'99 Volvo VNL Speedometer Issue

Is it just the speedometer not working, or tachometer as well?

As I understand tach works off flywheel sensor ( on bell housing), and speedo off the tail shaft sensor on gearbox.

Did you check resistance of sensor, and check same resistance to wires in back of speedometer cluster (continuity of signal/ broken wire is where I’m going with this) ?

 

Try it and see. Worst case is running a jumper set of wires to dash to test.

I understand those clusters are expensive.

Rely on GPS or scan guage speed for now?

 

Check your speed sensor install setting - I know the tach required ‘screw all the way in, then 1.5 turns back, set lock nut ‘

Just in case it’s too far away.

 

The cruise can be upset by other things - faulty clutch pedal switch, TPS, etc.

If it sets at idle and raises RPM, I’d suspect clutch or brake switch - both will disengage cruise.

Wait - no - isn’t there a park brake switch involved too?

 

I’m no mechanic by the way, just had similar issues in an older truck with 12.7 and N-14.

Make sure you post your resolution on here to help others, that’s how this forum works.