? about wiring to tach on 1988 115 yamaha

[boomhauer1032]

I recently pulled all of the witing off of the old breaker panel to rewire only the necessities. I installed a nice blue sea fuse block throughwhich I ran the electronics, nav lights, and bilge pumps. After cleaning the swith panel of the old stuff, I ran the pumps and nav lights through the switch panel. Everything looks and works great, except that I lost power and backlighting to the tach. There is a 3 wire harness (black,pink,grey) that came off the old panel which plugs into a harness with 4 wires exiting (purple, pink, grey, black). The grey wire entering is the power to the backlighting as the lamps come on if i jump power to it from the fuse block. It must be grounded, but im not sure where. The exiting purple butts to a yellow daisy chain running to all the instruments, but goes through the ignition i think before going to the tach. The black exiting butts to a blue daisy chain also running to the instruments. the pink and grey exiting both run separately to the gas gauge. I tried to jump power to the entering black and pink, but the tack wouldnt come on. On checking resistance, the grey entering was a complete circuit using the block for ground, but the pink and balck were not, even with the key in on position. The tach worked fine before I pulled everything, but not sure how to power it up again. Boat runs fine without it, but Id kind of like to have it.
Any help appreciated.
Mark

[Don S]

What tach do you have?

[99yam40]

http://www.maxrules.com/fixyamahawiring.html

See if this helps any

[boomhauer1032]

What tach do you have?

digital with trim level and oil level. The oil injection has been removed. Only need the actual tach.

[boomhauer1032]

Digital Tach with trim level and oil level. The oil injection is removed so all i need is the actual tach. Thanks

[99yam40]

Make and model is what he was looking for is my thoughts

did you look at the wire color chart?

[boomhauer1032]

Make and model is what he was looking for is my thoughts

did you look at the wire color chart?

I did. unfortunately some don't match. The black entering the plug/harness should be ground, but the backlights power up when I jump the grey wire to the positive block. I guess that means it is grounded somewhere. Do the instuments require one ground and one power (covering the instrument and backlight power both)? Or do the backlights and instruments require separate power? I know there is separate power on the tach as the instrument power runs though the key and the backlight doesn't.
All instruments have two "daisy chains" running between them. One blue, on yellow. No problem finding the backlight power, but can't find tach power.

[99yam40]

All the ones I have seen on Yamahas
blue = back light,
yellow = key on power,
black = ground