Help with issues after v8 swap

Deadeye512xr · Oct 31, 2017

So here's the sitrep. I have a 1998 ford ranger xlt reg cab 4x4 manual 3.0 (before the swap) it now has a 1997 ford explorer 5.0 with an m5odr2 transmission and a bw4406 electric shift transfer case. I'm having a few issues that I was wondering if anybody else had the same issues and how did you fix them?
- 4x4 low not working but 4x4 high works (yes I'm stopped and push the brake and clutch in) and hubs not engaging
- occasionally will get a code for speedometer (po500 i think) could this be part of my 4x4 low problem
- not sure if this is related to the vaccum hubs but p1451 which is a canister vent solenoid
- fuel gauge reads 3/4 when full and empty after 10 gallons are used up
**note** as far as what I did for the transmission harness, I pulled all the wires related to the shift solenoids and torque converter clutch and the range sensor except the two wires for neutral to make it start
Tell me what I did wrong guys any help or tips won't be forgotten

Sent from my SM-G920V using Tapatalk

RonD · Nov 1, 2017

GEM(generic electric module) controls 4WD system in 1998 Ranger

Do 4WD lights flash at any time?

I assume the Brake Lights work?

There is a Red/green wire on the brake switch that goes to GEM, it needs 12v, brakes on, to access 4low in GEM

P0500 can prevent 4low since GEM isn't sure of the speed, i.e. 0MPH to shift to 4low
In 1998 Rangers rear axle sensor connects to GEM directly(well spliced with ABS module wires), the GEM then converts the rear axle VSS pulses to 8,000PPM and sends it out to speedometer
So speedometer works and is reasonably accurate?

There is a Red/white wire on the GEM(pin 22) that needs to be Grounded to show trans is in Neutral or Clutch pedal is down all the way, also needed for 4low

So yes those are the 3 things needed to access 4low, 12volt at Pin 13, Ground at Pin 22, VSS showing no pulses, but other wise working

The PVH solenoid is operated by the GEM but there is no "sensor" that tells GEM if it is working or not so hubs locking or not wouldn't prevent shift to 4low

There are some articles here about repairing PVH or replacing it: http://www.therangerstation.com/tech_library/index-axles.shtml

PVH is part of vacuum system so if its solenoid didn't get hooked back up after engine swap then it wouldn't work and it could cause vacuum leak which might be detected by EVAP system sensors

Fuel gauge shouldn't be effected by the swap, I assume same 1998 Ranger instrument cluster
The sender in the tank was also connected to the 1998 Computer, pin 12 on computer, yellow/white wire
1997 explorer computer may or may not have had this Low Fuel Warning, so that could effect OHMs at gauge
1998 sender should have 16ohms Empty and 158ohms Full

Deadeye512xr · Nov 1, 2017

RonD said:
GEM(generic electric module) controls 4WD system in 1998 Ranger

Do 4WD lights flash at any time?

I assume the Brake Lights work?

There is a Red/green wire on the brake switch that goes to GEM, it needs 12v, brakes on, to access 4low in GEM

P0500 can prevent 4low since GEM isn't sure of the speed, i.e. 0MPH to shift to 4low
In 1998 Rangers rear axle sensor connects to GEM directly(well spliced with ABS module wires), the GEM then converts the rear axle VSS pulses to 8,000PPM and sends it out to speedometer
So speedometer works and is reasonably accurate?

There is a Red/white wire on the GEM(pin 22) that needs to be Grounded to show trans is in Neutral or Clutch pedal is down all the way, also needed for 4low

So yes those are the 3 things needed to access 4low, 12volt at Pin 13, Ground at Pin 22, VSS showing no pulses, but other wise working

The PVH solenoid is operated by the GEM but there is no "sensor" that tells GEM if it is working or not so hubs locking or not wouldn't prevent shift to 4low

There are some articles here about repairing PVH or replacing it: http://www.therangerstation.com/tech_library/index-axles.shtml

PVH is part of vacuum system so if its solenoid didn't get hooked back up after engine swap then it wouldn't work and it could cause vacuum leak which might be detected by EVAP system sensors

Fuel gauge shouldn't be effected by the swap, I assume same 1998 Ranger instrument cluster
The sender in the tank was also connected to the 1998 Computer, pin 12 on computer, yellow/white wire
1997 explorer computer may or may not have had this Low Fuel Warning, so that could effect OHMs at gauge
1998 sender should have 16ohms Empty and 158ohms Full

4x4 high lights up when selected and the transfer case shifts into 4 high. When I select 4 low nothing happens clutch and brake in. The 4wd lights flash on once when you turn the ignition on.

Speedometer works fine but about 4 mph off last I checked with gps (po500 only occasionally comes on for some reason just like the po1451 code)

Brake lights work fine as well

I did recently replace my fuel pump assembly because I had a weak pump and my fuel gauge didn't work at all before I replaced it but it did work before the swap.

Sent from my SM-G920V using Tapatalk

RonD · Nov 2, 2017

Yes, there is a Bulb Test with key on

Check fuse #9 in cab fuse box, 7.5amp that's a separate fuse that powers BOO(brake on off) for computer and GEM, so brake lights use another fuse, #13, 20amp
And brake switch would be 2 switch setup, I assumed they used just single switch

It reads like GEM is not getting signal to change to 4Low, light should flash if GEM detects a problem in the system, but not if it doesn't "know" driver wants to change transfer case.

4WD switch just uses 2 wires(+ 2 for back lights), inside the switch are 3 resistors
GEM sends switch low voltage and watches return voltage, the change in voltage tells GEM which resistor is being used, so which selection driver has made.
Cruise control uses similar setup.

I would pull the radio to get to the GEM and it wiring, that way you can test brake and clutch wires and also switch resistance as you move it

I posted 1998 GEM and 4WD wiring before in this thread: http://www.therangerstation.com/forums/showthread.php?t=162915

Fuel sender has a Yellow wire that runs to the dash, via passenger side kick panel, it is part of Fuel Pump power wire harness coming from inertia switch.
Fuel pump and sender use separate ground wires, but are often grounded at the same place in passenger side kick panel.

I assume the new Fuel pump assembly was for Ford, not a universal, senders are OHM specific for the gauge used.

If you have the old assembly test with ohm meter, 16ohm down(empty), 160ohm up(full), approximate

Help with issues after v8 swap

Deadeye512xr

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