denlem

Must be something in the air... My Trailblazer has just started going bonkers too. Some days it will read properly, other times it just keeps going higher and higher and even goes all the way around. A few days ago when I took this pic I was in park doing 115. Nice!

The Trailblazers has a stepper motor for the speedo that needs to be changed. Not sure if the Mustang speedos are the same or not, but it's something to look into.

Mxyzptlk

This morning I reflashed tune back to stock and disconnected the battery for 15 minutes. I normaled everything backup and reapplied the tune and the speedo works. Im thinking maybe the battery is low, i have had it die one me 3 or 4 times in the past 6 months. Gonna buy a new one and hope for the best.

Whats this passenger side water leak you guys are talking about? It was raining the last time I drove the car the other day.

Mxyzptlk

I have replaced the battery and OSS sensor and still have this issue. Its only happening when the temperature goes below freezing that the speedometer is failing. Im fearing Im left to pay the dealer again on this on.

DADS05

I have an '05 Mustang GT. I am having problems with my fuel gauge only, It reads what ever it wants to. I read a couple of threads and followed this one and tore apart my dash. I took apart my cluster and inspected it and found no cracks or loose parts, no cold solder joints or nothing obviously wrong with it. I did notice that the motor for the fuel gauge was much stiffer that the others so I took it apart and found that there was a small broken gear in there. I decided to swap the back of the moter with the battery gauge since I need fuel gauge more. When I put it all together the fuel gauge was nice and loose and as you would expect the battery gauge was stiff.

When I put it back in the car I had a proper fuel level until the next time I started the car, then I noticed it was lower than before. so I restarted it a couple of times and each time it was lower and lower. Thats when I noticed that as I start the car the fuel gauge buries itself very hard in the empty direction then starts climbing back up. I think thats what broke the other motor. So I swapped the motors back so I didn't damage another motor.

So I am still without a fuel gauge, Does anyone have any ideas?

DADS05

Now I have another problem. I don't know if this is just coincidence or I caused it but after everything was put back together everything worked fine but the fuel gauge. When I got t into the car this evening the check engine light came on.

Did I cause that disassembling the gauges or is it just coincidence? Help!!

DADS05

bump Can some one help me

wyldv6

Try disconnecting your battery for 15 or so minutes, then reconnect. This resets everything and may clear the CE light. I've had the same issue and it works. Depending on your location the weather may be a huge factor. Had to let my car out of the garage for a few days and the cold whacked out my oil pressure gauge and speedo. Back in the garage on an even floor and everything is back to N O R M A L.

DADS05

Thank you very much! That corrected my CE light. Now if I could figure out my fuel gauge, I would be even happier. Do you think I am looking at having to replace my cluster?

05YellowGT

Sorry to give you the bad news , but my fuel gauge and occasionally my speedometer on my 05 stopped working and yes I had to replace the cluster. The good news is you can put a GT500 cluster in for the same price as a GT cluster. That's what I did and I love it ...

DADS05

Where can I get the new cluster and for how much? I tried searching online and could not find it.

05YellowGT

You should have looked in the interior section here , the link has all the info in my post #40 ...

https://themustangsource.com/showthread.php?t=477780

DADS05

Thanks.

V8Turbo

This is pretty common on the 2005 Mustangs, it's caused by failing stepper motors in the instrument cluster, they control the movement of the gauges. There's a guide on how to fix them here - 2005 Mustang speedometer problem

-Turbo

cme82

Yep. From what I read the 05's, and maybe not all but some, have bad stepper motors in instrument cluster and all are bound to go bad at some point. Not sure when the upgraded the motors to the newer kinds. However if one goes bad they all will eventually. And yeah apparently there are a lot of GM vehicles with the exact same problem.

I found a link on how to fix it yourself. You can find the motors on ebay fairly inexpensively, but it does require soldering on a pcb. So not the easiest of fixes. There are also some people on ebay that will fix it for about $60. I may go that route. Anywho here is the link on how to do it yourself.

I learned all this as my volt meter was pointing at about 8 o'clock all the time lately but the charging system is fine. Then yesterday my speedo was pointing almost straight down. Decided I better figure out what is going on.

DADS05

Thanks Guys, I'm going to try this. It will difinetly save me alot of money if it works.