Im having problems with the charging system in my 67 F-100 with 352. A little quick history, the truck ran fine, it sat for 2 weeks and the battery went dead. The battery wouldnt charge so I had the alternator checked and it was bad. I replaced the alternator and regulator. The new alternator is good, I had it checked. Hooked everything up and it wont charge. I unplugged the regulator and it still didnt charge. I did a little more trouble shooting, here is what I have done/checked, Replaced charging harness with a known good harness, checked continuity of battery and field wires of that harness, tried three different voltage regulators, checked and cleaned all grounds, checked voltage at the alternator with engine on and off, same as battery about 12.5 volts, and checked for shorts-none. I pulled the positive cable off the battery and the engine dies. I did a full field test and the alternator did start charging up past 15 volts. I checked some other stuff that I cant remember. Ok so as far as ground wires go I have battery to block, back of engine to firewall, and two from alternator. I dont have one from body to frame, is this a possibility? Is there another wire that is needed for charging that I should check? Isnt there an exciter wire coming from the ignition switch? Ive studied the wiring diagram I have but I couldnt tell. There has to be something Im overlooking. This is driving me nuts.

 

How about the Pos wire from thr reg to the harness, id it rotted out?

 

I dont think so, I checked the battery and field wires for continuity and anyway the alternator doesnt charge even with the regulator unplugged

 

It wont, if it can not detect a need for charging, it wont charge. that why you need to chech the wire going into the harness for the reg seneing and feed wires

 

On my truck (71) with the amp gauge, if the gauge was bad or "open" then the battery will not charge. With the cluster unplugged it would not charge. Hope that helped.

j

 

It wouldnt charge plugged and unplugged or would charge when unplugged

 

Sorry I understand what you meant now. Im going to test the gauge tomorrow

 

I had this problem on my 69 250, I had re-wired the harness from the 3 locations, it still was 'off'. It turned out I had switched the wires on the back of the alternator (not that you did), the socket assembly into the reg was bad as well as the reg. after those were fixed it worked fine.

 

i feel your pain i am having similar problems with my 88 f250 am about ready to buy a single wire alt. it is just as it says. 1 wire from the batt to alt. none others needed just tape them up. done this on farm rigs and tractors. just torques me i spent 100 and some bucks on a new alt, my problem is hidden in the wireing.