How to: modify MJ sending unit for 97+ (and presumably standard H.O)

[JeepcoMJ]

Thought I would do this thread for future assistance to our members, either to make 97+ swaps easier on members, or to allow the use of a 91 to 96 potentiometer and float in an MJ tank.

 

Looking at the first picture, we have a Renix MJ sending unit on the left, High Output MJ in the middle, and 97 on the right.

 

After looking at alot of options for the swap, I've decided to stick with simple.  The tj tank absolutely didn't appeal to me, as I don't want it that close to the drive shaft.  The Dakota option was close to what I wanted, but with fabrication work that I think less than necessary.  I don't want to drop the MJ tank any lower to install a top load pump and lock ring, and I also am not interested in having the fuel tank be in the bed.

 

So, here is the game plan:

Turn the Renix fuel sender into a 97 sender.  I do have two shorted H.O. senders that are complete, but do not desire to modify or butcher them in any way due to rarity.

 

Step 1:  carefully disassemble 97 pump, leaving the potentiometer attached to it's mounting plate.  This is as simple as cutting the 4 corner tabs, which I did with a pair of end cutters.

 

Step 2:  carefully disassemble the top of the 97 sender, removing the fuel pressure regulator, wiring, connectors, as well as the fuel pump itself.

 

Step 3:  remove the Renix potentiometer, float arm, and harness.  The potentiometer is just a couple of clips, and will likely break.  You will need to cut the float arm.  I recommend doing it at the pivot point, in order to use it as a template to verify that your 97 float arm matches.

 

Step 4:  mounting. The new potentiometer and float arm.  

First off, I noted that the m7 and 88 sender had the same distance from point a (pivot) to point c (center of float) and the same range of motion was noted between the 97 and the 92 units.  That makes this a very straightforward swap, as the distance between these points will always be the same throughout its arc of travel.

This allows for us to use the original float arm pivot point as a base line for height.

Secondly, keeping the 97 potentiometer attached to it's mounting plate is a huge bonus for easy mounting.

 

Locate the hole through which the Renix float arm passed, and using a square off of the sending unit's center axis (center of vertical tube...i.e. fuel return), mark across the Renix potentiometer mounting plate.  You will need to drill a 1/2" hole to pass the pivot point of the h.o. sender.

Step 5:  mounting the 97 potentiometer.

 

Step 6:  to be continued.

[IDMJ]

Do you have any updates on this swap?