i have a 77 f100 302 engine i just replaced the whole wiring harness for the truck new switches battery solenoid almost everything new. but the problem is sometimes when i got to start the truck it cranks right up the other times it wont do anything i have checked all grounds for engine to frame , engine to chasis, dash to firewall solenoid to fender wall and pretty mush every other ground but it still does this with the motor craft ignition switch and the one painless sent me with the wiring harness


CHARING PROBLEM

i have all wires hooked up on the altenator but it only puts out a little under 12 volts unless i wire another hot wire in to the power wire for the dash cluster then it shoots up to 14.5 when no hot wire is hooked to the dash power wire the ammeter reads all the way to the C but will only be putting out 11.6 volts when i splice the hot wire in to the dash power wire the ammeter comes down to the first mark to the right of dead center please help if u can

 

These older trucks have an inline fuse between the alternator and the battery to protect the truck circuits against an alternator defect such as a long power spike, a dead short or other malfunctions that can happen with an alternator. So if you are still using the old alternator to battery wire you might check your voltage at the battery with the engine running and then at the alternator battery terminal to see if you get the same reading. If nothing else then start checking voltage away from the alternator until you find your problem, that's all I got.
"bowties in the rearview mirror"

 

ok i feel like a complete idiot i had taken 2 relays off the column that i didt know wat they was there for and since i just rewired the whole truck with a painless wiring harness and everything was workin properly i knew i didnt need them well in the process of removing them i didnt notice i had removed the screws for the neutral safety switch . so there is the answer to my starting problem lol

as for the charging i was only getting 11.7 volts at first till i took the radio power wire ( switched) and hooked it to the green/red wire on the cluster
the ammeter jumped up passed the C then slowly move to the 3/4 line and now getting proper voltage to battery and same from altenator

 

... ... Huh?

 

wats confusing you ?

the previous owner had 2 universal relays at the bottom of the column that i didnt know wat the went to so i got rid of them and when i removed them i didnt realize i had removed the screw for the neutral safety switch so when i went to crank it the switch got knocked off and thats why it wouldnt crank

as for the charging problem the cluster was not putting out the right amount of amps to tell the altenator exciter to kick in so i ran a wire from the radio power ( wire that has power only when switch is on) to the power wire on the cluster which evened everything out and now when idling the ammeter will shoot to the far side of the C then slowly come down to between the half way and 3/4 marks

hope this makes it simpler for you any questions please ask

 

My confusion is that I cannot understand anything you are saying because you don't use punctuation. As such, it's not clear to me if you're asking for help or if there is still a problem. Not trying to be rude.

 

problems solved thanks