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Does this really need to remain plugged in? I was told the trans will go into limp mode or something if it's disconnected. True?

Yup its true, I removed mine after bypassing the abs pump and sure enough the thing shifted extremely hard.

That's why I was asking you about it last night.

The VSS feed from the rear end goes to the ABS controller first then to the cluster where it's interpreted by the PSOM for the ECM. You'll need to find the schematics for your truck and jumper the VSS wires for your speedo and trans to work correctly. If you don't have an operating VSS is will spell certain doom for your transmission!

i take all of that crap out. i cut the abs harness out and connect the vss wires together and your good to go.

mkiefer wrote:i take all of that crap out. i cut the abs harness out and connect the vss wires together and your good to go.

OK. Now that sounds more like it Mark. Less wiring! Is there anywhere you could point me to help decipher what's what?

I'm a bit confused on this stuff myself. I'm looking at a 95 evtm, and it shows that the rear axle sensor has two outputs (high [R/PK circuit #523/4WABS module pin# 22] & low [LG/BK circuit #519/4wabs module pin #21]) connected to the 4wabs control module!

From the 4wabs module to the PSOM, there is a (O/LB) wire (circuit #491/4WABS module pin #39), called the "4wabs input" at the PSOM connector. I assume the "4wabs input" pin is what I want to hook a rear axle sensor wire directly to (bypassing the 4WABS module). Can anyone confirm this?

Which of the two rear axle sensor wires would I want to splice to the "4wabs input" wire located at pin#4 on the PSOM connector?

Lastly, the (GY/BK) wire (circuit #679/psom pin #7) appears to go to a splice and then to both the PCM and the "speed control/servo amplifier assembly" If I do not intend to use use the "speed control/servo amplifier assembly", can I simply disconnect it and the trans will still operate correctly (granted, no cruise control)??

I remember my VSS only having two wires. So one is a 5v reference or ground.

Only two wires for sure, but neither appear to be a ground... If one of the two was a 5v reference, the other wire should show no voltage/no pulses while the truck is parked with the engine on, correct? And that should be the wire I'm lookin' to connect straight to the PSOM pin#4?

mkiefer wrote:i take all of that crap out. i cut the abs harness out and connect the vss wires together and your good to go.

mkiefer, can you be more specific as to which wires you connect together?? I'm just about to get around to removing my 4wabs box... Thanks.

We'll I don't really wanna cut the wiring out so I'm trying to get as much out as reasonable. I have a bit of work ahead of me to remove it all cleanly. Here's my report thus far.

2 O/Y wires coming from 2 different pins on the Hydraulic Control Unit connector and another O/Y wire from the 4WABS Control Module connector meet at splice 150. That's as far as I've gotten on that part, haven't decided whether to chase it to Splice 119 and to the 2 relays&diode in the trailer relay box or simply cut right past the 2150 and cap off the remaining single O/Y wire and leave it in the engine bay. This is the only thing keeping me from getting the Hydraulic Control Unit connector out.

Right=passenger ABS sensor / Left=driver ABS sensor, just going by ford EVTM left&right.... I disconnected the Y/B and Y/R wires from the right(pass. side) sensor connector up to Connector 107 (C107F). For now I'm leaving the male side wires hooked up to C107M (3rd picture below) because quite a bit of loom unwrapping is required to remove the rest of those two wires all the way up the 4WABS Control Module connector. The left(driver side.) sensor connector & 2 wires (T/O & T/BK) come out up to the 4WABS Control Module connector with very little unwrapping of the loom. I removed the two wires [P & O/R] that run from 4WABS Control Module connector to the Pump Motor connector, but have to chase down the other two [BK(-) & T/R] through more loom and at least up to Connector 122 (once I figure out where it is...)

Thanks for posting your progress monkei! This should be helpful when I sac-up and tackle mine.

No prob, added some more EVTM pages/connector pinouts.

yo,
Here is the ABS Sensor (also called Rear Axle Sesnor, VSS or Differential Speed Sensor (DSS)) Speed Input Signal to PSOM and PCM/CC/ and so on BY-PASS at 4WABS Module Connector in 93-96 Bronco;



jumper 14 (CKT 530, LG/Y) to 21 (CKT 519 (LG/BK)

& 39 (CKT 491 (O/LB) to 22 (CKT 523, R/PK)

Pic Source: by Turbo Ghost at photobucket.com
MIESK5 NOTE; I did this on our 96; The 4WABS Controller was toasted; 2 yard Controller's were also bad; NO RETURNS!

You can split harness covering and pull it back at da conn.
Cut each wire about 3 inches from da conn & splice em or solder together; this way, the sys can be restored ezily, if needed.
A pal used jumpers w/correct size pins to jumper the conn and secured it all w/zip ties and harness tape.

Thanks! That makes sense.

Any idea where I might find this

harness tape

? I was worrying about whether electrical tape was gonna cut it for rewrapping the engine bay looms...

Harness tape is a pain in the ass. Just buy the best 3M electrical tape you can find. The adhesive won't turn into a sticky mess like the cheap stuff does.

Thanks, SteveG, for the tape advice.

Making slow progress, I found Splice 119 (S119) in between the Trailer Relay Box and the Engine Compartment Fuse Box.

My question is, has anyone removed wires from the engine compartment fuse box underside? I can't tell by looking at it how to remove the circuit 532 / O/Y wire from the bottom of 4WABS Relay #2 without breaking whatever it is that retains it. The end is a female spade terminal that hooks up to one of the blades of 4WABS Relay #2.

Anybody familiar with the correct procedure? It's usually pretty visually obvious on connectors what has to be done to remove wires, not so much the case at the fuse block....
EDIT: Figured it out, see later posts...

Well, I made an uninformed attempt at terminal removal and busted one of the plastic terminal retainer housings, fortunately its at a location for a 4WABS relay I'm removing.

In order to correctly remove terminals/wires from underneath the row of relays, there is a red plastic piece that locks in place all of the little plastic tabs that retain the individual female terminals that must be removed. The black plastic tabs lock into square windows on the terminals (see pic) which cannot be deflected enough for wire/terminal removal with the red piece in place.
Terminal:

The red plastic piece is removed by the following procedure:
Open the hinge top of the relax box, remove the row of relays. Underneath them is the red piece, which is only retained by tabs at top/bottom of the length of the red piece, pull/carefully pry upward to remove. Terminal removal becomes obvious, painless, and breakage free once the red piece is out.

Pics shortly.

Sorry - I somehow missed that post above or I would have told you what you figured out the hard way. After ripping apart MANY Ford vehicles over the years I've learned a bunch of these tricks the hard way as well. A small flathead screwdriver or an awl works well for releasing the clips pictured above.

I am going through the same thing w/ my 94 Bronco. Let me make sure I got this right before i cut everything out. I gonna connect the blue to blue and the red to red then all the stuff highlighted in green goes in my trash can. Right? My abs light will come on but everything else check engine light, tranny, ect. will not no the difference?

I am going through the same thing w/ my 94 Bronco. Let me make sure I got this right before i cut everything out. I gonna connect the blue to blue and the red to red then all the stuff highlighted in green goes in my trash can. Right? My abs light will come on but everything else check engine light, tranny, ect. will not no the difference?

Miesk says those are the wires to jumper. I plan on removing everything else, taking care not to disturb important things like the BOO switch circuit past Splice 121.

Sorry - I somehow missed that post above or I would have told you what you figured out the hard way.

Ah well, once I snap some pics it'll be out there for the whole Bronco community to see.