Is there a 2nd computer on a 91 Dakota?

Posted by: poorboy

Is there a 2nd computer on a 91 Dakota? - 11/10/17 08:46 PM

OK, I pulled the dash out of a 91 Dakota to hijack the wiring harness. Over in the right upper kick panel is a black box about 5" square with a wire attachment of about 10 wires (I didn't count them). I know the mid 80s cars had a logic module in that kick panel, but I thought those went away with the OBD1 system. Is this box the equivalent to the logic module? My coupe has a dash wiring harness from a 90 Dakota in it and I don't remember there being such a box attached to that harness, but that was 5 years ago.

The OBD1 ECU was under the hood and the truck was a stripped down v6 5 speed with very few options. This box was pretty well hidden behind the heater/ac unit and I didn't even know it was there until I pulled the dash.

What am I seeing? Of course I don't have a picture of the box, but I suppose I can get one. Gene
Posted by: buildanother

Re: Is there a 2nd computer on a 91 Dakota? - 11/10/17 08:55 PM

I seen a box like that on one
of my 90 ramchargers. I thought it was a module for the rear wheel abs.
Posted by: poorboy

Re: Is there a 2nd computer on a 91 Dakota? - 11/10/17 09:29 PM

Well now, there may have been abs on this truck at one time. There wasn't anything there when I took it apart.
Would this be something I can remove? The "new" truck will definitely not have abs. Gene
Posted by: rhad

Re: Is there a 2nd computer on a 91 Dakota? - 11/10/17 10:36 PM

if you are going to use the complete dash from the abs truck and not have abs the light on the dash will need to be removed,check close on the frame at the rear where the rear brake line is,if the modules are different use the non abs one
Posted by: poorboy

Re: Is there a 2nd computer on a 91 Dakota? - 11/11/17 12:15 AM

To make a long story short, I'm building a hot rod (39 Dodge pickup on a Dakota chassis, 5.9 Magnum powered), and the unhacked wiring from this 91 Dakota has volunteered as my wiring harness.

I will not be using the motor part of the harness, I'm installing a 5.9 Magnum with its attached trans and I have a Hot Wire stand alone harness to make it run.

The Hot Rod project is on the Dakota chassis, so I can use the Dakota harness to power everything other then the motor (like the lights, radio, gas gauge, wipers and so forth). I won't be using the Dakota instrument cluster other then the gas gauge, but I will be using all the switches from the dash, just not in it.

I probably should buy a fsm for the 91 Dakota, I have an 87 Dakota service manual, but its too old for the wiring, so the only thing a 91 fsm would be useful for would be the wiring diagrams. I can't seem to find just a wiring diagram for the Dakota anywhere. Gene
Posted by: rhad

Re: Is there a 2nd computer on a 91 Dakota? - 11/11/17 11:42 PM

what year frame and rear axle are you using,my 92 has rear antilock and the module equalizer thing is different than a non antilock
it should look different,a quick look should tell the tale
Posted by: poorboy

Re: Is there a 2nd computer on a 91 Dakota? - 11/12/17 11:40 PM

I'm using the 91 Dakota frame. I'm using a 9 1/4 out of a 77 Dodge pickup, the Dakota original 7 1/4 is long gone because it was locked up and wouldn't roll. There was nothing on the frame at the rear indicating there was anything kind of equalizer there, and this was the 1st module I've ever seen, if that is what in deed it is. I have nothing to compare it with, and of course there isn't anything on the module telling what it is.

As I have read up on the anti lock setup, it appears the system was activated through the brake proportioning valve with an additional rear brake line, but there was nothing there either. Everything I've read says all Dakotas had this system, but other then the module under the dash, there is no signs of anything being on this truck. Guess someone went through a lot of work earlier in this trucks life. The odometer shows 198K miles, so who knows what has happened in all those miles. Gene
Posted by: DaytonaTurbo

Re: Is there a 2nd computer on a 91 Dakota? - 11/15/17 10:12 AM

Not sure on what that would be. It would not be a logic module as you are correct in the ecu in the engine bay runs the engine/trans. It could be a body control module, I know the 90's cars ran them to control stuff like lighting, cruise, wipers, gauges. Or I guess it could be abs or air bag.
Posted by: poorboy

Re: Is there a 2nd computer on a 91 Dakota? - 11/15/17 09:12 PM

I took the covering off the dash wiring harness today because I need to shrink it down to fit in the 39 cab. I need to put 10 lbs of stuff into a 5 lbs size bag (or shrink down a 60" x 24" deep laid out wire harness to a 46" x 14" area). It appears the black box must be a body control module because there is at least 1 wire from each circuit (cruise, wipers, heat & turn) going to it. Guess I'm going to find out how things will function without it, I will try to unplug it to see what works and what wont. I'm at the point I might just wire the project myself from scratch. Gene