fuel gauge temp gauge questions.

[itsabronco]

Should you be able to put a test light on the back of the gauge and get the pulsing light on the terminal that goes to the sending unit? Fuel gauge and temp gauge not working. Oil press gauge works. If i pull the wire off of it i get the flashing on the gauge terminal with a test light. LIke everyone else, Im goin nuts !!!

 

[Viperwolf1]

Flashing light would be normal. Check wiring to senders and grounds at senders. You can put your test light at the sender connector to check the integrity of the wire.

 

[itsabronco]

You say flashing light is normal. i did the check on my oil press. gauge and it flashed. fuel and temp did not flash. both dont work. so if i do not get a pulsing flash from the other side of the gauge, the gauge is no good? That is the conclusion I am coming to. Just trying to narrow it down in a simpler way than volts and ohms resistance...

 

[broncnaz]

Most likely its a bad gauge you can also check by grounding the wire that goes to the sending unit if the guage pegs to full then the sender or wiring is bad.

 

[Viperwolf1]

You say flashing light is normal. i did the check on my oil press. gauge and it flashed. fuel and temp did not flash. both dont work. so if i do not get a pulsing flash from the other side of the gauge, the gauge is no good? That is the conclusion I am coming to. Just trying to narrow it down in a simpler way than volts and ohms resistance...

Either gauges bad, gauges not hooked up to instrument voltage regulator, or wire between gauge and sender bad.

 

[itsabronco]

Either gauges bad, gauges not hooked up to instrument voltage regulator, or wire between gauge and sender bad.

cool pic viper. I think im going to remove whole cluster and send it in to the guy on here that does all the trick refurbishing. I was reading what he does and he says he re-gears the speedo head to be accurate. mine is 9 miles an hour off. If it says 70 MPH, im doin 61 MPH.

All the wiring is ok up to this point on the gauges. I did ground the wire, nothing happened. I do not have any voltage coming through the gauge. I have the power from IVR to all gauges but nothing coming out the other side.

Only thing thats messing with me is before i did an EFI conversion, temp gauge worked, and the aux tank quit, the rear still worked, then later the rear quit.

 

[Viperwolf1]

Speedo can be corrected with a new gear on the transfer case end of the cable. You need one with 3 more teeth.

You can ohm out the gauge. 10-14 ohms is good.

Sounds like the fuel sender switch is dirty. You can clean it with contact cleaner or take it apart and clean it up.

 

[itsabronco]

Good info on the speedo gear. where would I find one with three more teeth? I would have to take mine out and count how many teeth I have.

I will go get my bronco and figure out the ohms and remove and clean the switch for the fuel gauges.

Viper, saw your member of the month on CCB. Dont know how current it is. My buddy sent me a link. Congrats !

 

[Viperwolf1]

Thanks. That was last month, I think. I'm a slacker this month.

You can get the gears at the dealer. I think the max tooth number is either 20 or 21.

 

[itsabronco]

Allright, ohmed it all out. Aux fuel sender reads 71,and it is empty. Rear reads 13 and it is pretty close to full within a couple gallons. Selector switch is clean and works properly, good grounds at the tanks.

Zero ohms on the fuel and temp gauges. I hooked up fuel sender wire to the oil press. gauge, switched the switch, and it acted like a fuel gauge. I even poured gas into aux tank and watched the needle rise. Then took another reading and it was 17 ohms. I didnt fill it all the way. 4 or 5 gallons.

 

[Viperwolf1]

Gauges are bad.

 

[itsabronco]

Thanks Phil. I wasnt wanting to get into all the ohm stuff because I havent done that type of troubleshooting for awhile. Once I got going, it was fun. i was figuring stuff out left and right.

Now i have been troubleshooting the aux fan and ac relay on my sons J&&p ch&rok&&. Are you a wizard on any of that stuff? PM me if so. I do not want to get myself in trouble about heep ?'s on here !!!!

 

[Viperwolf1]

Thanks Phil. I wasnt wanting to get into all the ohm stuff because I havent done that type of troubleshooting for awhile. Once I got going, it was fun. i was figuring stuff out left and right.

Now i have been troubleshooting the aux fan and ac relay on my sons J&&p ch&rok&&. Are you a wizard on any of that stuff? PM me if so. I do not want to get myself in trouble about heep ?'s on here !!!!

How hard can it be? I say post it up. You've already related this thread to EB tech. And my pm box is always full. I have to go through it every couple days and make space.

 

[itsabronco]

OK, well I was checking why aux fan and AC not working. THere is power where the relays are, or should I say "was" power at the relays. I am talking about switched 12v that comes on when ignition switch turned on.

I pulled relays and was jumper wiring around to see if the fan worked, it does, and to see if ac clutch engaged, it does, and also the blower fan on the inside. It all works. But in the process of doing this, I lost the switched on power at the relays and havent found where to fix this issue yet. I obviously overloaded that circuit while messing around and blew a fuse or something. Everything (fuses) that I can find checks OK. I just dont know where else to look but im reseaching !

Im guessing that the relays are bad for one thing, the other problem is I dont have 12v from the battery where the AC relay plugs in. I dont know enough about the system but im learning !

 

[Viperwolf1]

You need a schematic that shows fuses and fusible links.

 

[Justafordguy]

I have seen this problem before on the Cherokees. They have a big fan relay inside the bumper and under the headlight that powers the fan and A/C. They are bad about burning out. You are supposed to take the bumper off to change it but if you take the headlight out (passenger side) you can see it. Then you have to cut out some plastic to get to it but after you put the light back in you can't see the part you have to cut. Good luck.

 

[itsabronco]

I have seen this problem before on the Cherokees. They have a big fan relay inside the bumper and under the headlight that powers the fan and A/C. They are bad about burning out. You are supposed to take the bumper off to change it but if you take the headlight out (passenger side) you can see it. Then you have to cut out some plastic to get to it but after you put the light back in you can't see the part you have to cut. Good luck.

That sounds like a pile of fun. . . %)