Hooking up tach on Johnson 95 SPL

[sanmarc]

I recently bought a 95 Johnson 112 SPL off eBay and bought a tach for a 96 115 by mistake. The tach has a plugin on it and my control box has loose wires for the tach (3 wires). Can I cut the plug off the tach and hook wires so as to use the tach and foregoe the system check hookups? Or do I need to get another tach. I can send pictures of the tach if it helps.

 

[Joe Reeves]

Re: Hooking up tach on Johnson 95 SPL

Tach wires =<br /><br />Black = Ground<br />Purple = 12v when key is in ON position<br />Gray = Sensor<br />Blue (If it exists) = Instrument light<br /><br />The plug is for convenience of installation but it can be eliminated if need be.

 

[signfinder]

Re: Hooking up tach on Johnson 95 SPL

I bought one of those on ebay too and can't get it to work. Mine in a Lund brand. I tried to hard wire to a 1983 35 evinrude and it won't work..Any different ideas?? My plug has 8 o 9 wires..

 

[seahorse5]

Re: Hooking up tach on Johnson 95 SPL

Here is the wiring configuration for a System Check tach.<br /><br /><br />If you just want to use the tach function of the gauge, here's the pin configuration (looking at the back-side of the gauge, holding it upright):<br /><br />1-2-3-4<br />8-7-6-5<br /><br />Purple wire goes to pin 1- 12V<br />Black wire goes to pin 2- grnd<br />Gray wire goes to pin 3 - tach<br /><br />Grounding these pins, will activate the following:<br /><br />Pin 4, turn on no oil lite<br />Pin 5, turn on low oil lite<br />Pin 7, turn on check engine lite<br />Pin 6, turn on hot lite<br /><br />Pin 8, is used to activate the warning horn, it supplies a ground to the horn circuit when any other warning circuit (pins 4 thru 7) is grounded

 

[sanmarc]

Re: Hooking up tach on Johnson 95 SPL

Thank you Joe & seahorse. After getting so many answers from local marine dealers (basically said the tach would not work with my motor) it is really great to get your input - and so quickly! I will wire the tach this morning and post back re how it works today.<br /><br />signfinder - my tach is a Lund too so will let you know how it goes. I will match & label the wires per seahorse's pin config - then cut off the plug and connect to the 3 wires coming off the control box.

 

[seahorse5]

Re: Hooking up tach on Johnson 95 SPL

To make a neat and easy installation, order the 8-pin connector, wedge,seal, and the 3 individual socket terminals from your dealer. Then wire it up.

 

[sanmarc]

Re: Hooking up tach on Johnson 95 SPL

Have the Lund Tach installed and is working fine. Pin 1 is RED;2 is Black; 3 is Grey (on the plug). Snipped these wires and connected Red to Purple; blk to blk; and grey to grey. Left the rest of the wires hooked to the plug. Set the little dial in back or tach to point to 4cyl. Seems to register idle a bit high - at 1500 rpm(idled with muffs on) Will find out later on the water how it reads.

 

[sanmarc]

Re: Hooking up tach on Johnson 95 SPL

Had a glorious day with the wife at Lake Berryesa - and the tach seemed to work correctly . Idle was at 1200 rpm and WOT was up to 6200!! Am I right in assuming 6200 is high? Shouldn't WOT be 5200? Motor sounds fine at 6200 and before I had the tach I ran it WOT all day with no problems. Boat's at 47 mph at WOT. Is that good for a 112 SPL? Has a 115 Merc Inline 6 that leaned out on me and it only did 43 mph. Will I toast this motor at 6200?<br />Thanks.

 

[sanmarc]

Re: Hooking up tach on Johnson 95 SPL

That should read "had a 115 Inline 6" not has

 

[seahorse5]

Re: Hooking up tach on Johnson 95 SPL

I'm not familiar with the LUND tach, but an outboard tach is usually set to the "alt" or 6 pulse setting for your 112. The J/E factory tachs only have a 5 and 6 pulse settings on them.

 

[Indymike]

Re: Hooking up tach on Johnson 95 SPL

Assuming Lund tachs are made by someone else here are a couple places to look for proper settings<br /> teleflex<br /><br /> faria <br /><br />Mike

 

[sanmarc]

Re: Hooking up tach on Johnson 95 SPL

Set the tach switch to 6 cyl and it seemed to read better - idled at 1100 rpm vs 1500. White caps on Lake made it too choppy to go WOT. <br /><br />Signfinder - did you try hooking up your lund tach the way I did?

 

[sanmarc]

Re: Hooking up tach on Johnson 95 SPL

Aha! Yesterday I crawled under the dash with a light and low and behold on the Lund system Check Tach there is an Arrow on the little dial. The 6cyl setting is actually where the slot is pointing - the arrow is pointing at 6P. Tach works correctly with arrow pointing at 6P. You are giht Seahorse...thanks again.

 

[ob]

Re: Hooking up tach on Johnson 95 SPL

Just for future reference glastron1,the 6P denotes the number of alt poles of the engines charging system,not the number of cylinders.

 

[sanmarc]

Re: Hooking up tach on Johnson 95 SPL

"Alt" meaning alternator, right?

 

[signfinder]

Re: Hooking up tach on Johnson 95 SPL

Yes I hooked up the tach as you said and it works nice. I took the plug apart and had some ends that slides right in them that makes a nice neat job. thanks for the info

 

[ob]

Re: Hooking up tach on Johnson 95 SPL

That's correct glastron1.