Gas gauge went from about 1/4 to full in about 3 seconds and hasn't moved since. 2000 B3000 Mazda 3.0 V-6 auto. I've checked all the instrument cluster fuses (11,26,33). I know of the method of disconnecting the connector at the gas tank to see if its the sending unit or the gauge but I can't see or feel in there good enough to do that. Would either one go bad that quickly? Doesn't seem likely to me. I've read about a "slosh sensor" in a post on this forum - does my truck even have that? I've had an intermittent wiper problem a couple of times but the multifunction switch wouldn't be involved would it? I'm just trying to see if there might be a simple fix before I add it to my repair list when I take it to have the ball joints replaced. thanks

 

Open in the circuit to the fuel level sender.

 

Have a look here for the pinpoint tests. https://www.ford-trucks.com/forums/1...tml#post752678

EDIT: Have a look here for wiring diagrams & color codes. http://www.revbase.com/BBBMotor/Wd

It's easier to unfasten the fuel filler & rear wiring harness connector, unbolt & move the bed back to get at the fuel pump electricals, than to drop the tank.

 

Thanks wtroger and especially pawpaw for quick feedback. The troubleshooting links were good pawpaw and at least now I know it's fuse #11 thats for the gas gauge-that's a big help in itself. Why they don't identify a fuse for a certain gauge instead of saying instrument cluster in general is dumb. I may not can fix it but this certainly helps. Thanks again - I consider my question answered.

 

On the windshield wiper random spooky operation, I know this is a 2000 Mazda B3000, but they were built along side Rangers, so probably have the same replacement program as the Ranger 00B40 multi-function switch replacement program that I got a letter on from Ford & it didn't have an expiration date on it, so have your VIN # looked up to see if it qualifies for a no cost replacement, if it hasn't already been done.
Here is a link to a thread Rockledge started on the subject, in which he posted the letter to affected Ford vehicle owners.
Bet there was one for Mazda too, as they used the same parts as the Ranger. https://www.ford-trucks.com/forums/2...on-switch.html

There are members that have posted taking the multi-function switch apart to clean the corrosion off the contacts, re-lube & reassemble the switch with good lasting results.
A search should turn up some of the threads if your of a mind to try that, as a new switch is expensive.

Let us know how it goes.

 

I would have expected there to be a short in the wire from the sending unit to the dash gauge.
If you ground the wire, doesn't the gauge go to FULL? Or is it backwards from the other gauges? The temp gauge on a Vulcan 3.0 goes to full HOT if the connector is grounded.
I can't say about Rangers, but there is a common problem in F150 types where the wire leading from the MF switch gets stretched as the steering wheel is tilted up & down. I think(memory? What?) that the turn signal quits working properly, and becomes sensitive to bumps, motion, etc. Can't say that the same applies, but one would wonder...
tom
tom

 

These models short the wire to ground and the gauge goes to empty. Backwards from what it used to be. Usual suspect is the connector on top of the tank.

 

Thanks again. So multifunction switch may be involved. I still can't get to top of tank very well but will try again. In meantime I checked voltage on fuse 11 which was 11.2V on both sides(fuse good) and ohms which was 15ohms to ground (body) on both sides. Ohms reading seems too low to be reading through the gauge and sending unit to ground. I was expecting to see infinity or megohms at least. Hope this will help in troubleshooting. Happy holidays.

 

Quick update. I called my local Mazda dealer in Knoxville today and they claimed there were no recalls on my truck at all-MF switch or otherwise They did look up my VIN. I have had trouble with it like I said and once the radio stayed on with keys out. Is the MF switch even an issue though. From what I can tell from the wiring diagram you simply have battery voltage going thru the fuse, the gauge and the sending unit in the tank to ground. Is this not correct? I need to get to the tank connector-is there any way to lay on one side or the other of the truck with it on the ground and get 2 hands on it-or is this nearly impossible? Does it have to be on a lift? thanks again

 

take the four bolts inside the bed out,,, underneath the back bumper is a connector for the tail lights un hook that,,, take the 3 screws out around the filler neck on the gas tank and get some one to help ya lift the bed off truck,,,, it will be a lot easier to get to the gas tank and connections than from underneath,,,, if you have a long bed it may be 6 bolts,,,bolts usually hex or torx,,,,,the whole bed is not very heavy mine is the long bed and it just takes 2 of us to lift it off and set on ground,,,,