C3 Corvette Mechanical to Electronic Tach | On the Mark with Mark

Replacing the Distributor Driven Tachometer in a Corvette with an Electronic Tachometer from a later Model Corvette.
Corvette Tachometer Upgrade.

[@wilbranka]

Just the info I needed to do the same job, Thanks!

[@wilbranka]

The only thing I would add, is that I had to grind off some of the contacts from the meter assembly that would have made contact with the modified bracket from the 68/69 tachometer once fitted into position. Good info, saved me from having to reinvent the wheel.

[@OntheMarkwithMark]

Yes, I did the same. I don’t think I covered that as good as I should have.

[@wilbranka]

@@OntheMarkwithMark I thought it was great...kept me from having to reinvent the wheel.

[@cliffords8869]

Hi Mark. I had a shop install the electronic tach conversion kit. However, when the ignition is off, the needle spins slowly counter clockwise and stops at 4500 on the dial. They didn't have any reasonable explanation except, "when the car is running the RPM is accurate". In trying to resolve the issue, I connected a feed wire from the reverse switch (neutral safety switch) to get 100% off until switch is on, however, it didn't change the needle behavior. I noticed in your video you didn't address the needle's position when the power is off, I expect it to be at zero. Also, I noticed you made a distinction between a mechanical needle and the electronic needle (having a counter weight). Is that a factor to consider when trying to get the needle to zero when power is on or power is off?? Just wondering if there is a solution or if everyone else is experiencing the same thing and have to live with it. Thank you.

[@OntheMarkwithMark]

Hi Clifford, all the factory electric tachs jump up to 1200rpm or so when the power is off. This is considered normal. Your issue, I have never seen nor heard of before.

[@cliffords8869]

@@OntheMarkwithMark Are you saying all factory installed electronic tach needle points to a number on the dial other than zero when the power is off?? I've had a few newer cars and the needle always rest on zero when the power is for. Thanks anyway.

[@OntheMarkwithMark]

@@cliffords8869 that’s what I’m saying.

[@harrywood8196]

I am about to do this also. Putting in a 1975 electronic tack in my 69. That has green #'s. Same problem being screw holes are different, wish me luck, thx.