No speed/no tach 99

[strick]

My '99 tach and speedo have been off an on for years. All other guages are reading normal. Something has bound to have come loose intermittent ground or signal wire that only controls the 2? Sometimes one will come on and not the other. Frustrating! My '98 12v does the same thing. What would be common between the 2 engines? If it's a grounding, then point me where under the dash or etc. Thanks, strick.

 

[2ndgenBo]

Unlikely to be your problem but in case anyone else has this issue...my tach always works fine but intermittently my speedo will not work. I realized by giving a "love tap" to the front of the gauge cluster that it miraculously "fixes" the issue...at least for a few drives. Must be a sticky needle.

 

[Joe Mc]

If I'm remembering correctly, on my 99, same thing was happening probably more than 10 years back. Although it didn't make sense someone suggested cleaning the rear axle abs sensor. Doesn't take but a few minutes and if it doesn't work nothing lost.

 

[Ozymandias]

Unlikely to be your problem but in case anyone else has this issue...my tach always works fine but intermittently my speedo will not work. I realized by giving a "love tap" to the front of the gauge cluster that it miraculously "fixes" the issue...at least for a few drives. Must be a sticky needle.

More likely a cold solder point.

 

[strick]

More likely a cold solder point.

More likely a cold solder point.

The love tap worked for yrs, but it's time for a John Henry hammer now!

 

[Topzide]

Start with any grounds under the hood, these are the first points of contact for the current to flow. Then look for any that attach to the firewall on studs/bolts as these help carry into the cab. Even if they look clean, loosen them up and clean. After cleaning them, a shot of Fluid Film on the will help keep corrosion at bay. There's a big reason that they use Aluminum Ox on aluminum wire in buildings. The corrosion that forms will decrease the amount of voltage and current, which creates heat! Seems that a cold solder/broken joint could be at fault also. Easier to check and clean grounds before having to pull speedo head. Clean grounds help with other functions of the truck.