OMC Throttle accessory wiring

[lazersnake]

Hello All,

I love this site, first post. I recently aquired a 1978 trihull with a 1982 70 HP Evinrude. It runs great but I would like to add a tach.

I understand that the OMC throttle accessory plug can accomadate one but something is all ready plugged into it. When looking at the 3 pin plug, the right most pin has a wire coming out of it. I appears to be running forward. I don't have much in the way of gauges. Just trim, horn, lights and bilge pump. What might it be for?

What tach do i need and harness do I need and how do I incorporate the existing plug?

Here's a couple of photos of boat and dash.

Did I mention I love this boat?

Thanks in advance,

Jack

 

[wilde1j]

Re: OMC Throttle accessory wiring

Someone may have used this pin for something other than a tach. If it's the purple, it's a switched 12Vdc. Find out what it feeds and find another source, then get the tach harness from an Evinrude dealer.

 

[lazersnake]

Re: OMC Throttle accessory wiring

Thank you. The diagram helps.

I'm worried about unplugging it. Could I unplug and fire it up and see what doesn't work or could that cause problems?

Jack

 

[wilde1j]

Re: OMC Throttle accessory wiring

Trace the wire ... easy.

 

[lazersnake]

Re: OMC Throttle accessory wiring

Duh (on my part)... of course. Thank you. I'll do that tonight.

 

[Sixmark]

Re: OMC Throttle accessory wiring

Tracing the wire is the best way as Wild said, but no you are not going to hurt anything by unplugging it at the control box.

If you are going to install a tach, the black wire is ground, purple is 12v accessory, and grey would be your tach signal wire.

 

[Sixmark]

Re: OMC Throttle accessory wiring

be carufel when installing your tach that it isn't to close to your compass as it could as there could be interference

 

[lazersnake]

Re: OMC Throttle accessory wiring

Thanks guys.

Any suggestions for a nice simple matching tach?

It's a 1982 70 HP Evinrude. I'm assuming a 6k tach should do...?

Jack

 

[Sixmark]

Re: OMC Throttle accessory wiring

if you want to get one to match your trim gauge try going with a simple Detmar, they were used in alot of boats from that era, you can even find complete NOS Detmar gauge sets for around $120

 

[lazersnake]

Re: OMC Throttle accessory wiring

You mentioned not too close to the compass. How close is too close?

Jack

 

[Sixmark]

Re: OMC Throttle accessory wiring

the rule of thumb was ro try and keep them 10-12" away from each other, it's not so bad considering most dash panel are at least 18" wide

 

[lazersnake]

Re: OMC Throttle accessory wiring

Yup, traced the one wire coming out of the "a" connector. It's power for the trim gauge.

I'm having trouble finding a OMC accessory harness. Does anyone know where to get one, or at least, the model number for it?

Also, I want to install a tach. Any tips on how to cut into the old fiberglass dash. I'd think I'd cry if I screwed it up.

Jack

 

[nymack66]

Re: OMC Throttle accessory wiring

Search Ebay tons of OMC accessory harness
Use a hole saw to cut through any fiberglass nice and clean cut use caution and nice and slow you will be proud ...

 

[Sixmark]

Re: OMC Throttle accessory wiring

If the plug that the wire is coming out of for your trim is in a plug and that plug is plugged into the control box then you can just get 2 of the pin style connectors, solder them to some wire and put them in the plug as well.

the following diagram will show you what you need to wire into

http://lh3.ggpht.com/_-Ppvw4qmZC4/TGf8MgcZWHI/AAAAAAAAAD4/SLd9gxUKzfc/s512/REMCONTBOX.jpg

Purple is accessory 12volr, grey is tach signal.

 

[lazersnake]

Re: OMC Throttle accessory wiring

Search Ebay tons of OMC accessory harness
Use a hole saw to cut through any fiberglass nice and clean cut use caution and nice and slow you will be proud ...

You would think that eBay would have tons of them... not a one...

...sigh...

 

[lazersnake]

Re: OMC Throttle accessory wiring

Made my own! I found some bullet ends that are almost big enough. Put a little bend in them to make contact in the harness and I'm ready to go.

This weekend will tell...