay>starter. Lets check the relay next. The next time it wont crank when you turn the key to start, swap the starter relay with a known good unit and try again.

George

 

You are correct about and I just tried swapping the relay with a known good and it still won’t start.

 

Cranks and wont start or wont crank? If wont crank then:

Make sure that your Ign A 40 amp fuse is good and if so measure the voltage on the purple wire at the starter when ththe ign switch is in the start position and it wont crank.

Attached is you circuit so that you can follow along:


George

 

It won’t crank I’m hoping to get some time to mess with it this weekend again sorry for all the delays just really busy this time of the year

 

When it idles it’s around 40 volts when it cranks it’s over 100 volts and after it dies it stays around 5.5-6.4 even when you turn the key

 

I’m probably mistaken about the 100 volts I just realized my decimal is jumping around but after it dies it’s 5.5 - 6.4 with the key in run or trying to start it

 

So it starts sometimes and then dies?

Other times it wont even crank?

You cant have 40 or 100 volts anywhere in the truck.

Where are the two meter leads placed when you get 5.5-6.4 volts? Is that on DC volts?


George

 

I had one lead on the stud on the starter relay that the purple wire was on then the other on the negative post of the battery

 

You have a voltage problem so we need to find out where the issue is.

1. Make sure that your battery is fully charged to 12.6V (on a charger overnight and then knock off the surface charge with 30 seconds of headlights, then everything off and measure) and your battery connections are clean and tight. Then turn on the ignition and headlights and measure the battery voltage again. If it drops below 12v then have your battery load tested. If it stays above 12v then
2. Measure the battery voltage after the truck starts, IOW the charging voltage. If it wont start then:
3. What is the battery voltage when you try to crank the starter?

George