Tachometer not working on 240z???

[1sick72z]

i have a 1972 240z i'm not sure why it's not working but does anyone have a diagram or picture of where the wires go from the back of the tachometer? i checked but no luck... doesn't the tach wire goes to the distributor if i'm not mistaken?

[EScanlon]

Post number 5 in this link has a wiring diagram that will help you.

http://www.classiczcars.com/forums/showthread.php?t=27896

But as long as the tach is connected to the wiring harness in the dash AND you haven't disconnected the wiring at the coil, the car should start.

You don't mention whether the car starts but the tach doesn't work, or that the car doesn't start. If the first, check the wiring at the coil and the ballast resistor.

FWIW

E

[1sick72z]

Post number 5 in this link has a wiring diagram that will help you.

http://www.classiczcars.com/forums/showthread.php?t=27896

But as long as the tach is connected to the wiring harness in the dash AND you haven't disconnected the wiring at the coil, the car should start.

You don't mention whether the car starts but the tach doesn't work, or that the car doesn't start. If the first, check the wiring at the coil and the ballast resistor.

FWIW

E

it has msd ignition now and the wire seemed hacked... it starts but can't seem why the tach won't work..

[EScanlon]

Ahh...an MSD.

That has it's own issues, do a search here using MSD Blaster and you'll find a couple of posts on it.

E

[1sick72z]

o.k...now i read that i have to buy a tach adapter in order for it to work with a 240z tach... i have a question, can i just use like an older model tach so i don't have to buy a tach adapter? and if i do buy the adapter how do i hook it up... the white wire on my msd is not hooked up to anything?

[EScanlon]

Not sure what you would have to do.

It isn't because of the model of the tach, your 72 IS the "older" style, i.e. the "loop" or 4 wire tach. Rather it's because of the MSD. Check out the other posts regarding what they did. Myself I use a 280ZX E12-80 dizzy with my original 71 tach and it works fine.

Sorry can't give you more help.

E

[Six_Shooter]

Here's a couple links:

http://www.zhome.com/ZCMnL/tech/cooper.htm

http://www.zhome.com/ZCMnL/tech/ThomasMSD.htm

I haven't verified if the diagram in teh second link will work or not, but that information is there.

It's from www.zhome.com

[1sick72z]

what year and model chrysler have dual ballaster resister?

[Curtis240Z]

You need this MSD tach adapter:

http://www.msdignition.com/pdf/8920_frm22049.pdf

[1sick72z]

You need this MSD tach adapter:

http://www.msdignition.com/pdf/8920_frm22049.pdf

yeah... that's what i thought but i couldn't find it on msdignition.com and i was researching and one of the threads said a different part number...