Help, my gas gauge is permenantly on E! (1 Viewer)

[Doc]

Help, my gas gauge is permenantly on E! UPDATE

When I bought my 60 two months ago or so I thought is was empty. I took it to put gas in it, and it only took $0.50. It was full.

OK, buy a new fuel level sending unit, right? I took my sweet time about getting one, and just filled the truck up every 150 miles or so.

The new fuel level sending unit arrived today. BRAND NEW. Put it in. Still on E.

So I then tested the old FLSU with my multi-meter. On the resistance setting, there was no sweep of the hands. With the NEW unit, the hands swept all the way to the right, (no resistance, right?) So I take it to mean the old FLSU was bad, and the new one was good, but why then do I not get a fuel level on my gauge?

If I run two wires from the top of the new FLSU to the back of the gauge will that make it work?

I'm an electrical idiot, so any and all help would be appreciated.

Yes, the gauge is plugged into the harness behind the cluster.

 

[johnny4ever]

it aint got no gas in it.

 

[saint60]

even though the guage is plugged into the cluster i would check to make sure it is getting the signal with a test light. you could have a loose connection somewhere or something. it is like that all over one of my cruisers. everything is hooked up, but nothing works. hmmm. it's worth a try.

 

[dogboy2]

Help, my gas gauge is permenantly on E!

well, what were you expecting? it is a Land Cruiser after all, not a Prius

just funnin' ya Doc....seriously, you might have a bad gauge, a short in the gauge wiring, a corroded connection along the line......basically, a can of worms that logic, a good wiring diagram, and a whole ton of patience can tame. Start with what you know to be functional and work backwards from there.

hth,
-dogboy- '87 FJ60

 

[Doc]

I'll pull the cluster today sometime. Does anyone have an EWD for this? I don't have a FSM for the 60 yet.

 

[archie]

I believe that most gas tanks have floats that go up and down with the gas level. It could be that this float is stuck on the bottom, in addition to your guage being busted.I am not sure about your vehicle having this float but you can investigate further in this direction.

 

[Doc]

I have replaced the entire fuel level sending unit, part of which is that float you are talking about.

I'm pretty sure the old FLSU was dead, so apparently it's only PART of the problem, now that I have a new FLSU I can track down the other issues.

I was going to loan the 60 to a friend for a tip to colorado next week, but don't feel safe doing so if the gas gauge doesn't work. I just fill up according to the trip meter, but they may not feel OK doing that.

 

[dogboy2]

Does anyone have an EWD for this? I don't have a FSM for the 60 yet.

try: http://www.birfield.com/

you can download the Chassis-Body manual which should have the wiring diagrams (at least the hard copies come with them)

-dogboy- '87 FJ60

 

[Doc]

Should the two wires going to the top of the FLSU have voltage?

 

[xrock]

I just bought a 60 in Salt Lake, Ut and immediately drove it back here to Phoenix with a faulty gas gauge. You just have to make sure you hit the tripometer everytime you fill up!

 

[Doc]

^ That's what I do now, and have been doing for two months. But I'd like to have a fuctioning gauge.

Anyone?

 

[60wag]

The wiring from the FSM is: WB (white w/ black stripe) wire is grounded. YR (yellow w/ red stripe) goes to the fuel gauge. The in tank sender is a variable resistor. Empty should be 120 ohms, full 17 ohms. Since you replaced the unit, I doubt its faulty. I'd check the WB ground and check continuity of the YR wire between the sender and the gauge. To test the gauge itself, put a 3.4W bulb in place of the fuel sender - one side grounded, the other on the YR wire. From the FSM "after the ignition is turned on, the bulb should sart flashing, and the gauge needle should vibrate." HTHs.

edit: one more thought..... since the gauge is stuck on E and E is higher resistance on the sender than full, a faulty wire connection would point to E rather than Full.

 

[Doc]

Thanks 60wag. I don't remember having a white wire with black stripe, but I'll double check.

So no wires have voltage on top of the FLSU? That's good. Because neither one had any when I tested them. Probobly a bad ground. I'll snoop around more tomorrow.

 

[fergus]

Sounds like the sending unit ground.I thought it grounded through the screws and into the flange on the tank.

Good Luck!

 

[Doc]

Ok. I pulled the cover off of the FLSU, the two wires plugged into the FLSU head out the back- but when I crawl under the truck I see no wires coming off of the top of the tank, either to the rear or the front of the tank.

Maybe they got cut. I'll have to do some more digging, it was just a quick look before brunch. They might just be tucked up out of the way enough that I can't see them. I'll tie a long wire to them and see if I can push them through to where I can see the exit point. If I can find the grounding point I think I'll find the problem, as stated above. There's so much rust under there that the ground screw has probobly completel rusted away.

The rear bumper cross member nearly doesn't exist anymore because of the stuff... I need a new bumper!

 

[Radd Cruisers]

I think he is speaking of the ground that comes out of the harness to the sender that screws into the flange and the plug in is connected.

Seems simple but did you make sure you have good clean contacts at the tank, seems like 9 times outa 10 thats the problem.

Rob

 

[Doc]

Here's what I found out this afternoon:

the wires exit on the drivers side of the tank, on top. They go to the interior wall and into a cluster-plug in behind the rear window washer bag. There are two wires going to the FLSU on my 1987 FJ60 One is yellow with a large red stripe, the other is solidly brown in color. When the two wires reach the cluster plug the brown wire goes through and becomes brown with blue dots. This wire goes back through the wall and grounds to a screw with a large white wire with black stripe that is the ground for the tail lights. This ground is still good.

The yellow wire with red stripe goes through the cluster plug and continues on to the front of the vehicle as the same color. It runs un-interupted until you get to another large cluster plug just under the gauge cluster, above the clutch pedal. Again, the wire passes through without changing colors or markings. This continues up to the gauge cluster itself.

I used both a 3W and 5W bulb to test the wire itself. I cut the plug off of the wires on top of the FLSU because they looked corroded. Before making new plugs for the wires I used both a 3 and 5 W bulb to test the gauge. Neither bulb lit.

I interpret this to mean that the fuel gauge itself has gone balls up. Correct?

Anybody have a cluster to sell? I just need the leftmost set of guages.

 

[Doc]

Sidenote: I think the wiring to the FLSU is still good. All the large cluster plugs looked solidly connected, and if they wren't I'd be having loads of problems, not just this one, right?

It's wierd that the gauge and FLSU would both be bad. But, who knows how long it's been since that thing has functioned. One went first, probobly years ago- then the other finally gave up. I bet the FLSU went out first, and the cluster finally gave out from lack of use... maybe not. I'm no electrical guru.

 

[Doc]

I recieved my new gas gauge in the mail yesterday. OK, used, but new to me.

Same problem.

So, the ground is good. The wire from the top of the fuel level sending unit is good. The fuel level sending unit is NEW, and the gauge probobly works.....

Is there a power source for the gas guage? I need to check that next I guess.

I'm running out of idea's here.

 

[60wag]

Bummer. Do you have a FSM wiring diagram? Here's one from Birfield: http://www.birfield.com/manuals/cb1980/13_71.htm The diagram shows the power going to the gauge assembly. There is a voltage regulator between the power and the gauge. I think the voltage regulator is common for the temp,fuel, and oil pressure gauges but am not positive. I've read posts in the past where gauge problems have been traced back to dirty connections at the voltage regulator. The problem is, all the gauges go wacky at the same time. Now this MIGHT be related to your overheating issue or maybe not. Do a search for gauge voltage regulator posts both on IH8mud and the LCML archives on Birfield. Somewhere in there you'll find comments on the symptoms and repair of the voltage regulator. On the overheat issue - has the rad ever boiled over or just shown hot on the gauge? If you can check the engine temp with a IR thermometer or some other independant device you could confirm that the dash temp gauge if giving you good info. HTHs.