Engine Wire Harness locations - please help

[Island Medic]

Can someone look in the assembly manual and explain where a stock wiring harness goes. I am trying to get back to as close to stock locations as possible. Here is what i know

- choke, coil, starter wires go along the fire wall in that plastic sleeve.
- front lights come from bulkhead inside the driver fender to the rad support, then across the rad support.
- battery cable ground to the frame
-battery cable positive to the starter down along the frame to the starter
- small black plastic junction block on passenger side fender, fusible link from battery to the junction block.

trying to finger out where the alternator wires run. from what I see they go down to the frame rail but not sure where they go from there. Any diagrams or pictures would be really helpful.

thanks

Brad

[firedemon]

I don't have a pic but on mine they go down to frame then toward the drive side headlight the voltage regulator mounted next to the headlight and the wires tie into the regulator and the main splice right in the corner where the headlight wires break out of the harness

[FirstOwner69]

Below are pictures showing how the under hood wiring on my '69 3/4 ton with A/C was wrapped, routed and secured from the factory. This will require 2 posts.

Regarding the battery cables...
The negative cable is grounded to the engine, not the frame. Mine is grounded to the right front exhaust manifold bolt/stud. The positive cable goes to the starter but not via the frame. It is secured to the engine using clips attached to the right side oil pan bolts as shown in the first picture.

Picture 2 shows the routing at the firewall toward the left front. The 12 gauge red wire is the hot wire for the optional camper wiring so you can ignore it if your truck does not have this option. Also, note where the distributor, temperature gauge and brake warning light wires exit the plastic wiring gutter.

Picture 3 shows the wire and washer hose route to the left headlight area. Note that it does not run along the frame. It passes over the top of the inner fender and is secured to the back side of the outer fender using 2 nylon barbs inserted toward the engine.

Picture 4 shows the routing of the wires behind the left headlight. This is where the harness splits to the left headlight, horns, voltage regulator and alternator.

Picture 5 shows the wire to the alternator and how it's attached to the inner fender.

[FirstOwner69]

Continued...

Picture 1 shows the wiring at the back of the alternator.

Picture 2 shows the routing through the plastic wire gutter across the top of the core support. The gutter is barely visible between the red wire and core support.

Picture 3 shows the junction block and attachment of the fusible link from the positive cable.

Picture 4 shows the passenger side of the firewall wire gutter. The fabric loom contains the wires to the A/C compressor and blower motor. Where the wires separate is not visible.

Picture 5 shows the routing of the A/C wires in the fabric loom strapped to the heater hose.

[Island Medic]

thank you very much this is exactly what I needed.

Brad

[FirstOwner69]

You're welcome! If you need any other shots I may have on file, just ask.

Jim