Ignition switches wirin

[THE-HOG]

I put whole new wiring harnesses in my 75 w100 with the 5.2 & it cranked then, put a new ignition switch in and now it doesn't crank. The switch has 2 thick wires and 4 small wires. My big wires are correct but I don't think my small ones are and I can't figure out a way to correct it.

 

[65 sporty]

I did some searching and found this, but you said you have 6 wires

 

[58pwrwgn]

You need to find the wire that is only hot when the key is turned to hot. This needs to be connected to the wire going to the starter relay.

 

[58pwrwgn]

Are you using the 5.2 computer. If so does that control the starter relay

 

[THE-HOG]

I did some searching and found this, but you said you have 6 wires



View attachment 24786

I already have a book for my truck but the Napa ks6691 (?) ignition switch has a brown black red yellow brown blue and a skinny black. Wiring harness has the book-match red pink, orange, skinny orange, black, blue/light blue,

 

[THE-HOG]

Are you using the 5.2 computer. If so does that control the starter relay

I do not believe so, how do I tell?

 

[58pwrwgn]

I looked up napa ks9961 for a wire diagram but get a Ford switch. I you have an ohm meter, find out which pair of wire give you continuity when the switch is turned all the way to start. Or if you have the 12v power lead hooked up, find the one that gives you 12v when turned to start. By the wire diagram , if correct, above this wire should connect to the yellow wire on the harness

 

[Casca2525]

Strange my 75 b300 has 5 wires, and the original wiring harness, I bought a new switch from car quest and it plugged straight into the stock connector

 

[volaredon]

Are you using the 5.2 computer. If so does that control the starter relay

No computer on a 75

 

[THE-HOG]

I looked up napa ks9961 for a wire diagram but get a Ford switch. I you have an ohm meter, find out which pair of wire give you continuity when the switch is turned all the way to start. Or if you have the 12v power lead hooked up, find the one that gives you 12v when turned to start. By the wire diagram , if correct, above this wire should connect to the yellow wire on the harness

There is no yellow on the harness, there is on the switch. I got two pairs with continuity. Black and blue when on, meaning those are my accessory and running ig. And on start yellow and brown go, meaning those are my start ig. And starter. When I wired the yellow to the pink for the starter, and brown to the medium size orange for start ig. And turned the key nothing happened

 

[THE-HOG]

I looked up napa ks9961 for a wire diagram but get a Ford switch. I you have an ohm meter, find out which pair of wire give you continuity when the switch is turned all the way to start. Or if you have the 12v power lead hooked up, find the one that gives you 12v when turned to start. By the wire diagram , if correct, above this wire should connect to the yellow wire on the harness

It's a universal switch, not brand specific, I did this test earlier today, see response to 58pwrwgn for outcomes

 

[THE-HOG]

As stated when responding to 58, a blue and black when pwr on, yellow and brown when pwr start, unlabeled unknown. Also, is the windshield wiper switch a required component to crank for some reason? Wiring harness is the wires going in the plug. Saw the guy saying 6 wires is weird, it's a fac harness, with 6 going in the plug, and a universal switch with 6 coming out. I think 5 is probably weirder.

 

[THE-HOG]

I did some searching and found this, but you said you have 6 wires



View attachment 24786

I have a book for my truck specifically, it shows the six wires I have, that's not the issue. In my other photos in this thread you can see the wires in the plug that match the book, and the hard to read switch wires.

 

[65 sporty]

I put whole new wiring harnesses in my 75 w100 with the 5.2 & it cranked then, put a new ignition switch in and now it doesn't crank. The switch has 2 thick wires and 4 small wires. My big wires are correct but I don't think my small ones are and I can't figure out a way to correct it.

Why did you change the ignition switch if it cranked with the original switch?

 

[volaredon]

You say whole "new" wiring harness. I hope you didn't go with "painless". They aren't.

 

[58pwrwgn]

I found this diagram. The color are not all the some.

 

[58pwrwgn]

Based on this picture . Best guess
Orange - start
Lite blue, your blue/white- accessories
Red - ignition run
Pink - ignition start
Black- batter
Orange - ???

Your switch. Best guess
Brown- start
Yellow- ignition start
Blue- ignition run
Black- accessories

What happened to the old switch that you are changing.
Has it been awhile since the truck hasn't been working.
If you think you have it wired correctly, you will next need to see if you get power at the starter relay.

 

[THE-HOG]

Why did you change the ignition switch if it cranked with the original switch?

Becuase the alternator went out and burnt all the wiring harnesses including the old ignition switch. It's quite common for the ig switch to burn on these trucks.

 

[THE-HOG]

You say whole "new" wiring harness. I hope you didn't go with "painless". They aren't.

Engine harness from can't remember rn, but it's an old stock refurbished, under dash harness from brads nos parts

 

[THE-HOG]

Based on this picture . Best guess
Orange - start
Lite blue, your blue/white- accessories
Red - ignition run
Pink - ignition start
Black- batter
Orange - ???

Your switch. Best guess
Brown- start
Yellow- ignition start
Blue- ignition run
Black- accessories

What happened to the old switch that you are changing.
Has it been awhile since the truck hasn't been working.
If you think you have it wired correctly, you will next need to see if you get power at the starter relay.

The alternator blew up all the wires 5 months ago in a short. Ram strong before that. Wires to the switch were blown out too.