Installing Tach on 110 Johnson

[southernyooper]

I recently purchased a 1986 Bomber with a 110 Johnson VRO. There was no tachometer or speedometer on the boat, so I purchased both from Teleflex. Found out there was a wiring harness for the 86 Jonhson 110 VRO, so I ordered that as well.<br /><br />Hooked everything up according to directions, and took it out on the lake this weekend. Tachometer reads intermittently. Sometimes it appears to read correctly, sometimes it doesn't work at all. Any suggestions on how to correct this?

 

[kirkland]

Re: Installing Tach on 110 Johnson

Sounds like you have a poor connection somewhere...I’d check the connections on the gauges first...does you Speedo fluctuate of just the tach????....is the tach set to 6P on the back ..???

 

[southernyooper]

Re: Installing Tach on 110 Johnson

DEIFan,<br /><br />Thanks for the response. The speedometer was initially going all over the place, but it seemed to get better as the day went on. A friend thought the speedometer problem was air in the line, and if I removed the hose from back of speedometer at slow speed until water came through, it would fix the problem. However, it seemed to take care of itself after a while. It still seemed to "jump" sometimes, but when cruising it remained fairly steady. The only electrical connection on the speedometer is for the light, and those connection are secure.<br /><br />On the tachometer, I went and checked the connections, and found the one to the ignition had come loose. The harness has the fittings that slip over the posts on the gauge, and I think I will replace with a more secure connector. The tach is set to 6P.<br /><br />The 3-pin socket that I plugged the harness into, already had a plug in it, which was for the fuel and trim/tilt gauge. Can I splice this wire into the new harness, that enters in the same pin position?

 

[kirkland]

Re: Installing Tach on 110 Johnson

'The Three wires you should have coming from your plug are<br /><br />1.Black(ignition ground)<br />2.Purple with black stripe (ignition +12V)<br />3.Grey (To Tach "S")<br /><br />Basically the ignition power and ground...will be run to all gauges trim,tach,speed,fuel...whatever gauges you have….you may also connect the +12v to the lamp post on your gauges or you may have a switch that controls the power to these posts...you can splice as many leads into this harness as you need to make all of your connections...or run a jumper from one gauge to the other...that's how mine is wired...<br /><br />The grey needs to be connected to the tach's "S" post, which it probably is if your are getting a reading from your tach right now.<br /><br />I bet after you have the wiring secured it will cure your problem. ...If not let us know....we'll go from there...

 

[southernyooper]

Re: Installing Tach on 110 Johnson

DEIFan,<br /><br />Thanks again! I will change the connectors and see how it works this weekend on the lake.<br /><br />Jumping the power to the other gauges might be the best way to get all the gauges working again. Thanks for the advice.

 

[kirkland]

Re: Installing Tach on 110 Johnson

No problem...it seems to be a little cleaner....but if loose connection on first guage inline you stand to loose all ....but tight is always good....

 

[southernyooper]

Re: Installing Tach on 110 Johnson

Changed all the connectors and jumped the power to the other gauges. When I put my boat on the water today, speedometer, fuel and tilt/trim gauges work fine. Still having a problem with the tachometer.<br /><br />When it idles or runs at low speeds, everything is OK. When it hits 2000 RPM, the needle drops back to zero and stays there. When the RPM's drop below 2000, it engages again and works fine.<br /><br />I'm new with all this, so any help is greatly appreciated.

 

[jarob]

Re: Installing Tach on 110 Johnson

if you have an ammeter on board can you see if the charger is working all the time or does it stop at the same time the tacho cuts out

 

[kirkland]

Re: Installing Tach on 110 Johnson

could be a rectifier going south.....or north however you look at them... Is it always tied to the 2K RPM range ??? Like Jarob says check that you are getting good voltage while at this RPM.... I think this would point to the rectifier...I think ...

 

[southernyooper]

Re: Installing Tach on 110 Johnson

Yes, the problem always happens around 2000 RPM. How exactly do I test the system to see if the charger is working, and how is this tied to the tachometer?<br /><br />I ordered a repair manual yesterday, so hopefully I can start to understand things a little better.