i was out trying to diagnose some wireing issues with my truck and when i was comparing the wire diagram in my haynes manual to the wires that were on the truck, i got confused. the book shows it should have all 4 wires hooked up. my truck only has the botom 3. is this right????i just got more confused and when i tried to look into the digram more. thos things confuse the heck out of me. im tryin to find out why my battery isnt getting charged. i have done all the basics and pretty much figered out that it is in the wireng somewhere. with truck off i have 12.24 volts at the batery. with it running and while on the gas it is at 12.09. it doesnt increase with engine rpm. i have gone throught several baterys, alternators, voltage regulators and bat cables. i dont knwo where to start other than pull fuses and see if anything changes. one of my freind mentioned maybe the nuetral safety switch or the ignition switch. wich could both be the problem because i dont even know if i have a nuetrral safety swith because i can start the truck in gear and my ignition switch is rigged up to a push button start switch but youy still need to have the key in the start position to start it. all done by the prior owner. not me ...suprisingly...though it does look like something i would doo i need to invest in one of the cd rom manuals. i hear they are better than the haynes. does anyone in the northern virginia area have one fpor a 75 ford f-100????? sorry for the long post i just got into writing it. the manual has tired me out.

 

Standby...

Mill1on will be along shortly with the answer to your dilemma.

 

I am going to switch you to the wiring guru's in the Electrical forum. You can also buy a good OEM CD manual from our online store here. It has wiring and vac diagrams as well as lots of other extrta's like original sales brochures which can be fun.

 

anyone????????? this is why i usually post questions like this in year specific forums. i always seem to get more replys in the 73-79 forum. i just need some help. i will let you guys know what i find out today while i am out tinkering.
i have an extra ignition swith so i am goin to try puting that in and see if it changes anything. i am also gonna figer out what is up with my nuetral safety switch if i even have one. i installed a brand new solenoid yesterday and still no change. i also have a new engine to ground wire that i am going to install today. and i will clean up all conections that i didnt get to yesterday. i really just need to know about all the wires at the voltage regulator seems how i only have 3, well 4 but only 3 of the 4 terminals are being used. according to the digram and color codes i should have a alternator light or something like that. but i dont i have a ammeter. confuses me. i think some stuff was swapped befor i got the truck. ill keep yall posted.
i plan on purchasing the cd rom on the 15th. even if i do figer this wireing problem out. it would be nice to have about now.

 

Should be 3 wires:
orange from regulator to alternator "Field"
yellow from regulator to battery positive, most likely on the front large terminal of the starter relay
green/red stripe from regulator to ignition switch

possibly a 4th wire, white/black stripe fron regulator to alternator "Stator"
also may be another yellow wire going from the regulator to a capacitor, gets rid of noise on the radio. It would come off the same terminal as the other yellow wire that goes to the batttery positive.

Your ignition switch could be the problem. It sends 12 volts from the battery out to the regulator on the green/red stripe wire to turn the chraging system on.
Or could be the orange wire is broken, it turns on the alternator and controls how much voltage it puts out.
Or it could be the yellow wire it tells the regulator how much voltage the alternator is putting out.
Try measuring the voltage right at the alternator "BAT" terminal. If it is roughly 13.5 to 14.5 volts the charging system is working. So the problem is the wire from the ALternator "BAT" to the battery positive.
Also check for 12 volts on the green/red wire with the key on. If nothing that is the problem. Which very well could be the ignition switch or a bad green/red wire.
Keep us posted on what you find out.

ps
The neutral/safety switch has nothing to do with this problem, unless the previous owner wired it in some how

 

ill have to try testing all those wires. i replaced one wire at the ignition switch the red with blue stripe on it, it was worn through, but didnt fix my problem. the spare ignition swith was different from the one that is in my truck now so the conecter is wrong. anyways i went under the hood and pulled all the tape off of the alternator and regulator wires. replaced the white wire, didnt fix the problem but now my ammeter guage almost works. it actually moves now when u turn something on. the fuseable links seem to be good. i have current going through all of them. i am lost now. alls i am doing is killing my battery and its a matter of time beofr it is dead and i have to call it a day while i charge it. would the RFI capasitor right near the regulater have something to do with it????? or could i just be stupid and it be a bad alternater. i have replaced about 6 of them over that past 2 years and still no luck. i might try and swap out regulators and see if it does anything. thanks for the replys keep em coming. i am trying everything from all the other posts about charging systems.

 

Like sparky said, make sure you have 12 volts on the "s" terminal on the regulator. Since the ign switch has been monkeyed with, it may not be hooked up.

 

well i got it working now. my batery is charging. i checked all the wires as sparky said to and i had everything going to the regulator. just none comeing out. had the 12 volts on the wire from the ignition switch. what it ended up being was i must have had a bad voltage regulator. i had 2 old ones in the truck box, the one i took off the truck some time last year and one i got from parts truck i bought last year and have since gotten rid of. anyways i put the regulator from the parts truck on and it worked. i must have had a bad regulator the whole time. thanks for all the replys. they did help me find some bad wires even though they werent the problem.


edit: thats the best digram i have seen. too bad i didnt have that several hours ago.