Speedo on a 4cyl TJ

[RidinRyan]

My brothers got a 97? TJ 4 banger and he siad when hes driving on the high way at a constant speed it will bounce from 40 to 60 to 100 and all around, sometimes settling at the right speed.  Any idears? Thanks

 

[JeepinMaxx]

I think the speedo on the '97 runs off a signal from the vehicle speed sensor (located on the T-Case).  I'd check that 1st, along with maybe a bad ground.

 

[Rubi04TJ]

actually it is a little plastic gear in the T-case, maybe the teeth are worn on it, they are cheap to replace at 20 dollars to, and not hard to do.

 

[kvjp97]

Funny.......Must have been a 97 thing. I was driving home tonight and it started to do the SAME exact thing. I'll be checking the speedo sensor tomorrow...

 

[tjcoastie20]

it sounds like a bad electrical connection to me by the erratic operation described. perhaps some chafing in the harnness creating a short?

 

[massxj]

check the connector at the back of the cluster.  i think there is a TSB on it.

 

[Rubi04TJ]

There is a TSB on the connector, but usually when that is loose the whole dash goes out at the same time.