Interesting Gas guage issue.

[yukon]

Posted this on YT a while ago and got flamed so I'll try here with a little more info. And probably X-post to YT too.
(this will be a long story)

Car is a 99 4runner Limited, with the factory trailer light setup

My gas gauge has worked just dandy since i bought my truck. Measured good enough for me. anyways the other day I was towing a trailer for the first time since I'd bought the truck. And accelerating down the road, all the sudden my gauge drops to below empty and the light goes on. Of course i pull over expecting a huge puddle behind the truck. But nothing.

So I turn it off, and back on, it returns to normal, then a minute later, the gauge drops again. I continue the day with the gauge working intermittently.

Since then it has only worked when I back the trailer into the water, and the connector gets wet. Leading me to believe it is an electrical issue, and NOT the sending unit that so many flamers on YT pointed out. Because, when its wet, it reads perfectly where it should, based on the mileage i have driven.
Of interest, the right turn signal on the trailer doesn't work when connected my car, but does when connected to my roommates.

Any ideas on where I should start looking for this gremlin?

Thanks guys..

[YotaFun]

Might want to mention what vehicle you exactly have.
Will really help us pinpoint this down since there was a TSB for certain year 4Runners.

On the off topic of the trailer, I have recently had the issue of both turn signals going on when I just activate one in the Truck, Someone else had this problem and it was tracked down to a bad harness for the hitch wiring

[yukon]

Might want to mention what vehicle you exactly have.
Will really help us pinpoint this down since there was a TSB for certain year 4Runners.

On the off topic of the trailer, I have recently had the issue of both turn signals going on when I just activate one in the Truck, Someone else had this problem and it was tracked down to a bad harness for the hitch wiring


Updated with year and model.

And I just finished reading your thread, might have to look into a new box it looks like. Unless someone else has any ideas.

[Bob98SR5]

all 99s and some 00s had gas gauge issues. The tsb that most likely addresses this is EL-010.

[yukon]

Again today. Plug the trailer lights in, Gas guage works, spot on too, Unplug, and a minute later it goes to empty again.

[CJM]

Could very wel be a short in the trailer wiring, have you checked it over thoroughly?

[MTL_4runner]

I've seen a few issues with the gas gauges but it sounds like an electrical connection in your case especially if the fuel gauge works only when you get it wet deliberately. Anyway, here's the info from the FSM for you. It doesn't look like the fuel gauge circuit is tied to anything but there may be a common grounding point for the rear lights and the fuel sender so that may be something to take a look at. Hope this helps.

[yukon]

Well, It doesn't only work when wet. When trailer lights are hooked up at all it works... I only have one trailer availible to try with so I haven't tried any others. Hopfully Ill get a chance to tear into it tomorrow. Also of note the Left trailer brake/turn light wont work on my car (not trailers fault). So I'll start there.


Will keep you all updated with what I find. Any one with ideas lets hear them,

MTL Thanks for the FSM pages!!

[bamachem]

does it work when the trailer lights are unplugged but the trailer is hooked to the truck?

my 99 had a weird issue where the gauge would ONLY work when the boat was hooked to the truck.

i thought it was a bad sending unit. replaced it, and it still happened. i did more searching and found that there's an incline sensor behind the instrument cluster that adjusts the signal from the sending unit based on the angle of the truck in reference to a flat surface.

i replaced that, only to continue to have the same issue.

i sold it before replacing the gauge.

there's only three parts for the gauge to function. sending unit, incline sensor, and the gauge itself.

best of luck...

[Crinale]

Have you tried changing the blinker fluid? :chair:

http://kalecoauto.com/images/BlinkFluid.jpg

:-P :wrenchin: :wrenchin: