VDO Tach not working

[AFT1973]

Hi Fbbo folks.

My 73 RR 400 auto has a VDO tach installed. It has power, but doesn’t register anything. I’ve searched on line, but have not found info on where to start troubleshooting it. Any suggestions??

 

[70chall440]

Its most likely going to be the circuit board internal to the tach, I'd look for a replacement.

 

[AFT1973]

Its most likely going to be the circuit board internal to the tach, I'd look for a replacement.

Noted. Will keep that in mind

 

[70chall440]

That assuming that the tach is wired correctly as it is now. Look at the back of the tach, there should be 1 wire leading away from it to the firewall going into the engine compartment to the coil. If that is connected along with perhaps a 12V wire (not exactly sure how it is to be connected), it should function. If you have been under the hood recently and now it doesn't work, could be you pulled the coil input wire.

 

[AFT1973]

That assuming that the tach is wired correctly as it is now. Look at the back of the tach, there should be 1 wire leading away from it to the firewall going into the engine compartment to the coil. If that is connected along with perhaps a 12V wire (not exactly sure how it is to be connected), it should function. If you have been under the hood recently and now it doesn't work, could be you pulled the coil input wire.

Will check it out. Car has been in family since eatly 2000’s. I took it over after brother in law passed a few years ago. As far as i know it hasn’t worked for at least 10 years.

 

[70chall440]

Well I would probably just replace it unless there is some emotional tie to it. You can buy a pretty decent tach for under $150 these days brand new.

 

[F4R/T]

Get a good Stewart Warner ... I still think they are the best and not China made either, Mexican and some US.. Summit has the best prices on them.

 

[AFT1973]

Get a good Stewart Warner ... I still think they are the best and not China made either, Mexican and some US.. Summit has the best prices on them.

No emotional tie to it. Its just a tach. Thanks for the recommendations. If some easy tinkering doesn’t work. Thats the plan. Now if i can find a model # for this one, maybe i can find a schematic