VDO Tachometer Reading 900 RPM
- Thread starter swifty
- Start date
Seastoke
Well-Known Member
Is there not an adjuster on the back to zero, or disconnect wire in case you have a stray voltage.
oldgit
Well-Known Member
Check earthing/volts.
Doubt any "adjustment" that going to zero that needle
Disconnect completely and check if needle goes back to zero.
If not.....
The really keen could attempt to dismantle and perhaps check inside tacho . Might be simple case of undoing a couple of nuts
or even gently uncrimping that crome bezel.
It is highly likely this may not cure the problem and a replacement may be required.
If you do need to replace unit genuine "VDO" unit might be eyewatering, however here are several units out there, with hours meters, will do the job ensure that it is a 4000rpm device and make sure it functions with your sender unit, might be from your alternator or dedicated sensor somewhere. ie flywheel housing.
Recently one of my flybridge tachos played up, dismantled once or twice, then bit the bullet and replaced.
Changed both fly tachos so they matched but "budget" replacement units only function from alternators, so had to run two new wires.
Doubt any "adjustment" that going to zero that needle
Disconnect completely and check if needle goes back to zero.
If not.....
The really keen could attempt to dismantle and perhaps check inside tacho . Might be simple case of undoing a couple of nuts
or even gently uncrimping that crome bezel.It is highly likely this may not cure the problem and a replacement may be required.
If you do need to replace unit genuine "VDO" unit might be eyewatering, however here are several units out there, with hours meters, will do the job ensure that it is a 4000rpm device and make sure it functions with your sender unit, might be from your alternator or dedicated sensor somewhere. ie flywheel housing.
Recently one of my flybridge tachos played up, dismantled once or twice, then bit the bullet and replaced.
Changed both fly tachos so they matched but "budget" replacement units only function from alternators, so had to run two new wires.
PaulRainbow
Well-Known Member
I fitted KUS tachos to my lower helm, they run from the sensors or alternators.
Plum
Well-Known Member
That happens to mine (different model VDO) it stays at the idle speed when I turn engine off. It's normal. It only resets to zero the next time I turn the key to the first notch before starting.
