MSD tach adapter help needed!

[frankenstang 11]

Good morning everyone,

 

Need some help for a friend of mine. He has a '67 Convertible with a clean worked 302. Car has a factory tach. Last week he installed an MSD 6al ignition box, MSD Billet distributor and matching MSD blaster coil. All was wired up and everything was working with the exception of an erratic tachometer reading. I recall when I did the MSD setup on my '89 I needed a tach adapter.

 

He purchased one last night and the instructions seemed basic enough but couldn't get it to work. Basically the white wire from the adapter went to the white tach feed out of the 6al, the black wire from the adapter went to a chassis ground, violet wire was not used and I thought the remaining red wire from the adapter went to the tachometer lead. When we connected it there was no tach at all. We then plugged the tach lead back into port on the 6al box and the tach was reading a signal but all erratic again. I'm lost.

 

Here is what wire we are dealing with:

 

Tach adapter:

Red (to tach)

White (to tach feed on MSD box)

Back (to ground)

Violet (unused as per instructions)

 

Coil:

Black (to MSD box as per instructions)

Yellow (to MSD box as per instructions)

 

MSD 6al box:

Red (to constant powers)

Small red (to keyed power)

Purple & green into a clip (to matching clip on distributor)

White (to tach adapter white)

Black & yellow (to coil)

Input opening (wire from tach into it)

 

Any help? Can't seem to figure this one out.

 

As always,

 

Thanks

 

Steve

[Alan_Mac 48]

From my experience, sometimes Tach Adapters don't work. Another very good option is to send the tach to Redline and have them install modern VDO internals. They will send the original internals back if requested. I did this and my tach looks stock and works fantastic. Can't beat the 1 wire hookup to the MSD,(in my case Crane Fireball).

[frankenstang 11]

How was the cost at Redline?

[Alan_Mac 48]

It was $200 with a 2 year warranty. Another nice thing about this conversion is the needle is on the zero when off.