Then RW may be partly right - it just didn't come with the cap's? Even tho it did come with a radio. Ok, could be. As I said early, just having the part in the wiring diagrams doesn't mean all of them had it.

 

I'm sure it came with caps if it had a radio, I believe Ford had been doing that for decades.

 

I'm waiting for a call back from Partspring, Gary. Tried to order that capacitor ($4.52), and it came up $25 shipping.

 

Hey, you can ship it to Australia for that much! Maybe your local Ford dealer or the parts store?

 

Yeah, it's ridiculous. I can be bought, but I can't be had.

 

Sorry it took so long, work arrived before daylight.
I went and looked, and sure enough, that connector is wired into the relay for the trailer "exterior" lights. According to my wiring diagram, it may also be used for the relay for the cab-top clearance lights, if so equipped.

 

Well done! Thanks very much -- Reps for you!

 

Be careful, that diagram is for trucks with idiot lights.

The trucks with gauges (ammeter and Oil pressure) are wired different.

The Capacitor on the voltage regulator is not installed if the truck never came with a factory radio. However when these go bad, it can cause a direct ground short in that wire. Someone might have removed it to eliminate a problem. Still inconclusive.

====================================

Connector #2: Both the trailer and Fog light relay plug in here.
depending on the option you get.

On the fog lamp harness extention, there are two brown wire plugs, one male and the other female. One plugs into the main harness, and the other is left open to plug the trailer lights harness into it if so equipped, or it remains open like on your truck.

 

Part number for the Capacitor: E0TZ-18832-A / F6UZ-18832-AA

That's the way they are wired though. Capacitor on Voltage Regulator 300-I6. Capacitor on the Ignition coil. 302-V8


Correct this is for the optional cab lights.

As was stated, for the Optional Trailer Lights and Optional fog lamps respective harnesses plug in there.

These trucks were wired for every option available. This made it easier to install at the dealer if so chosen. If you find an empty plug, more than likely it's for a option your truck did not come with.


Tachometer wiring...

On trucks with idiot lights, the tach plug remains open as there is no plug for it in the main harness, or it plugs direct to the computer (if equipped).

On trucks with gauges the plug is connected to the main harness, and/or computer. Even if there is no tach in the dash.

300-6 engines only have the Green wire.
V8's have both Green and black because the tach has to be grounded "twice" on the "8" terminal of the tach to read correctly for a V8.

 

Mucho good information, thanks to all who pitched in for the cause. I'm sure a lot of folks have benefited from the answers posted here.

I called Green Sales a couple of days ago and they didn't have the F6UZ-, which apparently can fetch a hefty price.

I never heard back from Partspring. No further comment.

So I called Green again today, and gave 'em the number that Gary found on the yellow (voltage regulator) capacitor: E1AF18832AA. The friendly folks at Green cross-referenced it for me, and sure enough, they had one. Five bucks.

Festus definitely had a factory radio at some point, and I'll see in a few days if this capacitor improves the reception on the '84 Ford radio I installed. It has that same ground-to-frame arrangement, and I've got a wee bit of static, so we'll see if this helps.

 

That cap will help with alternator static, but not ignition static. You really need both caps. And, btw, your hood does have a ground strap on it - right?

 

No, it doesn't. Good grief - talk about not seeing the obvious. I just took a close look at it, there's one suspect hole in the hood that looks like it was used in the past...

19A095? Any idea what the prefix is?

 

The hood is part of the shielding for the radio antenna. Remember the '69 1/2 Road Runner 6-Packs - the ones with the lift-off fiberglass hoods? A buddy of mine had one and the radio reception was awful - all you could hear was ignition. Yup, common problem for them as that hood did no shielding. And, btw, it did have resistor plug wires.

Sorry, missed the question. But, I don't understand the question. What part are we talking about? The ground?

 

A bonding strap is a bonding strap, right? Found several online - for instance, an 11-inch '73 strap would work fine, wouldn't it?

 

Yeah a junkyard should have dozens if not Dozens of Dozens.


Not only that, but it's part of the radio ground plane.

The radio antenna has to be a certain height for proper radio reception, to pick up the frequency waves. FM radio is in the 3 meter bandwidth and is broadcasted vertically as well as horizontally.

Unfortunately to have a antenna that will catch the whole wave would have to be approximately 11.11 feet long (Different for each channel) for FM reception. There are tricks to make the antenna shorter and the Ground Plane is one of these.

The hood of the truck, the roof, etc... become part of the antenna.

This article will explain it better than I could.

Ground plane - Wikipedia, the free encyclopedia

Using a Fiberglass hood reduced the effective "length" and reception of his antenna by two-thirds, or 75%.