Trouble with clutch safety switch bypass

[RonD]

PATS is Passive Anti-Theft System(no horns, no lights, so "passive")
Added to V6 Rangers in 1999 and all Rangers in mid-2001

The THEFT light on the dash is part of PATS
One of the deterrents to theft is to disable the Starter relay in engine fuse box
The key in START provides the 12v to activate the starter relay, but a relay only works if its Grounded as well
PATS provides the ground for starter relay
So if key in ignition doesn't "pass the test" then no ground, so no crank

PATS also disable fuel pump, and fuel injectors, so no way to by pass it
You could jump the starter relay and even fuel pump relay, but no way on earth to jump fuel injectors, lol

Just thinking about the 4.8v, the clutch switch can have 5v wires on it, sensor wires

 

[Sidetracker]

So, I should be seeing 4.8v on fuse 24 and at my clutch bypass? If so, then the problem is downstream? Starter relay? BTW, thank you so much for all the help and information!

 

[RonD]

No, there are 4 to 6 wires on the clutch switch
The clutch switch has 3 switches inside, 2 wires each

Only 1 switch is for starter 12volts, white/pink and pink wires

The other 2, if used, are for cruise and REV limiter, these can have 5volts present
So if you accidentally spliced in one of these wires then you would see 5v at fuse 24

 

[Sidetracker]

I'm sure I spliced pink and pink and white...

 

[RonD]

Unplug the Starter relay in the engine bay fuse box and see the the 5v goes away, if so then its coming from the PATS ground wire in the computer so not an issue, just volts no amps

 

[Sidetracker]

5v are still there with all the relays out.

 

[RonD]

There is just the 1 relay

What about the 12v with key in START?


The 5v might be coming from the radio via fuse 28, pull it out and see, still not an issue
No 12v in START is the issue at fuse 24

 

[Sidetracker]

Sorry for the late response. I pulled fuse 28 out and sure enough there is now 0 v on fuse 24 in ON and also in START (with fuse 28 in, I am measuring 5v when the key is ON and also START)

 

[Sidetracker]

I should also let you know (maybe I should have let you know sooner) the previous owner replaced the steering wheel and just cut all but one wire (black) going into the ignition. Also I don't know if this would affect the Anti theft system but, the previous owner also replaced the old engine with a 4.0 sohc engine out of a 2008 mustang...

 

[MotorBoater]

black usually ground so couldn’t you put that wire on a ground somewhere and see?

up until your last 2 messages of details I thought we were having the same problem, now I’m unsure again

 

[Sidetracker]

UPDATE: maybe I was getting false readings from some other fuse (28?) Either way, I ended up diagnosing it again and put a test light to the red/lt blue wire coming out of the ignition switch. No power on start. I then tried sending power through fuse 24 from the battery and it cranked over. So I replaced the ignition switch... one reason I didn't do this at the start, is the advertisement on ebay for the truck said that he had replaced it. He also said he replaced the starter so either he lied or there is something making these go bad? Long story short, it works now. Thanks for all the info! Is there some problem that might cause ignition switches to go bad?