A question of 4 connections: what are they?
#31
03-14-2012, 08:15 AM
Posting Legend
FWIW, the engine harness side of that green wire plug is the main difference between I6 and V8 engine harnesses. V8 uses the black wire as an extra ground for the tach, where the I6 doesn't. The black wire grounds the "V8 corrector" built into the factory tach.
That brown wire has me curious. I wonder if it has power when the parking light circuit is in use? If it is for fog lights, I bet it doesn't, but has a matching unused plug under the dash........
That brown wire has me curious. I wonder if it has power when the parking light circuit is in use? If it is for fog lights, I bet it doesn't, but has a matching unused plug under the dash........
What is the "parking light"? When I used to "park" I didn't want any lights.
#32
03-14-2012, 08:29 AM
The brown wire threw me for a loop. The rest were pretty easy, as you found out.
The round connector with the green wire, near the ignition module, should have a matching plug somewhere, though it will likely have a green and black wire (the plug has 2 ports, but only the green wire on the one you pictured). It was often not plugged together on trucks that did not recieve a factory tach, but both halves *should* be there, somewhere. I bet the other plug is hidden under the brake booster.
Should you ever upgrade to a tach cluster, that plug will need to be connected, otherwise, it can be left alone.
FWIW, the engine harness side of that green wire plug is the main difference between I6 and V8 engine harnesses. V8 uses the black wire as an extra ground for the tach, where the I6 doesn't. The black wire grounds the "V8 corrector" built into the factory tach.
That brown wire has me curious. I wonder if it has power when the parking light circuit is in use? If it is for fog lights, I bet it doesn't, but has a matching unused plug under the dash........
The capacitor/condensor at the voltage regulator (yellow wire) was only installed on trucks that left the factory with a radio. No radio = no chance of having an alternator "buzz" thru the speaker......
Not sure about the one on the coil. It may well be the same way.
The round connector with the green wire, near the ignition module, should have a matching plug somewhere, though it will likely have a green and black wire (the plug has 2 ports, but only the green wire on the one you pictured). It was often not plugged together on trucks that did not recieve a factory tach, but both halves *should* be there, somewhere. I bet the other plug is hidden under the brake booster.
Should you ever upgrade to a tach cluster, that plug will need to be connected, otherwise, it can be left alone.
FWIW, the engine harness side of that green wire plug is the main difference between I6 and V8 engine harnesses. V8 uses the black wire as an extra ground for the tach, where the I6 doesn't. The black wire grounds the "V8 corrector" built into the factory tach.
That brown wire has me curious. I wonder if it has power when the parking light circuit is in use? If it is for fog lights, I bet it doesn't, but has a matching unused plug under the dash........
The capacitor/condensor at the voltage regulator (yellow wire) was only installed on trucks that left the factory with a radio. No radio = no chance of having an alternator "buzz" thru the speaker......
Not sure about the one on the coil. It may well be the same way.
And here's a wider shot showing both the tach plug and fog light connections.
#33
03-14-2012, 10:09 AM
Somebody ping Ralph
I at first added a factory tach, just got a matching pigtail connector from the JY and ran some wires from that connector up to the dash.
I later replaced the entire harness that had all that extra wiring already wrapped in.
Fog light wiring....
- Brown wire supplies power to fog light switch in the cab.
- Other side of the switch has a light blue/black-stripe wire, which energizes the fog light relay.
- Said relay uses a yellow wire (Circuit 37) to power the lamps via tan/orange-stripe wires.
Source: 1981 FoMoCo Truck Wiring Diagrams Manual
#34
03-14-2012, 10:14 AM
#35
03-15-2012, 04:19 AM
#36
03-15-2012, 07:28 AM
We are all standing by, anxiously awaiting your report. Inquiring minds want to know!
#37
03-15-2012, 07:32 AM
Posting Legend
#38
03-15-2012, 09:10 AM
Cargo Master
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#39
03-15-2012, 11:14 AM
Post Fiend
That was my guess, which is why I was curious if it had power with the running lights on.
#41
03-15-2012, 02:36 PM
Posting Legend
This has reminded me that I was supposed to confirm that the '81 wiring diagrams show a capacitor on the six as well as the eights. And, it does. It actually shows three separate distributors, one for the 6, one for the 351M/400, and one for the 302. But, it shows only one coil and one capacitor.
So, it looks like everything came w/the cap on the ignition, as well as the alternator. Granted, this doesn't prove it, but there are no notes, nada.
So, it looks like everything came w/the cap on the ignition, as well as the alternator. Granted, this doesn't prove it, but there are no notes, nada.
#42
03-15-2012, 02:51 PM
#43
03-15-2012, 02:55 PM
Posting Legend
Don't think it is a mystery any more. Some PO or mechanic probably ditched the cap's at some point. Easy to see on the regulator as it has to come off to get the reg off since they share a screw. Don't know where the cap is for the ignition on the six, but I would think it would take some work more serious than a tuneup to make that happen.
#44
03-15-2012, 03:02 PM
Post Fiend
#45
03-15-2012, 03:17 PM
Way back during the great Radio **** Debate on another thread, we deduced that my truck had come with a monoaural (monaural?) radio, as the original mounting-grounding bracket was still in the dash. The dash speaker had been removed along with the original radio. A Sanyo cassette deck had been jammed into the dash in its place, hotwired to a plug that was inserted in the cigar lighter.
Conversely, it is my considered opinion that the POs were unaware of the location and/or purpose of the hood release. To that extent, it is indeed improbable that they would have removed the capacitors.
Conversely, it is my considered opinion that the POs were unaware of the location and/or purpose of the hood release. To that extent, it is indeed improbable that they would have removed the capacitors.