Newer style tach board on 66 Charger

[dbowperson]

Hi guys. I'm looking for some help, here. I have been getting some work done on my brother-in-law's 66 Charger, and recently had the gauges rebuilt. The sardine can tach sending unit was fried, so the guy put in what I guess is a later style tach board so the wire could be run straight from the negative coil to the tach. The car has been converted to a standard orange box ECU with a Blaster 2 coil, so the pints are gone. The problem I am having is the tach is acting very weird. It seems to work fine for the first few minutes at idle, but once we start driving, the needle just starts flipping all over the place like the signal is screwed up. I've swapped out the coil for a standard MP coil, and even hooked the tach up to a different car to make sure it is good. I have been told I need an MSD or Autometer converter wired in to make it work right. Does this make sense, and if so, where does it get wired in?

 

[chignikred]

tach

i dont have an answer but I can point you to some one. Your board may have come from here, but the installation wasnt engineered correct, taking into account all factors.

http://rt-eng.com/mediawiki/index.php/Main_Page

Consult with them, it may cost, but money worth spending to get it right.

red

 

[dbowperson]

It did not come from RT, but I have used them in the past for our other car, so I'll give them a shout.

What do you mean by the installation wasn't correct? Are you referring to the tach board itself, or something to do with the ignition? I did pull the tach out and hooked it up to our Challenger and took it for a drive, and other than reading a little high, it worked just like I would expect it to with smooth motion and quick response. Unfortunately I'm much more familiar with the 69 and up stuff, so this kind of has me stumped.

Something I forgot to mention is that all the other gauges work fine.