No Power From the Switch to The Atlernator

[hdunlap]

Hello all and thanks in advance for your help. First I apologize for the long post. Situation: I am in the process of restoring/upgrading my 67 F-100 SWB. I just installed a remanufactured 460 big block which includes goodies that will help the truck get from point A to point B in a hurry. I also changed out the old wiring harness thru out the truck using a painless wiring harness specific to the truck. Installing the harness was pretty straight forward however now I have a charging problem. To try and resolve the problem I changed the alternator (had it tested before leaving advance auto), the voltage regulator, put in a new battery/new battery cables and that still did not solve the problem. I have checked and rechecked the wiring connections to make sure the wires are hooked up IAW the instructions. On a side note everything else works (lights, neutral safety switch, radio ETC) as it should. Because of the new battery the engine starts as soon as the key is turned however the voltage reading I am getting from the gauge in the truck (after market gauge) and the volt meter is between 12 and 12.8 with just the engine running and no load on the battery. When you turn on the lights or the radio the reading drops to 11-11.8 which to me mean the alternator is not charging. It is my understanding that the normal reading should be between 13.8-14 volts. A mechanic friend told me to check and see if the orange and black wire (not sure of the color but know the one he was referring too) running from the switch the alternator has power when the switch is turned on. I used a volt meter to check for current with the switch on and there was nothing, no current at all. Although I don't fully understand but he indicated the purpose of the current going to the alternator was to excite the diodes or something in the alternator to start the charging process. Since there is no current in the wire from the switch to the alternator I need suggestions/recommendations as to what I should do to get current in the wire as needed. All other suggestions as to what the problem might be are welcome. Thanks Hdunlap

[tac]

The voltage from the switch either goes to the the 'I" terminal on the regulator or the "S" terminal on the regulator. Check to she if you have switched voltage on either of them. If it is wired for a charge light it it will be on the "I" terminal and the Stator terminal on the Alternator should go directly to the "S" terminal on the regulator. If the switched voltage is on the "S" terminal of the regulator there shouldn't be any wires on the "I" terminal of the regulator or the Stator terminal of the Alternator.

[tac]

Should have read all of your post. I see you used the Painless. In this case the "I" terminal on the regulator will be switched and should have power on it when switch is on. If you do not have power to the "I" terminal when ign. switch is on it will not charge. If the instrument cluster in your truck has a an ammeter and not a charge light you must cut off and splice charge bulb and socket on the painless harness. Section 7.16.2 in the manual.

[hdunlap]

Tac
Thanks for the info and I will take a at what you suggested after work. Just so you know I am not using the indicator light or an amp meter. I am using an after market volt gauge. What is your recommendation for this setup? Thanks
Hdunlap

[tac]

I think you need to short out that socket for the charge indicator. This is how to get voltage to the "I" terminal on the regulator when the ignition switch is on. You should always have voltage on the "bat" terminal of the alternator and A terminal of the regulator. The Field should be at +12 when not running but will vary as it controls the alt output. The stator terminal will not have any voltage on it until running.