Newb with gas gauge question

Hello,
My girlfriend picked up a new (to us) cj5. It's a '73 with a rebuilt 258 and a 4 speed. Here's a pic



The fuel and temp gauges don't work. I'm pretty sure they are fried. I did lurk around and find some test procedures on here. There seems to be enough info on this site to make my head spin. I'm sure I'll need about most of it.
Anyway my question is this. I'd like to just put an aftermarket gas gauge in the dash. Is there one that is recommended over the others? I did see it needs to be in the 10 to 73 ohm range.
Thanks

 

Nice looking rig you got there!

I'm still trying to get my factory style gauges to work.
I do have a bit of advice in that when you install the new sending unit, make sure to check its function and range on the bench befor reinstalling. You need to bend the arm and stop tabs so you get a valid reading on the gauge for the float postion.
I need to drop my tank to adjust the stops on my sending unit. The new aftermarket senders have stop tabs that need lots of tweaking to allow the full sweep from empty to full.

 

Hmmmm, I was planning on using the sending unit that's in there as it seems to be reading correctly. If I go with an aftermarket gauge, do I need to use an aftermarket sending unit too?
Also, it turns out the project Jeep we're trying to sell has a Stewart Warner fuel gauge in it. I was thinking on just taking that one out. I don't remember it ever reading above empty. Is there a way to test it before I put it in the new Jeep?

 

She picked a good one.

You might try these web sites for more troubleshooting info on stock gauges.

http://www.jeepfan.com/tech/understanding-and-troubleshooting-jeep-cj-gauges-and-senders/

http://home.roadrunner.com/~john.strenk/Gauge%20web%20page/basic_troubleshooting_for_cj_gau.htm

Otherwise, most any 73-10ohm gauge should work with the existing sender.

BTW, where are you located?

 

i also have a new sending unit that i got from turner... how does one go about bench testing the gauge?

both the sender AND the gauge are out of the JEEP...

hook 12V battery and ground thru the gauge and check the stops vs reading?

 

Check my links in the post above, they explain bench testing. I think they'll help.

 

Do make sure that the replacement sender float is not the junk plastic one as it's likely to fill up with gas over time...if yours has the plastic one, swap it out with the brass one

http://walcks4wd.com/sending-unit-brass-float-all-m.html

 

Nice Jeep. The 258/T-18 combination was very popular with customers in the day. It's a very reliable and durable combo.

Are you on familiar terms with a multimeter? I suggest you try and fix what you have. You may regret cutting a hole in the dash for a new fuel gauge - I know that I would. If you must fit an aftermarket gauge, I'd suggest using an under-dash gauge cluster, available from a speed shop or online at Jegs or Summit Racing.

You can buy the brass sender floats separately if your float has sunk. They are a Ford part.

 

I'm showing 12 ohms from the sender. I think that's pretty close as I just filled it recently. I took an aftermarket SW fuel gauge out of the flattie we are trying to sell. On the bench this gauge seems to work. For the time being I'll stick it in the ammeter hole as that gauge has nothing going to it. Then I might buy the matching Stewart Warner gauges after that. Somebody already drilled some smaller holes in the dash so it's no longer virgin. They were for some heater controls. Those were originally under the dash, right?
Oh and I'm in Colorado. Guess I should tend to my info on here.

 

Yes the heater controls were under the dash.

Oh...welcome to the forum.

 

WOW!! your girlfriend bought the jeep... some guys just have all the luck. lol

 

I know right?

 

Quick question, with the Jeep off I'm showing 13 ohms at the sender wire. That sounds about right as we've been driving around a bit. The SW gauge is only going up to about an 1/8 of a tank though. I'm not really sure if this gauge is for a 10-73 ohm range, so I'm assuming it's either the incorrect gauge or it's broken. Does that sound right?

 

What did it measure when it was empty?

Try some fixed resistors across your gauge to test it. That's how the TSM tells you to test, but they use a fancy Jeep special tool resistance sub box. You can buy a whole bag of resistors for a few bucks at Radieux Shaque.

 

Radieux Shaque, lol.
We used some resistors to try and test it at work the other night. We had this SW gauge and a stock gauge we were playing with. The stock one had a wire broke and man is that some thin wire! The SW gauge seemed to work but it reacted very slowly, I mean veeeeeeery slowly. Yesterday, the second time I drove the Jeep after replacing the gauge, it made it's way up to half. So I think the Stewart Warner gauge is bad too.
I also found the stock fuel gauge for the 49 willys that my girlfriend has. Would that have been 6 volt?

 

Yes 6 volt for the 49 so it will burn up on 12V. On the SW gauge, some units worked in reverse. The jeep SW gauges would show empty when the sender was at 73 ohms and others would show empty at 10 ohm reading. There were gauges that went to full when turned off and move down to proper fuel level when turned ON. When you try to mix and match, you will usually run into a can-o-worms unless you are good at electrical theory and love to tinker.

 

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Good looking '5 you got there.

Any updates?

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