Electrical Instrument Cluster Failure

[Nick3156]

Hello,
I have a 1994 mustang gt with major speedometer and odometer problems. Neither the speedometer or the odometer has worked for a while. I pulled the instrunent cluster to check the worm gears many have suggested and found then in tact. I did however find a burnt wire on the back of the instrument panel that led to "battery" right behind the speedometer. I jumped the broken section of this wire and plugged it right back in the car and thought i fixed my problem until the unit immediately started to smoke.... Any ideas on what else i could try? (Fuses are still fine)

 

[Nick3156]

I am almost certain that this would be the reason my speedometer and odometer are not working... but when i bridge the burnt wire leading to "BATT", smoke comes out of the dash

 

[90sickfox]

Something somewhere is shorting out along that circuit. What does that line lead to ?

 

[Nick3156]

The burnt wire on one end leads to the grey connector on the wiring harness while the other end goes to one of the three pins on the back of the speedometer.

 

[90sickfox]

Check the bulb at the other end of the line...the gray thing twists and pops out. If the bulb is good its probably your stepper motor. Hope this will help. They are the same from 94- 98

 

[Nick3156]

Check the bulb at the other end of the line...the gray thing twists and pops out. If the bulb is good its probably your stepper motor. Hope this will help. They are the same from 94- 98

Thank You so much for that testing procedure! None of the bulbs in the instrument are burnt out including the larger and smaller bulbs. I will test the speedometer in the way described in the document and post my results.

 

[Nick3156]

I have looked all through my transformer collection and i can not seem to find any 9-12V AC adaptors... although i can find plenty of DC adaptors. Any other ideas on how i can get 12v AC?Assuming that the motor behind the speedometer is the source of the problem, I have searched online for "1994 mustang stepper motors" ("-instrument panel","-intrument cluster repair","-intrument guage repair", etc...). Do you know where i can locate the motors i need to replace?

UPDATE: I decided to go to the scrap yard and buy a mustang 1995 instrument cluster. The problem with the unit was something on the speedometer computer or motor. regardless when i switched out the tachometer and speedometer unit of the instrument cluster everything worked fine, after minor calibration