Compatible tach with MSD Distributor?

[Junky]

I've tried two Autometer tachs (Auto Gage & Street Tach) with the MSD Ready-To-Run distributor. Neither works with the MSD distributor.

Anyone know which Autometer tachs work with the MSD Ready-To-Run distributor? How about the Autometer Sport Comp tach.

Ready-To-Run distributors do not need the multi spark box to work. It is self contained.

[pishta]

What are you hooking up the tach trigger to? If you are using the MSD tach out, it sometimes needs an amplifier. Try using the original tach out on the distributor or maybe the original box run in parallel. Running them in parallel allows you to change boxes if one goes bad with a switch. I think Autometer or SUN has a printout that shows what tach works with what boxes.

[Junky]

Thanks for your reply.

But...the MSD Ready-To-Run does not need a multi spark box to work. It is a self contained, Ready-To-Run distributor. Just like a stock distributor only alot better...no box! A multi spark box can be added if you want, but not necessary to run a Ready-To-Run MSD distributor. I installed the new distributor just like any other, connected three wires. One to the + on the coil, one to the - on the coil and the other is the ground. Neither the Auto Gage or Street Tach works when hooked up to the negative post on the coil.

[dwc43]

Call msd. Even though I know I run a msd 7 al2 box it does mention some tachs will have problems. THey have adapters and rf filters and amplifiers to solve this problem. They will know for sure so just call them.

[Junky]

I figured out the problem.

[dwc43]

Let us know in case we run into it the same problem ,please.

[Junky]

Here's what happened. Instructions to install the MSD distributor said to wire the hot red wire to the ignition switch wire, not to coil. I called and asked MSD if I could just connect the two distributor wires (red and orange) directly to the coil, just like the stock setup had been wired. They said that would be just fine. I wanted as little wiring as possible. Well, the engine and distributor liked it just fine, but the Autogage tach did not. I tried the Autometer Street Tach and it didn't work either, which many said would. I got to thinking...and took the hot red wire off the plus post on the coil and connected it to the high side of the ballast resistor, then hooked up the Street Tach. The tach worked!!! So, the tach doesn't like both distributor wires connected to the coil, even if there is 12 volts off the coil. Run the distributor hot red wire to some other 12 volt source that's only hot with the key on. The orange wire goes on the negative post to the coil. Black wire to the ground. Green wire off the tach to the negative post on the coil. End of story. Who wouldda thunk.

[dwc43]

No one caught this including me. The dist. never got 12 volts if you wired it off the coil due to the resistor up stream. Wonder it started an ran at all. Lucky it did not burn it up. Somebody at msd really goofed when they told you that.