Speedo works intermittently, VSS??

[rkreigh]

strange problem, most of the time when the car is cold, the speedometer doesn't work. I'll drive it for 10-15 min (sometimes a bit more). the speedo will start working again. sometimes the car sets a code (need to pull it). at low speeds the needle is a bit jumpy until I get up to 35 or so most of the time when working.

the scanmaster does show zero mph when the speedo is out.

a few questions, this sounds like it might be the VSS, is that the sensor with the weatherpack 4 wire plug on the drivers side of the trans? I also noticed a regular looking speedometer cable.

can't find my service manual right now, it's packed away somewhere after moving!

tia for any advice.

 

[TurboBuRick]

VSS is built into the speedo itself. Sounds to me like the problem is in the cluster.

 

[rkreigh]

thanks! very helpful advice, that sure makes sense.

good excuse for the GNX dash upgrade as my car is a "white GNX" with the body flares

 

[Slow91z]

My 1st guess is lube the cable.

 

[rkreigh]

I'll sure give that a try. let me do some searches and see if I can figure out the best way to get at the cable. sure wouldn't hurt

 

[turbofish38]

It's either the speedo cable or the speedo drive and driven gears inside the tranny. I'd check those out first before you install the GNX gauges.

 

[novaderrik]

mine used to do that- the speedo would read all jumpy or not work at all until the heater kicked out some heat when it was below about 40 degrees outside- but it fixed itself and hasn't done that for a few years now.

 

[rkreigh]

I'm thinking I have a bad connection or some corosion on the dash.

car has t tops and they leak a bit

I notice some moisture in the "tray gauges" sometimes

problem used to be very intermittent, now it happens whenever I drive it.

sometimes the speedo will work right away and quit, and other times not for 10-15 miles or so.

I'm going to pull the cable, but I'll need to research pulling the clutster out

how ez is it to get the cable out?? thanks!

 

[Roc87]

Speedo cable is two pieces, Connector is near the master cylinder. Bottom cable is easy to lube, but the upper cable needs to have the cluster pulled forward to get access to it IIRC. May also be speedometer itself. I lubed the cables on mine a couple years back, much better now, but still jumps a little and makes some noise when it's cold.