Distributionblock has three wires connected one runs to the alternator and splits to runalong radiator support, the other two run to the firewall and across the enginebay, I know the positive battery cable goes to the solenoid, but what powersthe block do I need to run a hot wire from the battery or a jumper wire from the hot side of solenoid to the distribution block, or does it get its power from one of the wires running to/from it? I have spent 2 days searching wire diagrams and can’t find anything. I don’t have a battery so I can’t check ifthe block is hot. 1966 ford 250 352fe

 

The block that I am looking at on the 66 wire diagram I have shows only one color wire going to it. It should be a black wire with a yellow tracer. One black yellow comes from the ignition switch this most likely is the wire you see running along your fire wall. The other black yellow comes from your alt as you have stated. Beyond that I dont know who has done what to your wiring. I just looked again and you also have a black yellow coming off of the light switch going to the parking lights that would probably be the wire you see running across your radiator support. The black yellow going to your junction block should be a larger gage wire than the ones for the park lights. Hope this helps its all I got for you.

 

If you have not messed with your wiring, you do not need to run a hot wire from the battery or solenoid.

By 66 the wiring began to get complicated by fuses and fuse blocks.

Look on the drivers side on the radiator support, you should see a small box called an electronic voltage regulator with small wires coming from it. It is the set that crosses the radiator support and goes to the alternator. One wire from the harness at the regulator should be going to a capacitor that is grounded to the support. Some trucks are missing this cap and the system works just fine as long as everything else is grounded properly.

A wire from the block you are concerned with goes to the regulator for voltage comparison/power to the A terminal of the regulator. This may be the wire you mention crossing the radiator support.

The wires that go across the engine bay at the fire wall goes to your fuse block which powers the charging system via the battery and brings power back to the battery via the fuse box terminals.

Through one of the harnesses, the regulator I terminal gets power via the idiot light and the ignition switch when the key is in the "on" position.

This is by memory but I am pretty sure it is correct as I replaced my alternator on my 66 last month and traced the wires somewhat. I hope this answers your questions.

I do not know why the engineer run such an excessive amount of wiring, just seems foolish to have the regulator on the opposite side of the engine than the alternator, maybe he had stock in the wiring harness company.

 

Here is the wiring diagram from Fordifcation I have a 1966 f 250 with wiring problems I'm sorting out as well. Dose anyone know what the V symbol is when the wire ends Like wire 21 and 137 in this diagram? http://www.fordification.info/tech/i...sterwiring.jpg

 

Those symbols usually represent connector plugs. There are several female plugs in the harness that may or may not have anything connected to them depending on the equipment in your truck. All the bullet connectors in these trucks are .180 diameter and can be a little hard to find. You will have an easier time sorting the wiring out if you buy a wiring diagram manual for a 66. The internet is great for a lot of stuff but those plan view drawings can be confusing.

 

Thanks Crop Duster. I came to that same conclusion last night after our Boy Scout meeting. Thinking the same harness could be used for multiple trucks or even cars with different stuff in them like multiple interior lights or the like. I have a newer alternator and the truck was once set up with a second battery for the camper . The wiring diagram shows a wire coming from the alternator ground to the voltage regulator and I don't know why. The voltage regulator is mounted on the frame which is grounded. Any ideas?

 

It's a ground. You could buy one of these. https://www.macsautoparts.com/ford_t...wiring-v8.html

Then it would just be plug and play. As long as you still have a Ford alternator on there.