I have a 1988 Dodge dakota v6. It has had some modifying done to it such as a 318 being placed in it and a bit of wire splucing but my main issue now are the gauges. My heat, seat belt, battery power, and oil gauge work but the gas hand and speedometer do not. The speedometer is an easy fix but the gas hand is a bit more complicated. This is what I have done so far:

I have switched out the whole sending unit, no change.

Switched out the old and new sending units with old and new gas tank arms, no change.

By passed the 5 prong connector going to the unit and it had no effect.

I seen there was a alot of grease inside the connecter cleaned that out with a wire brush and got better results. the gauge stayed accurate for about ten tests. It kinda shifted to where it was 90 percent accurate, empty was a tad before E and full was a tad after F and with me being a perfection i went and messed with that and it went back to its original issue of staying in the middle then i got it to register on full but it stops responding right above the half way mark..

another huge issue is tracking the wires. The color scheme changes between 3 and 6 times.. it starts as green, light green, and yellow in the fuel sender, comes out of the 5 prong plug as black/white, purple/ blue, and something else, goes to the fire wall, goes to the multi connecter that had grease in it. from there two of the wires stay the same but the blue / pink one turns baby blue, goes into a huge wiring harness, then goes into some type of multiconnecter on the fire wall which looks good internally then from there i can no longer trace the wires. i seen 3 wires matching the original wires from the sending unit going into the back of the gauge cluster but now im not sure if that means im back on the right track since it changes colors so much..

My question is which all the metal components inside the arm looking good and with me getting it to work about ten times how much more do i need to bypass to get a direct connection from gas arm to gas gauge? Does anybody know the wiring schematics for this 1988 dodge dakota? I cant find the guide anywhere online or at the stores or library and thats a fact.

I'm thinking i can just bypass everything and get a straight line from the gauge to the arm unit but i dont know if anything specials happens to the wire before it reaches the gauge other then going thru these connecters which look pretty basic.

Has anyone has the issue, am I on the right track, what can i do since i know the arm still functions properly? I have been at this for 3 weeks now and I am going insane.

 

It does sound like maybe a wire problem or your gauge is acting up. We have a 1990 wiring diagram which is probably 99% the same as your 88. Here is the link. It is also just above this post.
https://dodgeforum.com/forum/1st-gen...e-manuals.html

 

im convinced of that too because even though i can never duplicate my results i know that ive held the fuel sending unit at an angle before or ive tugged on the wiring before and got it to work accurately. i also know that after cleaning the first connecter that i run into near the fire wall but before the one attached to the fire wall that getting that gunk out helped for awhile. i put a gauge from a 1989 on my truck and everything fit but it didnt work at all other then the check engine light and wiper fluid light i believe. different gauges for the most part, its just been so hard to find info on an '88.

 

yeah i went through that there must be a huge diff 2 years down the line because it didnt have the right info and when i finally found something relating to the gauge it was only one wire period. i have 3 wires handing the show.

 

i juiced the battery up and now its working accurately again so im not sure whats going on.. i still want to bypass as much as i can to get a more accurate idea of whats going on but its working for now.