Speedo problem

[Gary Davis]

1991 D150 2 wheel drive, 318 and 4 speed automatic. the speedometer hand will go to 100 or to the peg when barely moving. when this happens the odometer is flying as well. not a fast driver but super annoying to see the miles run up evry few second as this is a cherry truck with only 75,000 actual miles on it. any ideas to correct this would be helpful, thanks in advance

 

[65 sporty]

I believe the issue is in the speedo head, it still uses a speedo cable doesn't it?

 

[Gary Davis]

not this one, its electric

 

[7mopar]

Is this truck still all original?

 

[Gary Davis]

it is indeed, all but some of the paint

 

[7mopar]

Not sure what would be causing the odometer to read fast. It's all gear driven. Unlike the speedometer that operates more or less off centrifugal force. This is assuming it is still all cable drive and not an electrical drive unit.
It's not that hard to take out and take apart.
I would find a speedometer shop and have them look at it.

 

[Gary Davis]

as stated above, this is an electronic unit. first thing I did was replace the speed sensor on the tranny to no avail. researching other forums and you tube for possibilities.

 

[captainchrysler]

The speedo head is a common problem for the last few years of that body style. As popular as they are getting now I'd be surprised if there isn't a place making replacements or rebuilding them.