[Ben Munyan]

I am combining a 1992 d150 2 wheel drive(body,motor) with a 1982 3/4 ton 4x4(frame tranny) to end up with a halfway decent truck.I lost my 82's body due to cancer brought on by ohio's use of salt during the winter months.So i bought a solid and good running 92 to replace the body and fell in love with the magnum motor in the process and decided to use it.I've got the truck close, but the 1992's wiring harness has a plug for an electronic overdrive that my 82 tranny doesn't have, and it's not allowing me to turn the motor over.Any suggestions? All help greatly appreciated.

 

[Ben Munyan]

almost forgot, both tranny's are automatics.

 

[KOG]

Now you're in trouble. Try posting on the tech line at http://moparaction.com/

 

[B10alia]

Why not just swap the tx's? I can't imagine it'll be much harder than putting in a motor.

 

[KOG]

Because he's got a 2WD new one and a 4WD old one. That also can be done, but not that simple a swap.

 

[Ben Munyan]

yeah, trying to figure out how to 'trick' the computer into liking the 3 speed.worse comes to worse, may have to invest in a newer tranny.Sure would have been easier to do prior to sitting the new cab on there.To make matters worse, the 4x4 frame i'm using is of the military variety so my bed mounts need played with to fit the donor bed on there.

 

[valiant67]

Besides that, the old 3 speed won't have the provision for the Magnum's crank sensor which you need unless you're converting to carb and electronic ignition on the motor.
You could probably make the Magnum work with the three speed if you used a manual trans computer and worked out the crank sensor issue.

 

[Ben Munyan]

Doesn't the crank sensor read the gaps in the flex plate via magnet? I already notched a hole in the old tranny and the crank sensor is mounted right where it should be.

 

[dana44]

You most likely have a wiring diagram, so track the wiring and see if there is some sort of neutral lockout that needs to be grounded. If the computers from an automatic can run with a manual transmission, no reason why this plug-in is giving you problems, Have you checked for error codes? And as noted, did you notch the transmission case for the crank sensor location?

 

[Ben Munyan]

the error codes are both for the overdrive solenoid circuit.which makes sense because my tranny has no plug in for o/d being its a 3 speed.and yes, i did notch the tranny for the crank sensor and it mounted up just fine.i am studying the wiring diagram right now hoping to figure out the hold-up.

 

[dana44]

Like I said, there are a couple guys that have placed manual transmissions behind automatic computers and the overdrive wiring was not utilized and they started. Yes, an error code will show because something isn't hooked up, but but it sounds like you are not able to actually turn the engine over, right? Neutral lockout or other grounding issue preventing it from turning over that isn't showing an error code to begin with?

 

[Bearhawke]

Correct me if I wrong here; but, didn't some ca. 1992-93 Dodge trucks with the Magnum V8's also use the 727 TF tranny? I remember looking in a shop manual for a B series van saying something about that. And I believe the vans and trucks use the same basic trannys with the same model years and up/down.

 

[valiant67]

vans did run the 3 speed, but trucks did no with the V8. Some 3.9 V6 trucks still had the 3 speed.
But as stated, other than the neutral safety switch the transmission doesn't affect the vehicle starter.
One problem with using a computer designed for the automatic without that transmission behind ii is that the idle tends to hang. It may not be a problem in this application though and it doesn't happen in all vehicles.

 

[Ben Munyan]

thanks fellas.ill look into the nuetral safety switch issue today.

 

[dana44]

Remember, the neutral safety switch for a manual is a button on the clutch pedal, but for an automatic it is a switch at the end of the column or stickshift, it may not be engaging properly, or, the linkage is out of phase and not showing engagement and not allowing you to start. Wire diagram search for color/location/engagement needed to ground it out.

 

[Ben Munyan]

Ok, I grounded the center post on the wiring harness nuetral safety/backup switch to the tranny and she fired right up, then started going backwards. luckily i had put blocks on both sides of the wheels,lol.Apparentely, the 2/12 inch body lift has my linkage all screwed up, so now it's just a matter of adjusting that and she's good.Thanks fellas for the advice.

 

[TWX]

My '97 2500 Ram Van had a three-speed transmission. It was a 318 van. You might want to see if any of the 318 Magnum trucks have three speed transmissions, and get the computer from one. I do not know anything about how the 4wd works on these, so for that part I can't advise what that could do.

 

[valiant67]

As I mentioned before the Magnum V8 trucks did not get the 3 speed. It appears some Magnum V6 ones did but not the V8s.

 

[dana44]

Your computer should be fine, so figure out a way to safely have the neutral lockout switch function with her so you don't start her in gear, it can be done. Run a wire to the brake pedal and hook it up the way you would for the clutch safety switch (that has to be depressed to start), so you have to press the brake to ground the switch. Talk about an extra theft protection item!