I've checked FAQs and can't find anything on installing and aftermarket tach in the dash. So, I've got this cool old SUN tach, very close to large tach size.

All I've got to do is connect the trigger, the positive and ground to the correct pins, and it should work, no?

I can skip the internal light as the dash light will illume the face?

I'm tired of the bouncy Volvo tach. If the SUN bounces I'm putting the clock back in!

If you want to light the tach face it shouldn't be too difficult - splice in a wire from the dimmer rheostat switch connector, and it would dim with the rest of the panel.

Does your cool old Sun tach have a switch that selects 4,6,8 cylinders?If it doesn't it's probably for a V8.


Dan

Yes, it switches 4-6-8, it's a Sun super tach II that I bought about thiry years ago, had it mounted in a '68 142S, threw it in a drawer until this week when I got the idea for a project.

I'm taking it out of the plastic housing, making a plasic mounting plate for the back of the instrument cluster.

I think all that needs connecting is the trigger, a 12v, and a ground, all of which are back there already. I can pull the + and - off the posts that the clock uses, and the trigger is white and red.

Guess the worst that can happen is that it may get fried, but if it works I may never have to watch the ubiquitous freakish maddening bouncing needle again.

If I understand you correctly you are going to re-use the back of the old tach (including electrical contacts to the cluster) to mount your new one? Then you should be able to get +12v for the tach and ground from the 3 prong connector for the small 52 mm clock on the back of the tach. The white/red wire is the signal from the coil.
Dan

Yes, i'm cutting out, using the clock back as a pattern, plastic to match. All screw holes will line up, and simply using the SUN's existing mounting screws to the back of my new plastic cover!

Powered up from the existing + and - poles, and triggered with the red/white wire, lighted from above with existing dash lighting, should work like a wet dream. Using a scroll saw and eighth inch lucite plastic to glue up a sandwich of necessary thickness.

A fun project at 15 below on the kitchen table using an extra instrument cluster to practice on. Why is it so cheap to have fun?

OK you are using the old clock, not the tach. Should work fine.
Dan

All you connect is the red and white wire that comes from the + pole of the coil. That's it.
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1985 244DL B230 M46 170k

I had to go look...and I'll be damned, you're right.

In any case, the red/white wire should be spliced into the spade connector on the coil already, so just find the other end of it loose behind the instrument panel. On my car, it was bundled with the main harness to the inst. panel.

Charlie
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1985 244DL B230 M46 170k