Isuzu Repair: 1991 Isuzu Rodeo Speedometer, speedometer cable, isuzu rodeo

Question
QUESTION: I purchased our rodeo a year ago. The speedometer has never worked. Where should I start looking? Are there any recurring speedometer problems on this vehicle?

Also, thanks for the advise on the heater core. The repair cost $150 and our mechanic had it done the same day.

ANSWER: Hello Jeff. Thank god I was wrong on the price huh?? I am so glad it worked out for you. As for the speedo problem. They run off of a cable that connects to the transmission. Their is a plastic gear inside that is probably stripped. It happens all the time on these models. Also Check the back of your gauge for any stripped threads or it could just be unhooked! I have seen people unhook these to make it look like the vehicle has low miles, which is very dishonest and not to mention(ILLEGAL!) I will do some  research for you though and find an answer ok?

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QUESTION: Daniel, typo error on me, it wasn't $150 it was $250 to replace the heater core. You were right on the money! Thank you.
I have checked the speedometer cable yet. I'm in Michigan and don't have room in my garage...its 10 degrees outside.
Can I get at the back of the gauge without removing the dash?

Thanks again, Jeff

Answer
Well Jeff. You might be able to reach your hand up there and feel if it is connected or not. It is a black round cable. Although the dash issue might be a little tough. If you hear any whining or scratching coming from the transmission plug to the speedo plug. That means it is stripped and needs replacing.