1987 Jeep Wrangler gas gauge

Tiny
MIKE KOHLER
  • MEMBER
  • 1987 JEEP WRANGLER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 87,000 MILES
My gas gauge goes to full any time you turn over the engine, even if it is empty. I took itto a mechanic &he said it wasnt from the gas tank to the cab. He said he didnt have time to break into the dash area. Its a carberated, straight 6 cyl. If that helps.
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Tuesday, September 14th, 2010 AT 12:05 PM

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Tiny
CJ MEDEVAC
  • EXPERT
See my profile, My hobby...no pay.....Probably write you a novel (as I usually do) I am a CJ Guy, I answer---ALOT---of the CJ questions.....I know them really well, I have "messed" w/ a few Wranglers, But know little about them.

I was/am an Airborne Ranger.......Hand me a Map and I have Been There!

Fortunatly, In Amongst my Jeep Chilton 1971-1990, which was bought mainly to compare w/ other manuals I have for my CJs (some more info than others, even if written by the same company) THERE IS '87-'90 Wrangler Stuff included!.........but way more complicated!

So I have your map, not familiar w/ some of the stuff within.

Before we get into it, let me explain as best I can how the CJ system works.

Really simple, is how I will try to keep it.

1st, the thing that connects the gauge to the tank is the SENDER WIRE (along w/ a ground [chassis]).....This wire has Resistance sent thru it, via the SENDING UNIT (a little coil winding in the tank, per say)

Heres simple!.........Lets say my gauge....No register nothing, G.I.!

What's wrong???????? I can go to the sending unit wire, where It hits the Tank Sender.....Disconnect the wire and Ground it (the one going up front)......I JUST FOOLED THE GAUGE INTO THINKING THE TANK IS FULL........if my gauge works, BAD SENDER.........My Gauge No Worky, BAD GAUGE or BAD WIRING.

Then I must proceed with either situation.

How does this relate to you?........Gauge Full?......Stuck sender in tank.....Bad Gauge.....Sender Wire Grounded

Well maybe your boy, pulled the connection at the tank.......If the sending unit in the tank, was "STUCK WIDE OPEN FULL!"....Your gauge would have Dropped, no signal available for gauge to read! ONLY IF HE DID THIS PROCEDURE!

Saying it passed that test....a short, to ground on sender wire.....or........ a bad gauge.......or some wild computer stuff in your gauge cluster........ is all that is left to investigate.

(Your gauge is bad, or a short (to chassis ground) is fooling the guage into thinking the tank is full, the short is on the sender wire, and is most likely the problem now)

Now your wiring diagram, in the book, I have, (probably all books) Is the more modern.....heres a system, theres a system everywhere a system system!.....in sections

But nothing like a CJ diagram, here's a light/etc .....I can follow the wire throughout the Jeep Diagram and see what else ties in and where its final destination is......Like a road map!..................Yours is separate boxes....in random order, I am not familiar enough with it, to connect the boxes in my head (in order) to follow the wires....and figure out the location within the Jeep!

Have no fear.....So far I have figured a little of it out..........IF THIS WORKS LIKE A CJ!

I am going to help you figure out, from a connector, Rearward toward tank ..........Whether there is a problem with the Sender in the tank and/or your wire might be shorted from this connector, on back, as it makes its way to the tank..............If we unplug this connector we might kill more than the sender wire (other stuff in the connector too! maybe?)

But no problem, we will reconnect it soon as we finish this simple test...........If we unplug the tank at this location, it would be the same as doing it at the tank, except the sender wire will be included in this test!

Should this NOT! make your gauge drop.........your problem is from this connector FOWARD----SOMEWHERE FOWARD!........and the testing would have to continue FOWARD...................If it does drop, problem is toward the tank.

The connector is labeled, as to its location in this Jeep diagram

The connector appears to have 10 pins, 4 are used in various Wranglers dependent on Engine.....Yours may only use 2 of the pins (I hope the connector is the same, minus 8 unused pins) so you can identify it!

Location.........Above parking brake handle (Its in your hands to find it, disconnect it, and see if gauge drops (key on).......if it does drop, problem is to the rear.............Tank or short on the sender wire.

Come back with results....I study more in my book, till you get back, G.I.!

Read, "VOTES"....Hit "FEEDBACK"....out do the other guys!

I wrote you a book, I hunt and peck, I deserve, at minimum, a reply!

The Medic

Yes, I just proofread this.......I do sorta talk in circles......I guess I think the same way..........I kinda write it down with a lot of pauses (commas) 'cause I'm pausing in my head to to figure out whats next.......Sorry! Get a CJ......I will speak more fluently!

See I can do some stuff---this being my resume!, started with a '46 Willys Frame, Axles, tranny, transfer case and Engine.....In really sad condition........2 years of side jobs, by myself, 'cept for little hands reaching in the bellhousing to retrieve a dropped part etc!........remanufactured the entire deal, new bearings throughout, complete wiring (from scratch...no harness).........Initial investment $100....pegged out at almost 15 Grand..........But "WILLY" was worth it..........He's been my friend and my daughters, since 1991.......My daughter "Helped" me alot, during reconstruction at ages 3-5 and learned how to drive him (proficiently, 4X4 and all) at age 10, Her birthday is on the hood, 11181987 (Nov 18 1987)


http://www.2carpros.com/forum/automotive_pictures/411289_Picture_008_1.jpg



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Tuesday, September 14th, 2010 AT 8:36 PM

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