86 ranger 2.9 wiring question

[Hrphilipson]

Ok so im doing a carb v8 swap, and removed the engine harness with the engine. Both went together when i sold the engine.
I have the battery hooked up, positive to solenoid, negative grounded to frame and body, and the factory black/orange main power wire attached to battery side of solenoid as well.
My problem now is with key on i have no power anywhere on the truck. What is the missing link that im missing and probably went with the engine harness, and how do i get power back to everything in the truck?

 

[RonD]

Part of engine bay wiring but not part of engine harness

In a 1986, the Starter relay's larger post with the Battery Positive cable on it, is the 12volt power Distribution Point for the whole vehicle

Alternator connects on that post as did the 12volt power wire to ignition switch in the cab
Also the engine fuse box was connected to that post

These connections used Fusible Links, 6"-8" wire with "eye" loop at one end, that goes on that larger post with the Battery Cable
Other end of the Fusible link is connected to a wire to power something
In this case a Yellow wire that runs to ignition switch

Fusible link can look like this: https://m.media-amazon.com/images/I/41udf8zw3dL._AC_UF1000,1000_QL80_.jpg

Or this: https://shop.advanceautoparts.com/w...62A/large/5015391_dcd_85627_alt2_pri_larg.jpg

Fusible link "acts like" a slow blow fuse, and must be used or if there is a short you will burn out engine bay, a bad thing, lol

In 1986 the alternator wire shows up as Black/orange stripe, yes that goes on the Power Distribution post, but power comes FROM the alternator when engine is running, that wire is not connected to anything else, just alternator B+

You are missing at least the Yellow wire/fusible link on that post
Yellow wire comes out of the firewall at the big connector, under brake master
And look for "eye" ends of fusible links

 

[Hrphilipson]

So the solid yellow wire that comes out of the firewall ties into the black and orange stripe wires at this junction, which is what comes from the B+ side of solenoid.
Along side it is a yellow wire with white stripe. That i dont see where it goes to immediately

 

[RonD]

You most likely have a AMP gauge on the dash, and that's the Shunt connection, the yellow/white wire also goes to alternator

Headlight switch also uses a black/orange wire with fusible link
Seems like Ford got a good buy on black/orange wire, lol

Plain yellow wire will be the one to ignition switch

 

[Hrphilipson]

Ill look into this all. Im able to get the 2.9 harness back, so i can dig through it and use whats necessary

 

[Hrphilipson]

Should the red/lt gr wire in the, i believe, 8 pin connector be connected to B+ (through eca relay or not)?

 

[RonD]

Red/lt. Green wire comes from ignition switch and goes to the EEC(ECA) Relay's coil, it activates the relay with Key on
No connection to B+(alternator)

But there is another red/lt. green wire that may be on the starter relay's Battery post that runs to pin 5 on the Computer, memory full time 12volts

I have no idea of what connectors are what in a 1986

 

[Hrphilipson]

Ok. Clears that up, thanks

 

[Hrphilipson]

So the 2 yellow wires that come off the ECA relay.....where do they go and do they supply power to the body circuits possibly?
In the attached diagram, i cant tell how they end up in the power distribution box and dont know what/where the solid state deal is?

 

[RonD]

No, those 2 yellow wires in the diagram come FROM fuse 8, 30amp, in engine bay fuse box, they supply 12volt power full time to EEC relay and computer memory(not computer power)
When EEC relay is activated then that 12v power goes OUT on the Red wire(s) to power engine systems and computer

There are other yellow wires, one goes to ignition switch in the cab, its hooked to Starter Relays Battery positive post via fusible link, it power the cab electrics with key on

 

[Hrphilipson]

Thats what im trying to acheive after removing the engine/ecu harness to go carburated v8......getting power back to cab electronics.
I have the main black/orange wire from starter relay B+ that wraps around above the radiator and ties into a few other black/orange AND a yellow wire via a sort of junction. That yellow goes into the firewall.
So im sorting through the engine/ecu harness trying to find the missing connection