88 2.9 ranger 4x4 xlt

[thomasrae12345]

ok new here. never posted on a forum before. i’ve been working on and rebuilding a 1988 ford ranger xlt 4x4 with the 2.9 and the fm146 5 speed transmission. i’ve come across an issue now after a lot of hours and time rebuilding almost the entire truck piece by piece of the transfer case. there’s a plug/ sensor on top with two blue tires. they have torn off from wherever they come from and my truck no matter what says it’s in “low range” on the dash. any help to let me know how to make this sensor whole again amd where the wires come from to tie into it. as this is a new problem that i’ve most likely caused. that’s for any and all input.

 

[dvdswan]

Welcome to the site.

 

[RonD]

Welcome to TRS

You must have a manual shift transfer case

What you describe is a plunger type switch on the transfer case, each of the two wires grounds a bulb, either 4H or 4L bulb
The switch's case is grounded to the transfer case which is grounded thru trans and engine
When you shift into 2WD then neither wire is grounded inside the switch, neither bulb is on
When you shift into 4H 1 wire will be grounded in the switch and that grounds the 4High bulb and it comes on
When you shift into 4L the switch ungrounds 4H wire and grounds the other wire that grounds the 4L bulb
The switches plunger rides in a Cam on the shift rod inside the transfer case

The 4L wire is grounded somewhere which is why the 4L light is on


Just as an FYI, most gauges and dash lights are operated by grounding in all vehicles, not a Ford thing
The dash gets 12volts with key on, so do all the gauges and bulbs
The "control wires" are the grounds for each gauge and bulb is the ground for that gauge or bulb
Oil, fuel, temp, are ground control
CEL, Brake, ABS, 4WD, Battery(not AMP meter) are ground controlled

The practical reason for this is less 12volt wiring running around the vehicle, so less chance of a short that blows a fuse, or melts a wire, if a ground wire shorts to ground, you just get a gauge that reads high or low, or a bulb the comes on when it shouldn't, no blown fuse or melted wire

 

[2 bronco 11s]

On your speedometer plug , were it goes in the transfer case , follow the small wrapped wire to the harness on the frame, about 4 inches from cross member. That plug ties in there. I'm pretty sure it's wired like a Bronco 11.

 

[thomasrae12345]

Welcome to TRS

You must have a manual shift transfer case

What you describe is a plunger type switch on the transfer case, each of the two wires grounds a bulb, either 4H or 4L bulb
The switch's case is grounded to the transfer case which is grounded thru trans and engine
When you shift into 2WD then neither wire is grounded inside the switch, neither bulb is on
When you shift into 4H 1 wire will be grounded in the switch and that grounds the 4High bulb and it comes on
When you shift into 4L the switch ungrounds 4H wire and grounds the other wire that grounds the 4L bulb
The switches plunger rides in a Cam on the shift rod inside the transfer case

The 4L wire is grounded somewhere which is why the 4L light is on


Just as an FYI, most gauges and dash lights are operated by grounding in all vehicles, not a Ford thing
The dash gets 12volts with key on, so do all the gauges and bulbs
The "control wires" are the grounds for each gauge and bulb is the ground for that gauge or bulb
Oil, fuel, temp, are ground control
CEL, Brake, ABS, 4WD, Battery(not AMP meter) are ground controlled

The practical reason for this is less 12volt wiring running around the vehicle, so less chance of a short that blows a fuse, or melts a wire, if a ground wire shorts to ground, you just get a gauge that reads high or low, or a bulb the comes on when it shouldn't, no blown fuse or melted wire

well i appreciate all the information and that makes sense. it was late last night so i didn’t spend a lot of time searching but in the 5-10 minutes i couldn’t find the other side of the wires. it’s on driver side frame rail where i found the broken plug. but i could not find the other end or where they originally come from. any insight to where they feed from ao i can have a better idea of exactly where to look?

 

[RonD]

Not sure on a 1988 but they should run to another 2 wire connector in the engine bay

Below is a 1992 Cluster wiring diagram which is within the 1983-1992 1st generation, but there was a change in body stye in 1989, so grain of salt
But it does show two Blue wires, Light Blue/black stripe(4L)and Light Blue(4H), so thats a good sign, lol

And it shows 2 "C" connectors between switch and cluster
C157 at the switch
Then C138 and C105 before the 2 wires get to C250 on the back of the cluster

Also a Splice S210 with a wire to ABS module

 

[RonD]

Just as a heads up if you are doing alot of wiring or other restoration to the 1988

Keep your eyes open for a 1988 Ford Ranger EVTM(electric/vacuum trouble shooting) manual
Like this one: https://www.ebay.com/itm/1988-FORD-...Diagrams-EVTM-Manual-EWD-/352285548096?_ul=IN

Seems a little pricey to me, lol

Ford sends out Shop Manual Sets for EVERY MODEL, EVERY YEAR to EVERY DEALER
One of the books in this Shop Manual Set is the EVTM, and its often sold separately
EVTM show where every wire is located and every connector's location, its what the Ford mechanics need to diagnose and trace wiring issues
It covers all engines, options and 2WD or 4x4 models
Very good to have, and its basically FREE, because when you are done using it you can resell it just like the person on Ebay is doing now

Ford renamed EVTM to "Wiring Diagrams" in 1999 or so, just FYI
So these are out there for every year Ranger, 1983 thru 2011

 

[2 bronco 11s]

well i appreciate all the information and that makes sense. it was late last night so i didn’t spend a lot of time searching but in the 5-10 minutes i couldn’t find the other side of the wires. it’s on driver side frame rail where i found the broken plug. but i could not find the other end or where they originally come from. any insight to where they feed from ao i can have a better idea of exactly where to look?

I should of said they come out of the main harness, there is no plug there. The plug goes to the switch. Here are some pictures.