Speedometer Randomly Cuts Out
05-05-2015, 02:44 PM
#1
Rennlist Member
Thread Starter
Speedometer Randomly Cuts Out
Originally the speedometer and odometer on my 85.2 944 were not working. I traced the cause to a burned resistor on the speedometer's breadboard and found that the odometer gear was bad. I ordered the Armworx speedometer rebuilt kit and a new odometer gear and rebuilt the speedometer. It worked great for about 500 miles and then the speedometer and odometer would randomly not work. They would cut out five or so minutes into my drive and a tap on the dash would sometimes bring them back and sometimes not. Sometimes I would just have to wait and they would come back on their own. Now that the weather is warmer, they do not work at all initially and after a few minutes of driving they will randomly come back after a tap on the dash. Can anyone point me in the right direction on this or has anyone else experienced the same issues and found a cause?
05-06-2015, 06:29 PM
#2
Drifting
Originally the speedometer and odometer on my 85.2 944 were not working. I traced the cause to a burned resistor on the speedometer's breadboard and found that the odometer gear was bad. I ordered the Armworx speedometer rebuilt kit and a new odometer gear and rebuilt the speedometer. It worked great for about 500 miles and then the speedometer and odometer would randomly not work. They would cut out five or so minutes into my drive and a tap on the dash would sometimes bring them back and sometimes not. Sometimes I would just have to wait and they would come back on their own. Now that the weather is warmer, they do not work at all initially and after a few minutes of driving they will randomly come back after a tap on the dash. Can anyone point me in the right direction on this or has anyone else experienced the same issues and found a cause?
05-07-2015, 08:30 AM
#3
Rennlist Member
Thread Starter
I pulled the cluster and checked the connectors. Zero corrosion. But I cleaned them anyways and I cleaned the connections on the breadboard. I cleaned the speedometer itself again and I made sure everything was tight upon reinstall. I then cleaned the connector for the speed sensor on the trans as a precaution. It seems to work fine as of now but that could be subject to change.
05-07-2015, 12:07 PM
#4
I have an '83, so might not be the same, but on the early cars the shaft the gear sits on is too long. Over time the gear can work itself loose or, as I experienced, the shaft has some free play. It moves back and forth, engaging and disengaging the gear. This happened to me with a new gear, usually when warmed up. I assume whatever lubricant is on the shaft became less viscous with heat and allowed the shaft move easier.
05-07-2015, 12:08 PM
#5
I have an '83, so might not be the same, but on the early cars the shaft the gear sits on is too long. Over time the gear can work itself loose or, as I experienced, the shaft has some free play. It moves back and forth, engaging and disengaging the gear. This happened to me with a new gear, usually when warmed up. I assume whatever lubricant is on the shaft became less viscous with heat and allowed the shaft move easier.
05-07-2015, 06:08 PM
#6
Rennlist Member
Thread Starter
Well so far so good. Took the car for a drive into town today and the speedometer did not cut out once. Hoping its fixed once and for all lol.