1976 Evinrude 135, Tachometer wiring/help

[ocb_dave_ocb]

1st off, I have searched for about an hour now, about Tachs, wiring, adaptors and all.. This is what I have.

1976 Evinrude 135hp/1970 Switzercraft. Has a tach included (doesn't work) So today I pulled the tach out, it has only 2 wires, and a rotary dial. The wires are Yellow/Black. They are just hanging there. So essentially I have NO TACH..

I am wanting to install a New tach, I have been looking at some on ebay. The problem is how am I supposed to wire this sucker.. I have seen were some people have purchased adaptors to plug into the RC. I looked and I didn't see anywhere an adaptor would connect..

So Im going to go with option two, UNLESS someone can tell me where to find this "adaptor plug." I know Im going to hook the black wire to a common ground, I know the positive wire needs to go to the ignition wire, how do I go about connecting this? Just remove the igintion from the RC and connect the wire?

Next onto the signal/pulse, I see on the net were my rectifier is supposed to have 4 wires? yellow, Yellow-Gray, Gray, and one more not sure of color.. On the interenet I have found my rectifier P/N 18-5708 this rectifier has 3 wires, 2 yellow and 1 red. Do I need to connect the pulse to one of those yellow wires.

Any info would be greatly appreciated guys, this is a great site and I want to thank you all in advance.

 

[Silvertip]

Re: 1976 Evinrude 135, Tachometer wiring/help

A new tach actually has four connectons. 1) Ground, 2) +12V when key is on, 3) internal light, and 4) pulse or send. Any of the other gauges except the speedometer has a +12V and ground connection on it. Connect ground and +12V to any gauge. All of the other instruments have a light terminal. Connect the light terminal to any one of those. The pulse or send line connectes to one of the yellow wires on the rectifier. you don't have a place on your controller to connect to so follow the wires you now have for the tach back to the engine. Use which ever one connects to the yellow wire. See how easy that is.

 

[ocb_dave_ocb]

Re: 1976 Evinrude 135, Tachometer wiring/help

The only gauges I have are Speedo and Tach.. So I suppose im back to step one.. I wired up a tach in my show truck, so im sure I can do this.. Just trying to find the correct points.

HOT WIRE - Ignition Switch - Do I need to hook it directly to the ignition (i.e. remove iginition switch from RC and direct solder it?)

GROUND WIRE - Common ground or negative on battery

ILLUMINATION WIRE - Leave disconnected or wire to other light source

PULSE WIRE - I do need to hook this up to the yellow wire on the rectifier CORRECT?

Thanks again guys

 

[ocb_dave_ocb]

Re: 1976 Evinrude 135, Tachometer wiring/help

After looking at the motor I would like to know if I can use these area to hook up the "gray" wire

Its says

RED , YELLOW, YELLOW-GRAY, GRAY, YELLOW, EMPTY, PURPLE, EMPTY

Something like that.. Can I just put a the gray wire to the screw that says GRAY on it?

Next were should I do the positive wire? To the ignition switch or where?

 

[Silvertip]

Re: 1976 Evinrude 135, Tachometer wiring/help

Picture is too fuzzy to tell. +12V must be connected to whatever wire you can find that is hot when the key is in the run position. If that means you need to get to the ignition switch, then yes. Ground is ground -- wherever you can find it. Pulse line again is back at the engine but can't tell from your picture. Where does the existing tach wire end up at?

 

[ocb_dave_ocb]

Re: 1976 Evinrude 135, Tachometer wiring/help

Picture is too fuzzy to tell. +12V must be connected to whatever wire you can find that is hot when the key is in the run position. If that means you need to get to the ignition switch, then yes. Ground is ground -- wherever you can find it. Pulse line again is back at the engine but can't tell from your picture. Where does the existing tach wire end up at?

There was one, it was just two wires on the tach itself.. Like someone had just set it in there for looks..

My camera seems to suck sometimes.. That pic is at the engine right beside the flywheel.. Im not sure what that peice is called..

 

[ocb_dave_ocb]

Re: 1976 Evinrude 135, Tachometer wiring/help

That picture is of the terminal block. Now can I hook the signal wire to the "GRAY", "YELLOW-GRAY" screw on that terminal block?

I guess this point will work.. It is were the Rectifier actually connects to the terminal block.. Will that be an ok Point for the Signal?

now lets talk hot wires? What are my options as far as it goes besides the igntion?
Postive to battery with toggle in the middle?