View Full Version : 77-79 Wiring difference....With Pic now*

06-09-2009, 09:24 PM
Ok so the cab swap went and now comes wiring...All plugs seem good except this cab has a few plugs that are different...one has 7 wires running into it yet my old 77 plug is 5.....confused much all i have to say lol

m j
06-10-2009, 06:20 AM
try not to narrow it down with a description, including wire colours, or anything like that that could give a guy a hint as to what it could be.
maybe a pic would help too.

06-10-2009, 10:49 PM
will do tomorrow eve So far what i've plugged in dont work! its a XLT Ranger cab 77 to a Standard 79 Cab..so its got some differences right there...truck had Air and all that before this cab dont... But theres a couple plug ins that don't even look remotely the same...have a square 7 wire plug in that doesnt match to anything in mine!

m j
06-11-2009, 06:09 AM
there are optional harnesses
the 7 pin thing could be the camper special trailer harness that you wont need
without pics and a wire colour list we cant even begin to guess though

06-11-2009, 09:58 PM
Alrighty here it is! the green big plug is wacked to mine...It has the Gas gauge in it and i'm guessing the Wiring for my rear lights and backup lights...Good note had it running! Bad note...Not charging...


06-12-2009, 04:08 PM
the 4 prong plug on the lower left is for the rear lights, brown=marker,green=left turn/brake, and i think the yellow is right turn/brake, pop the tail lights and double check. unless you want to change the entire harnss from the old cab, I would start poking a test light in to the cab harness and figure them all out, and solder & double heat shrink them together not charging cause the gauge isnt hooked up or, is it not charging.:dontknow:

m j
06-12-2009, 04:26 PM
77 is the change year, I have a few 78 bronco harnesses and one 77 pickup harness.
checking the wiring diagrams here now.
I would say pick a harness and use it rather then trying to make one act like the other.
the harness is real simple to remove after you gut the cab :)
personally I dont like where it exits the cab over the valve cover on the passenger side, I like to move that way over to the inner fender as that is where it needs to be to go to the battery, alt, and regulator
next one I do will be hidden wiring coming with it coming out of the cab under the inner fender where it bolts to the cab

the seperate loose connectors for each run is the one thing I do not like about fords, a bulkhead connector like chevy uses is far nicer IMO
my 81 Pete uses the same style with a rats nest of connectors floating in a clump

on the 78 ford wiring diagram that green connector is called c306

680 blue wire fuel guage sender aft tank
675 green w red stripe wire fuel guage sender mid tank
977 p with white stripe wire ign power??
140 black with red stripe wire back up lamp?
283 yellow with black stripe wire left hand turn?
282 green right hand turn?

m j
06-12-2009, 04:49 PM
to charge you have to have power coming in from the ign switch on a ?green with red wire? from memory so check the wiring diagrams and your truck
iirc those wires are a bitch to chase as they go into the firewall on the ps and out on the ds :)

06-12-2009, 04:55 PM
fuck i hate wiring

m j
06-12-2009, 05:30 PM
wiring isnt that bad, if all you have to learn is one or 2 vehicles.
you have to completely rip into it with a wiring diagram and have it spread over a shop floor studying it until you figure out what the designer was doing.
when it is snaking around in a vehicle and you are unfamiliar with that particular harness you dont really have a chance to do a nice job with it.

the 77 I bought had a near virgin harness, with all the optional trailer harness and camper harness unused, some dipshit butt connectored his own trailer and camper bits into it :(

06-14-2009, 03:11 PM
ouch ya all i need to do is get charging to work and the rear light mess...everything else is a go already :D Putting the doors/Hood/and pulling the steering colum again to put a new seal on it where it meets the cab...Then i can toss my old box back on sometime this week and get it ready for a nice inspection! lmao

07-04-2009, 04:09 PM
Yes....its almost all wired and put together again! swapped my 77 lights out for the 79 Style in the end here to actually easier than i thought to do. Charging is good but i have a draw from the alternator(think diodes deaders) NOW Put hood on and grill/Box and get this bitch rolling by monday! OH and i will be shooting it flat black no matter what tomorrow haha