Bosch Retro tach not reading correctly

[6t4polara]

Friend just installed a new Bosch retro tachometer and it reads 4,000 at idle.
The car is a RB block with a new Mopar electronic ignition.
He has the wires connected correctly ,and the switch set to 8 cylinders. Any Help would be appreciated.

Thanks,

 

[khryslerkid]

Sounds like something isn't wired correctly. Or maybe not a good ground if it uses one.

 

[Demonic]

Google up that model and see if it works with Mopar electronic ignition. Move the switch back to 6 or 4 then back to 8 to make sure the contacts are fully seated.

 

[khryslerkid]

I installed one on my '62 but it is a points system. Instructions don't really mention the Mopar electronic ign. just the newer ecu style. See if you can decipher anything out of them.

PDF Download...
https://www.boschperformance.com/sites/default/files/0002-000-3113.pdf