mullishacrew

howdy, well i have a 618 transmission i transplanted into my 93 w250 and im having troubles finding an old wiring connector off of a 94 truck that i can plug it in and actully have 4th gear with lockup, soooo i was wondering if anyone has ever made there own plug and know what each prong in the transmission overdrive solanoid plug in is for?, so i could make my own plug in and get this truck highway drivable.

unixcowboy

The plug connections are easy :

Center pin - hot
Front pin - OD
Rear pin - Lockup

Where to get a pigtail :
http://www.transmissioncenter.net/dodge.htm
near the bottom of the page is a write up on adding OD and Lockup to a vehicle.

mullishacrew

would you be able to tell me where the wires could be hooked up to in the truck for power and the lock up and od? im not to good in the wiring section but im learning.

unixcowboy

Hot wire should go to the fuse box - something that is on when the key is on.

The other 2 should each go to a switch, the other end of the switch should be grounded.
When you ground either wire by flipping the switch, that function is on.
Be sure to label the switches so you know which id OD and which is lock up.
By the way - you CAN NOT leave the lock up on when you stop the truck, it will kill the engine.
You could also put a Hobbs switch in a transmission test port and wire the lockup from the pigtail to the Hobbs then the other side of the Hobbs to the switch in the cab. That way the Hobbs unlocks the TQ when the truck slow down even if you forget to throw the switch.

kell

Quick question, unix
that site says you need a few GM parts, among them a vacuum switch

"This is a normally open vacuum switch that takes 7 inches or more of vacuum to shift into overdrive and lock-up the torque converter and 3 inches or less of vacuum to down shift and unlock the torque converter"

That kind of leaves it unclear to me. Are we supposed to hunt for a vacuum switch with those specs? Where do I install it?
I have the '94 Dodge with the 5.9L Cummins and the 37RH transmission.
Can't get it into overdrive and I need to drive the truck 75 miles tomorrow morning.

JD730

kell,
The site conversion is geared towards a gas A518, so vacuum is one method of control on a gas engine.

No need for a vacuum switch on our trucks, its useless.
Your 94 has a 47RH.

unixcowboy

If you need to drive it and want the OD working - just run the wires to a switch like I described with one terminal on the switch connected to ground and the other end connected to the OD lead...
Flip the switch and you've got OD.
IF you leave it flipped 'on' then slow down, OD will stay on until the trans shifts into 2nd. Also, when accelerating the OD will engage immediately after the shift into 3rd.

kell

Where is this electrical plug on the transmission? I can't find it.

mullishacrew

it's on the drivers side, if it's a 618, i swapped mine from a 518 to a 618 from a 94 dodge truck .