I give up what the fawk is the problem here!!!! I know this is not a hardcore wheeling problem, I am sure somebody will say use a stick, carry extra ect, ect, but dammit I have everything else on this thing working PERFECT and now I don't know how much fuel I have...

I just dumped a 115 bucks into a new speedo cluster to fix my fuel guage, the sender is new, it is calibrated correctly but the guage is not reading correctly.

On the sender side I have 35 ohms of resistance and my guage is BARELY off of Empty when I know the tank is just below half, it was my under standing the 73 ohms is empty 9 Full. At 35 ohms I think I should be pretty near the middle of the scale. I grounded the guage and it reads full so it is not stuck, when you turn the key off it falls below empty.

Did 4wd Hardware sell me a faulty cluster, keep in mind that this is NOT the 3 wire fuel guage with the regulator, this is a two post calling for 12v switched on one post and the sender on the other.

One other thing, I do not have the temp guage hooked up to a sender due to my V-8 swap could this in some way mess it up with the new style independent 12 volt guages....

Thanks... don't flame me I have earned the right to ask one newbie question... :D

more CJ guage tech than should be allowed

Originally posted by Mo
more CJ guage tech than should be allowed

Where???? :D

He's probably talking about Jaffer's site....


http://www.monsterslayer.com/jeep/Gauges.htm

Originally posted by AtomicBeesting
He's probably talking about Jaffer's site....


http://www.monsterslayer.com/jeep/Gauges.htm


Hmmm, read that one, my guages are different but all the checks work out okay! :mad:

Originally posted by AtomicBeesting
He's probably talking about Jaffer's site....


http://www.monsterslayer.com/jeep/Gauges.htm

uh.... yeah... I had the page open, guess I forgot the link :emb:

Originally posted by TPIJeep

On the sender side I have 35 ohms of resistance and my guage is BARELY off of Empty when I know the tank is just below half, it was my under standing the 73 ohms is empty 9 Full. At 35 ohms I think I should be pretty near the middle of the scale.
Did 4wd Hardware sell me a faulty cluster,

Hmmm, read that one, my guages are different but all the checks work out okay!



OK ...
First of all your sender should be metering about 20 ohms resistance at "just below half" ... not 35
Sounds like a corroded sender wire and/or sender's ground wire problem. or even a bad sender.
Bad connections give higher resistance readings.

Now, since you say your gauges are "different" you need to state different because of the direct to each gauge 12v. wiring or different because the H & C and the F & H are backwards to this ...

http://www.monsterslayer.com/jeep/images/SpedoPic2.GIF

If they are backwards, it means they are still putting the crappy, inported VDO gauges in those speedos and you are lucky they work at all.
The best gauge sets come from your Jeep dealer or from FWD Hardware under the listing as "OEM Replacments" which are the real McCoy Stewart Warners.

I heard second hand a while back that FWD Hardware was having so many returns of their speedos that it was one guys job to take out the VDOs and replace them with the S & Ws.

The combination of bad sender wiring (or sender) and those cheap imported gauges is enough to drive anyone crazy.

Ya just should have followed my advice (in the gauge article) in the first place ...
"When ordering replacement Fuel and Temp gauges for your Speedometer cluster, Stewart Warner brand "factory replacements" (Mopar # 4740791) are considered the best. These have "C" and "H" as well as the "E" and the "F" in the stock OEM orientation.
Note: Imported, after-market gauges have these ranges reversed.
Both replacement brands are dual 12 volt units and have different wiring and post setups. "

take a look at the ground, Mine did the same thing but hte ground from the tank was all jacked up..

Can you say "AUTOMETER"!

Jaffer,

Thanks for answering this thread. The guage set I have has the guage terminal as follows, looking at the back of the speedo with the guages on the bottom... fuel sender / 12v+ / temp sender / 12v+ and the two 12v's have a jumper wire between them.

The guage panel I took out has the real deal stewart warners in there and it looks exactly like the panel I just got. I wish I could look up in there and see if they were SW guages but I am not about to take the new panel apart and void any chance of returning it..

Here is my question to you, the sender is new, it checked out correctly before I installed it, the ground is good. I am not 100% sure how much gas is in the tank but the sender lead is pulling 35 ohms where do you think the needle should be pointing? I would think it should be higher than splitting the E line?

Thanks.....

:)

Edit: I just went and put about 2-3 gallons in the tank and the ohms dropped from 35 to 29 so the sender is free and working and there was minimal change in the needle posistion.

The backward Hot/Cold Full/Empty markings are the key to telling if they are imports or S&W gauges. Read my earlier post again ...

You need to elimimate the sender as the culprit by metering the sender at empty, 1/2, and full tank.
CJ spec ...
* 73 ohms Empty
* 23 ohms at 1/2 tank
* 10 ohms Full

You can use resistors from Radio Shack to simulate the sender.
I've even used the CJ's heater resistor coils as a tester ... each of the two coils has 15 ohms resistance.

Then, if you are sure sender registers close to spec and the gauge won't display the correct reading it's time to get a set that does.

Mine has a new sender, wiring, and a new set of Stewart Warners and it registers perfectly.
It even bounces around a little at 1/2 tank due to slosh.

There's no reason why anyone's CJ gauges can't work as well.
You just have to work at making sure everything is doing it's job.

Is the float adjusted correctly? If it is on the short side, it will read empty when it is partially full.
BTW, I run outta fuel when my gauge reads 1/4, I just got used to it.

Originally posted by JeepinIan
Is the float adjusted correctly? If it is on the short side, it will read empty when it is partially full.


Yeah, this is the often the case.
And a lot of times because a standard sender is put into one of the OEM optional 20 gallon tanks.
It wasn't until just a couple of years ago that you could get the oversized tank sender with it's longer arm.
One can avoid a lot of trouble by testing the sender while installing it.

In Ian's case where the meter is reading HIGHER than the actual fuel level, one can add a resistor to the sender wire to bring the needle back down to Empty. I'd start trying 10 ohms.
The higher the resistance, the lower the gas reading.*

*YJs are the opposite of this.

Let me know I am having simmilar issues with this

BTW, I run outta fuel when my gauge reads 1/4, I just got used to it.

Mine reads the same after I installed a new sender unit.

I might try the adding the resistor to the sender wire like Jaffer said.

Let me know I am having simmilar issues with this
If he still hasn't figured it out after four years, do you really think he's going to have a solution for you?

(My guess is that he's probably not "still working on this.")