83ttopgt

I have an 88 gt. With a carbed motor. I found the green/yellow wire under the hood and hooked it up to the (-) side of the coil. Tach bounces when starting the car, and twitches when the key is cycled. But it doesn't work.

The car has an msd box/ coil/ distributor etc.

With that wire (green/yellow) wire not connected to anything, the tach still twitches upon cycling the key.

I also tried hooking up the factory temp sensor wire, nothing there either. Both on a sender and direct to ground. Nothing

I am thinking that maybe my cluster does not have power. But the gas gauge appears to work. and the oil pressure gauge moves with engine speed.

Am I missing something obvious?

Thanks guys

mjr46

yup, if you are using an msd box, you need a tach adapter to make the oem tach work, or use an aftermarket tach and hook into the tac feed from msd box, I use a tach adapter from msd on my 85 with a 6al to get the oem tach to work

tohoopty

i run a wire to the back of the cluster for all 3 carb'd mustangs i have been a part of

projectresto83

I just spliced the wire going to the stock gauge into the signal wire for my autometer tach.

83ttopgt

and you are running an MSD box?


Also any idea why the temp guage isn't working even if I direct ground the wire for the sensor?

projectresto83

I was running a MSD blaster box. I don't have a carb setup anymore. I just switched to EFI.

83ttopgt

?????

mjr46

try a new sending unit first

tohoopty

i just did this to my dads car and hes got a msd box.seems to work fine

83ttopgt

I have an aftermarket gauge that works fine off that sending unit. I also went direct to ground with the wire and nothing at the gauge