Harley offers a mini tach and bracket that works with the windshield. I use one on my Heritage Classic.

 

Have you got a part number for that?

 

Yea, good luck finding one... They don't make it any more... I have 2 and neither work. They have an adjustable potentiometer in them for calibrating that tend to lose connection.... If any one knows who can fix them, I'm listening...... That's why I purchased my Dakota digital Speedo with tach...

 

There's lots of them aftermarket from $30 up:
https://smile.amazon.com/s/?url=sear...rley+mini+tach

98, if you know what value the resistor is supposed to be set at, it wouldn't be too hard to hard wire one in place of the pot.

 

Thanx Doc, but the problem is getting the plastic casing apart to get to it..
The part number is P/N107612

 

I've taken bigger ones apart. It isn't easy. PITA, actually. Usually, there are a bunch of crimped over tabs. The really hard part is getting it back together.

 

I have one on my 1997 Softail with a stock Harley windshield.
The bracket is bent at about 30 degrees and is mounted to the two back handle bar screws. I needed to get longer screws and put a spacer between the back of the bracket and the handle bar clamp to space the bracket up to clear the top of the clamp.

 

After bending the mount up find an old windshield and cut out an opening for the tach and see how that looks.