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Topic: Speedomter Broken (Read 1221 times) previous topic - next topic

Speedomter Broken

I got my car out a few weeks ago and tested it out on the highway and ended up breaking my speedometer needle although I don't exactly know how one does that.  The gauge on the '88 Sport Coupe will only show hashes up to 95 mph and the needle was bouncing around 96 for a bit before it ended up back at 0.  Since then I have driven a few hundred miles and of course only registering about 10 miles.  The speedometer needle will still from time to time bounce around but not consistently.  When it bounces is the only time it will measure miles driven.  All of the other gauges in the cluster work perfectly fine.  How do I fix the speedometer needle is my first question? My second is, while fixing my speedometer, can I also replace the cluster light?  I have been thinking about replacing the factory green bulb with a blue one.  Thank you for your support.

Speedomter Broken

Reply #1 –
Test the speed sensor before replacing the speedometer. It's bolted on a transmission. Use a AC voltmeter to test it, it should generate AC voltage (higher speed means higher voltage and frequency).

Speedomter Broken

Reply #2 –
speedo gear on the speed sensor is probably worn out.

about a 15min job to replace

Speedomter Broken

Reply #3 –
jrcassity, you were correct.  The speedo gear was half hanging out of the transmission.  I order a new one from RockAuto and will hopefully have it by the end of the week.  Thanks for the direction.

Speedomter Broken

Reply #4 –
I replaced the speed sensor and that fixed the speedometer for the most part.  When I sit idle the needle still fluctuates between 0 and say 8 mph.  It's enough to notice the mileage creep up on the odometer when sitting at a longer intersection.  When traveling the needle is controlled at least for the 5 or 6 miles I tested it with.  Any idea what would cause this to happen?

Speedomter Broken

Reply #6 –
That can't possibly be normal.  There's got to be a problem. You shouldn't have a speedo needle that jumps at a standstill. Any other oddities in your cluster maybe gauges that indicate high? Any connection issues? It's a long shot, but are you using spiral core pug wires, do you have radio interference? Anything weird at all that may or may not be related?
 

Speedomter Broken

Reply #7 –
I do have a fuse that needs to be replaced.  My radio, clock and whatever else is on that fuse is out.  I don't know why that would be related.  The rest of the gauges on the cluster are working fine although when I did brake aggressively after running the car pretty good the gas gauge went up to full and then back to 3/4 full.  Years ago the car was in a minor fender bender (it had been bounced off a guard rail and needed a right front and rear quarter panel replaced) and for a while after that, the cluster would act weird where the temperature, gas and oil pressure would all peak for a bit and then settle back in normal mode.  I haven't noticed any issues for a quite a while with the rest of the cluster however the speedo needle has been acting funny consistently since I swapped in the T5 about six months ago.