Tachometer Sender

[Stagger]

hi,

my tachometer doesn't work. i have an 66 barracuda formula s. the wireing under the dash is original.
my sending unit is also original. i bought the car some months ago. the preowner has installed a customized dash with autometer instrument. now i converted the dash to stock but the tachometer doesn't work. i measure on the sender that on the yellow cabel that goes to the tachomter had only 0.4V. if i turn the engien higher it stills stay by 0.4V. the voltage should go up.
i think that something wrong with the sender. i will try to put 1V - 4V directly to the tachometer to look if its work. i a right?

were can i find a circuit diagram of the stock sender? so i can check the electronic.
the preowner has build in a 360 engine with the orange mopar ecu. does the old sender work with this electronic ignition?

i know the RT-eng reproduction board...and maybe will be buying them. but want to know why it doesn't work.

thanks

 

[67Dart273]

Found this

http://www.forabodiesonly.com/mopar/showthread.php?t=247360

You won't find a diagram of the internals of the sender if that's what you are thinking. This should work with a Mopar ECU

Frankly, I would just replace the sender with an aftermarket board. Take your ohmeter and start at a high "scale" Put your ohmeter directly across the tach meter and make sure it moves and seems to not be sticky, IE the meter movement bearings are OK. If you don't get much deflection, click your multimeter "down" towards lower ohms scales and try again.

The meter "head" ground should be a separate wire run clear back to the sender ground terminal. Do not ground the meter on the car body haphazardly.

 

[Stagger]

hi,

yes i was looking on a diagram of the internals of the sender. want to check what wrong with it. does everybody buy a modern one, nobody try to repair?

when i connect my neg of ignition coil (it's an MSD Coil) to the grey (M) cabel that goes to the tach sender the engine shut down.