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Another gas gauge problem

S

SgtMajHarper

New member
City
Peyton
State
CO
I've read every discussion thread I could find and haven't been able to find the answer to my delima.

I have an 83 Scrambler that sat parked for @ a year due to some body work and tail light / turn signal issues. It ran fine when parked, gas gauge worked also. This last fall / winter I got the other work completed finally but when I got the Scrambler running now the gas gauge doesn't work. It just "ticked" up a little when the key was turned on, nothing else. I had a full tank of gas in it when parked, checked the hot wire going to the sending unit and had power, thought maybe the sending unit went bad or the float sank to the bottom and read empty. So, I ordered a new sending unit, dropped the tank, pulled the old sending unit, float had "some" gas in it, not much or enough to be my problem. I tested the old sending unit and all readings were good. So, I put the new float on the old sending unit and put the tank back up, went and filled it up, gauge still reading empty so I figured the gauge went bad/ I got a new Rugged Ridge gauge, installed it, made sure the wires were correct.

Now when the key is turned on, the fuel gauge goes from E and pegs hard left below E. In the off position it returns to E like normal. Same when engine running or just key on. Someone somewhere had a post saying that the polarity was reversed on these after market gauges (sounded odd) and to reverse the wires. I had tried everything else, so I figured I'd give it the smoke test. Didn't make any difference, did the same thing. I put the correct wires back where they belong with the same issue and I am befuddled.

I keep reading remarks about they never work, get used to it, etc....... I've had Jeeps since the 70's and they all has working gas gauges, some were even replaced, but they still worked.

Ideas?
 
Yes, temp. gauge works. It never worked well in my opinion, it always reads a little on the cold side, but I think that's a thermostat issue as I also get little heat. but for this issue it seems to be working same as it did before.
 
Check the voltage at the temp gauge side of the "jumper strap" that comes off the gas gauge. It should be like 5-6 volts. If it is reading full 12 volts, the CVR in the gas gauge took a dump and just a matter of time before it fries the temp gauge, too.

Check grounds, too.
 
When I dropped the tank to check / replace the sending unit, I checked the ground and sending unit connections, all looked good. I checked the dedicated ground going to the dash cluster, it goes to the housing for the windshield wiper switch, looked good and then I ran another dedicated ground wire to the body connecting it to the other ground and back to the gauge cluster.

I tested the voltage on the gauges:
pink wire on "S post" on fuel gauge is 1.99 volts,
red wire on "I post" on fuel gauge is 11.82 volts,
purple wire on "S post" on temp gauge is 11 volts,
red wire on "I post" on fuel gauge across "jumper strap" to "A post" on temp gauge is ZERO volts,
just for fun, I checked pink wire on "S post" on fuel gauge to "A post" on temp gauge is 12.6 volts
pink wire on "S post" on fuel gauge to purple wire on "S post" on temp gauge is 11.8 volts.
"A post" on fuel gauge across "jumper wire" to "A post" on temp gauge is ZERO volts.
I checked the voltage of the wire going into / out of the sending unit in the tank at 2 volts.

Now when I turn on the ignition, I get no movement at all from the fuel gauge......I imagine by now I have fried it screwing around.

My head hurts......but when I read about guys messing with their brake light switch under the dash, I don't feel quite as bad.... barely better.
 
Hey SgtMajHarper,
Challenger here just west of you in Loveland CO. PM me your number, maybe we can get together and figure this issue out.
 
Hey Challenger.....thnx for the offer of assist. Not sure your availability status, I'm wrapped up tomorrow (Sunday) hanging blinds at the daughters new place so wife my issues have to wait. I'm usually available weekdays after wife get's off to work and I'm temporarily left in charge of myself.
Here's where I stand on the project "currently".

I thought I'd save some grief and time and bit the bullet and ordered and NIB Crown speedo with new gauges installed. I installed it after finding some instructions on the internet (it had extra connections on the gauges), turns out they are for grounds. I put it in and noticed the gauge face sat crooked inside of the housing (odd). Put everything back together, fired it up, gas gauge moved up maybe 1/8 tank, after running 15 min. temp gauge up to 3/4 max. I drove it, speedo slow by 15-20 mph depending on true speed.

What a piece of junk! Took it out, ordered new replacement fuel and temp gauges and am ready to put them in.

I'll fire you off a number when I'm home ready to get back at this hopefully Monday morning and you can call when ready. Thanks......I really want to finish this as I have "other stuff" needing attention.

Have a great weekend.
 
Just be wary as i believe the aftermarket gauges are 12 Volts powered and do not rely on a regulator in the fuel gauge anymore so if you are buying new aftermarket ones then ensure you swap both temperature and fuel gauges.

Assuming the gauges have nbever been changed then with the ignition switched on you should have:
I Post on fuel gauge should give you about 12 Volts to ground (which reading your post it does)
A post on either fuel or temp gauge should have about 5 Volts to ground, if its 12Volts then as @spankrjs says the regulator is blown and that will fry your original gauges.

The wire from the fuel sender (think its pink) should read between 73 ohms if tank is full to 10 ohms if tank is empty, test between a ground and the wire make sure its not reading your body resistance when doing this as well by not holding the probe on with your fingers.

The wire from the temp sender (think its purple) should read between 73 Ohms (or more) when cold and 13 Ohms or more when engine is overheating.

Make sure there is a good ground on the speedometer casing and there isn't a lot else to it.

Hope this helps!.
 
I'm planning on getting back at it tomorrow. Starting with looking over the new gauges, the old ones have been replaced before. Checking out voltages on wires, sending unit etc. then I'll have my current base line of information to see where I am at.
 
Hey guys, thanks for all the help on this so far. I am going to have to wait until work and other stuff at home settle down a little. I'm still hoping for this month.
 
Update....first of all, thanks to everyone for the help and offers of help. I like "tinkering" on things and knowing how they work, should work, shouldn't work, etc. This was a bear for me, maybe too may other issues kept coming up, getting frustrated when "bolting on" a new part didn't fix the issue. Anyway.....I finally reached a point of how much longer am I going to keep messing with this and getting more frustrated or just bite the bullet and "take it to someone"?

I caved, I waved the white flag of shame in surrender and "took it to a guy", they run a professional shop here in town, in fact the same guy I bought the Scrambler from many moons ago.

They put in after market separate gauges under the dash where the ash tray was mounted. They match the other original gauges, look fine and best of all they work.

They did however scare me when they called a day after dropping it off....figured, great, big bucks, big problems...nope, they just had it done in half a day.......I screwed around with it for months on and off thru the winter, invented new swear words, used other swear words from replacing the brake light switch. Anyway, all fixed now and back on the road in good order.

In the mean time I was looking at the reflector in the center of the spare tire rack and thought it would look cooler as a 3rd brake light. That manifested into a "flashing strobe" 3rd brake light. Ill finish with it today, but gotta tell you all.....I really do like that flashing strobe brake light, does exactly what I wanted and looks pretty cool.

Thanks again for the help guys!!
 
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