Gas Gauge

[fear0fish]

I have a 82 FJ40 and the trip meter been sticking tried to rebuild it but couldn’t remove the speedometer needle so I just used PB blaster and lube it up real good it’s working better. In all the taking apart and re installing ( 12 time are more ) everything worked fine, but now the gas gauge and temperature gauge stopped working. When I first start the engine the gas gauge comes up and seems accurate but after a minute are two it goes dead, something it will work for awhile but when it goes dead so does the temperature gauge. I have taken it out and clean any contacts thinking it’s a ground issue, any ideas what I should try next.
Thanks for any help

 

[John McVicker]

Always disconect the batt. prior to removing gauge cluster. You already know this if you've done it 12 times, but others might not be aware.

Had the exact same prob w/fuel gauge & for the same reason...removing the cluster a bunch of times. I will describe what my solution was...it has been a week & so far so good.

I know there is a better/proper way & if you or someone else can post 'the' proper way I would be grateful. But this was easy...worked and in the long run was less likely to damage the cluster/harness that plugs into the back of the speedo cluster. At least w/my limited electrical skills.



My solution was to put 1 strand of 10 gage wire into the hole in the connector marked # 1 that slides onto the 12 or so pins on the back of the speedo cluster.



# 1 pin is the ground. After much trail and error, I was able to determine which connector was loose (yours may be different), I tried to squeeze the connector to make a tighter fit but was afraid I would break it and really be screwed. I tried 2 strands of 10 gage, but it was too tight & I couldn't fit the harness over the pins. One strand about 1/4 inch long, stuffed in the hole worked. Figure out which pin is not making good contact & either squeeze the connection tighter or try my method.

So far it has stood up. Yesterday I went on a ALL day trail ride, 4x low, bouncy, bouncy & still working....BUT if someone has a more traditional way, please post.

John

 

[imabigbangkindaguy]

Hahahahaha, that is awesome that it worked and is still working!! I am going to try that in the morning! See if I cant fix my gas/temp gauge issue.

 

[John McVicker]

Hahahahaha, that is awesome that it worked and is still working!! I am going to try that in the morning! See if I cant fix my gas/temp gauge issue.

The hardest part was to isolate/determine which connection was the problem. I was by myself, a helper would make it much eaiser.

To determine which connection was loose you need 12v, so the batt. has to be hooked up (be very careful to not touch the amp connections to any metal). One hand pushing the round cluster tight to the pins. The other hand wiggeling each wire , one at a time to determine which is loose. Then you need to be able to observe the fuel gauge to determine which wire gets it moving again. The speedo cluster is resting on the steering col. in order to give you room to have both hands inside on the cluster/pins. I put a hand held mirror between my knees to be able to see the fuel needle move. Strange I know.

I am guessing your loose wire could be the ground wire # 1, or maybe the fuel gage wire which I 'think' is # 4.

John

 

[imabigbangkindaguy]

GRRRR, had no luck!!!! But I did not have a helper with me, perhaphs next weekend I will recruit some of my nephews.

I cleaned all the contacts, took the gauge out and cleaned the contacts in there, when I put it back together and back in, the gauge worked for about ten seconds, then right back down to zero.....

Maybe next weekend, as I have run out of time, again...

However that did not stop me from driving her around and taking her to the Red River Shoot Out, where Texas, seemed like they were uninterested in playing..... and lost again.....

Oh yeah, all the fuses are good, I replaced every single one, and as far as I can tell all grounds are good too,with no broken wires...

 

[1911]

Check the little metal tab on the back of the fuel gauge (looks like a male electrical spade connector) that is the only grounding connection for the fuel and temp. gauges. It must be clean and make good contact with the gauge cluster housing.

 

[imabigbangkindaguy]

Check the little metal tab on the back of the fuel gauge (looks like a male electrical spade connector) that is the only grounding connection for the fuel and temp. gauges. It must be clean and make good contact with the gauge cluster housing.

Thanks, 1911, but sadly, that too was done. I am really stumped.....

 

[1911]

Last time I had my cluster out, I made a jumper wire for the little tab and screwed it to the cluster housing. A female spade connector (crimped a little tighter) worked perfectly.

 

[imabigbangkindaguy]

Hmmmm, thats an idea, thank you, I will give this a try as well on the upcoming weekend.

 

[John McVicker]

GRRRR, had no luck!!!! But I did not have a helper with me, perhaphs next weekend I will recruit some of my nephews.

I cleaned all the contacts, took the gauge out and cleaned the contacts in there, when I put it back together and back in, the gauge worked for about ten seconds, then right back down to zero.....

Maybe next weekend, as I have run out of time, again...

However that did not stop me from driving her around and taking her to the Red River Shoot Out, where Texas, seemed like they were uninterested in playing..... and lost again.....

Oh yeah, all the fuses are good, I replaced every single one, and as far as I can tell all grounds are good too,with no broken wires...

If you got it to work even for 10 sec. you know you are on the right track, just keep fiddling with it.

Try 1911's spade trick, if mine quits working agajn that's what I will do. My fix is still working. But b/4 I came up w/my 1 strand of 10 gage wire solution mine would do the exact same as yours. Ie. I would move the wires, get the needle to move while the cluster was upside down...but as soon as I would put the cluster right side up...maybe it would work & maybe not. Sometime even work for several days, then quit again. But my 1 strand wire solution has held up for several weeks now.

Like I said, you are on the right track, you've got a loose wire somewhere, gound or hot...keep at it.

John

 

[bsmith123]

gauges

I looked at the 82 schematic

The gauges share power and get their grounds from their respective senders (the senders vary the resistance to change the reading)

so I bet the brake warning isnt working either---the temp gauge gets power then it goes on to the fuel gauge---I am guessing this is a circuit board here? if not same principle applies but instead of solder check the wire and/or splice off

not sure cause mine is a 71---look closely for cracks in solder if it is--you may need to solder in a little jumper or run a new line

since 2 gauges are involved I think you can rule out an individual sender

also 2 checks you might do here

run power to each gauge individually with a jumper and see if it reads

touch the ground side to ground and then take it off and see if the gauge pegs

 

[imabigbangkindaguy]

Ok, looking for some more help in this area, I decided this weekend to tear into the gauge cluster and fix this issue, the driving issue for this was that my guesstimation of fuel amount, failed on me as I ran out of gas, right in front of TCU this past Monday. Felt like a kid agian calling good ol Dad to come and bail me out, and he reminded me that his landcruisers fuel gauge was working just fine, gotta love the old man. Long story short, after putting in half a day on Saturday, I HAD NO LUCK!!! So I am begging, pleading for different ideas, or possible reasons for these gauge to not work.

Would a bad fuel sender cause both of them to not work??

I have both gauges out, and they test properly for ohms, and when I attach a 9v battery to them they both respond by pegging out.

The Fuel sending unit, has a proper ohm range for full and empty.

I checked behind the gauge cluster, and every wire is properly connected. I used my multimeter, and was getting a power from the back of the temp gauge.

I was getting a confusing signal from the fuel gauge, I would get a signal from the left and the upper middle post, but no signal from the left and the right post.

I thought the left post was 12v power, the middle post was the voltage regulator to the temp gauge, and the right post was to the fuel sending unit.

Is the above correct?? If so anybody know what that means??

I am sure the answwer is something simple that i am just not seeing, I hope I have provided enought detail for everyones brain to start working... and maybe that will rub off on mine, and i can get this sorted out!!!