Repro LED hood tach not showing true engine RPM's...

[318MoparGuy]

Hi All,
My repro LED (I didn't install it and PO has no paperwork on it) hood tach started acting up when my alternator went south on way home....the needle was bouncing back and forth like a ping pong ball until the battery ran out of juice.I replaced the alternator and voltage regulator and the system is charging properly now, but the hood tach is not giving a true reading of the engine RPM's...it barely moves off zero when idling...before it sat at 800 RPM's at idle. Does anyone recognize this model/brand (see photo) and can it be reprogrammed or be reset to make it functional again? Thanks in advance for any and all help.
Greg

 

[fastnos]

Looks like a Dixco Hood Tach. Try doing a search for dixco hood tachs, and look for a site for " the tachman." He can answer all your questions, and do any repairs you might need. Good starting point, and there are a few other sites too. This should get you a little more info, and let you decide, what way you want to go with it. ( hope it helps )

 

[318MoparGuy]

Looks like a Dixco Hood Tach. Try doing a search for dixco hood tachs, and look for a site for " the tachman." He can answer all your questions, and do any repairs you might need. Good starting point, and there are a few other sites too. This should get you a little more info, and let you decide, what way you want to go with it. ( hope it helps )

I will contact him...Thank you for your help...Greg

 

[cudajim]

I would suspect an internal voltage regulator has gone bad or possible an internal resistor or both.