voltage confirm

[cantool]

I hope everyone has had a nice Thanksgiving!
This concerns a '72 p/u w/ auto trans. When the ignition switch is turned to 'ON', the pink resistor wire and the brown wire going to the IGN terminal on the starter relay are energized with 12 volts and the red/blue on the starter terminal of the relay is not. When the Ign switch is turned to 'start', the pink resistor wire and brown wire to the Ign term. still have 12 volts and the red/blu wire at the starter term. is now energized w/12 volts and drops out when the key is released [red/blu is dependant on the neutral safety switch being engaged]. The pink resistor and brown ign terminal wire always supply 12 volts in the 'on' and 'start' positions. Am I correct in this? Is there ever anytime that the brown ign terminal wire would not have voltage in the 'on' or 'start' key position?
If I have been correct in all that I have stated (except for the last question), what will cause the truck to crank and run with the brown ign terminal wire disconnected?

[Thunderfoot]

The brown wire that is on the starter solenoid is for starting only. This wire gets a full 12V when the starter solenoid is activated to boost the coil spark to help for cold starts. This only happens while you are cranking the starter (as it gets its voltage from the solenoid) then drops back to the voltage that the pink resistive wire normally has after you let off the starter.
If you disconnect it from the solenoid, the motor will still start and run just fine.

Hope this answers your question...

[fordman]

shanye are you sure about removing the brown wire from the relay on the fender? i removed it once and forgot to put it back and the key would not start the engine until i rehooked the brown wire back to the relay. maybe im wrong on the color of that wire. maybe im thinking of the small red wire on the relay.

[Thunderfoot]

shanye are you sure about removing the brown wire from the relay on the fender? i removed it once and forgot to put it back and the key would not start the engine until i rehooked the brown wire back to the relay. maybe im wrong on the color of that wire. maybe im thinking of the small red wire on the relay.

Yep, the small Red-Blue one is the one that activates the solenoid for the starter to turn over + intern will send the 12V on the brown wire for extra start voltage to the coil, the brown is only for cold start.
The starter solenoid is actually two switches in one... One for the starter and the other for the 12V to the coil...

When you did that, did the starter work.... or did the starter turn it over and motor wouldn't start?

[fordman]

no nothing happened until i rehooked the wire . i must have been thinking about the red wire. sorry keep up the good work.

[Thunderfoot]

no nothing happened until i rehooked the wire . i must have been thinking about the red wire. sorry keep up the good work.

Yep that would have been the Red-Blue stripe one no problem

[cantool]

Yes, thank you for answering. Now if you can come up with a scenario as to what keeps burning up my points condensor when all things are new, electrically, under the hood?

[fordman]

runnig the radio in the acc postion will burn the points. but thats probably not your problem.

[Thunderfoot]

Radio in the ACC position is ok but in the RUN position without the engine running is bad... (Or the key in the Run position without the engine running)
The only other things would be to much point gap, or even just a tad to little could do it (especially if the shaft is getting some play it causes the point gap to close as the RPMs go up)...
If you have a volt meter check how much voltage is on the Positive wire on the coil with the key on should be 6-9 Volts...
Other then that not sure...
I haven't messed with points much in years as I convert my stuff over to the newer Dura-Spark distributor with an MSD box to control it...

[layedout72]

if you shut the truck off, and the radio shuts off, your not getting the radio constant power.

[rjewkes]

You don't want constant radio power except for the memmory.

the only reason the newer cars play for ten minutes or ujntil you open the door is they have a fader system on the power for the accessories.