Recently decided to take on a ranger project, picked up a 91 XLT with a bad automatic trans. I plan to swap that out with M5R1 from a 92, have all the components ready to go. However, I'm also having fuel pump issues that are unrelated to the trans being toast - previous owner put in a Dana precision controls cruise control module and hacked into the harness a bit. I believe I've traced back the fuel pump to this as there is a twisted pair of wires leading from fuel pump to the Dana's cluster of wires that was 'tapped' in to the fuze box inside the cab. Since the CC doesn't work anyway I plan to remove and revert to factory OEM.

My question is, where did those fuel pump wires originally get routed to? When I follow the inertial switch outputs there are only two wires out, both leading to the main harness with ECU and out firewall to power distribution block. Am I missing some dangling connector underneath the bed? I plan to take the bed off tomorrow to investigate further but the main question still stands, where does that connector from the fuel pump lead back to on the main harness? Thanks!

 

Inertia switch to fuel pump 12v wire will be Pink/black stripe
Dark green/yellow wires(on inertia switch) come from Fuel Pump relay, 12v IN
One of these goes to computer, a monitor wire

I have connector numbers but not locations
C285 is for inertia switch should be 2 or 3 wire, the green and the pink

C401 is at the gas tank, 4 wires
Pink/black from inertia switch 12v, show a C101 connector on this wire, see below
Black, ground for fuel pump

Yellow/white to gas gauge
Orange, gas gauge sender ground


I do see C101 connector also used for VSS(speed) sensor on trans, pink/orange and grey/black wires, thats where previous owner may have spliced wires to get the speed signal for cruise control

 

Thank you for your help Ron.
The plot thickens! As it turns out, the entire mess of wires was associated with the aftermarket cruise control. The previous owner(s) spliced into the brake pedal switch and tapped into the fuse block inside the interior but I have since removed everything and put it back to stock. Lifted the bed and found the correct wire colors for fuel pump and can confirm it looks stock. The reason for the concern was my buddy's dad (pro mechanic but very busy) took a look and mentioned the ecu could have fried the wiring harness, looking around I see no evidence as such. I'm speculating that he saw the nest of CC wires and assumed they were spliced in everywhere - but it was just the two splices on the brake pedals.

I also discovered that the ECU is likley incorrect to the vehicle with these markings: E4LB-I4A459-B. Not a whole lot comes up from a cursory google search, looks like it came out of a mustang or thunderbird/fiesta/escort. The ranger struggles to start, and I can hear the fuel pump running all the time when the key clicks on. It does not prime for 2 sec and turn off like I have read it is supposed to. Truck currently only starts on starting fluid, but once started, will continue to start for the rest of the day.

Plan at this point is to continue to plow through for the manual swap. I cannot see how the ecu and the trans being bad are entirely related, shouldn't it shift based on rpm not ecu controls? I'm getting the feeling that there are many red herrings with this truck.

My main question at this point is about hooking up the new M5R1 electronically - could you explain how the wiring works for that job? I'd rather not pull an entire wire harness from the junkyard if I don't have to, given that the only yard with a 2.3L manual is about 4 hrs away. I saw the other two main posts on here regarding manual swap and they mention splicing wires for the neutral safety switch on the automatic's wire harness.... is there by chance anyone who has put that on video? (I know, millennial here asking a lot). I had assumed that the wire harnesses were the same for the most part and there was just a separate connection for a manual vs an automatic but I'm tired of assuming - I'm just going to ask. Thank you in advance!