joji

I recently had someone do a
coolant flush on my 05 mustang
and he also replaced the thermostat.

The next day I notice my temp gauge is not moving
ON or OFF and is stuck just a little pass the middle

Stang-aholic

Your not going to like the worst case scenario answer to your problem, but this isn't the first time I've seen this, and its becoming more common with time.

First to possibly solve this the easy way, disconnect your negative battery cable, leave disconnected for 15mins. Reconnect and check if that fixed it. Sometimes little electrical problems can cause stuff like this to happen.

Check ALL electrical connections that may have been disturbed during the thermostat install, this could be solved as easily as plugging in a small plug or hose that was forgotten. Also make sure all the wires in the area of the thermostat aren't binding/stretched/pinched in any awkward way .

Another little bit more indepth thing you can check is to take the gauges out, removing the plastic cover and see if the little needle is just jammed or sticking somehow.

If this doesn't solve it, and it continues to not move AT ALL, then the little electric motor behind the face plate of the gauge cluster has gone bad and needs to be replaced. This requires removing the entire gauge cluster, disassembling it down to the circuit board level, unsaughtering 4 saughters that hold the little plastic/electric motor to the circuit board, remove the defunct motor, resaughtering in the new replacement motor from Ford. A pain to do, but it doesn't cost that much if you can do it yourself. This would be the absolute last thing I would do. I have a video link on YouTube of someone doing this, but its saved on my computer not my iPad.

joji

thank you!

I am going to try this out.
although I am not so sure I can do the last option.

Stang-aholic

welcome, post up when you find the solution/problem haha

heres the video pt. 1 of 3

Nuke

If it's not a sensor issue, then you're the victim of a chronic problem with the gauge cluster stepper motors which was rampant in the 05's and early '06's.

kevinmalec

Yep, I am a victim of my stepper motors going out.

My thermostat gauge only works if it is 60 degrees or warmer outside. My RPM gauge is off by 150 RPM-250 RPM and my gas gauge is sometimes off by a 1/4 tank.......

Tbones80

Sucks, but can use it as an excuse to upgrade. The gt500 cluster is same price as the gt, but has mycolor in it (if you have the wiring harness behind where the buttons would be, you can use it) and looks a ton more modern. Im waiting for my stepper motors to go out!

joji

as of right now its gone beyong the H (hot) and pass it.
im guessing its a guage problem?

so how do I go about fixing this?
changing the motor for the guage?

I also notice my rpm guage doesn't work sometimes.

Stang-aholic

yes your going to have to order the motor from Ford. I do not know the part number. Then take apart the cluster and replace the bad motor. Follow the videos I posted, they are very informational

Tbones80

Can get em off ebay, probably alot cheaper then Ford. Search mustang stepper motor. If the soldering part intimidates ya, take the circuit board and new stepper motors to an electrician/tv repair man. They can replace them all in under an hour. May as well
replace them all while you got it apart.