1994 johnson 88spl Tach

[wht07se]

I am going crazy here...just recently purchased a 94 key west with a 94 model jonhson 88spl. The boat had gauges but the tach was bad. It constantly read 6500 no matter if motor was running or not. So i ordered a new teleflex sahara outboard tach. I hooked everything up just like it was and i even made sure the dial on the back was set to 6p. The wires that were hooked to the old tach were blk = ground, grey = signal, purple = ignition, and blue was the 12v+ lead for the light on the gauge. Now here is what i have...the tach will not even come on, directions say for trouble shooting that when the ignition is turned on the tach needle should bounce then remain on 0. I have none of that... but with the original gauge it did do the initial bounce but just read 6500 instead of 0. The directions say that if there is no bounce then to replace gauge.... this one is bran new... so is there something i am missing here or might i just have a faulty gauge? Any other way to test to see if it works?

 

[wht07se]

Re: 1994 johnson 88spl Tach

^^^^Bump for the am crew

 

[wht07se]

Re: 1994 johnson 88spl Tach

No one with any ideas?

 

[wilde1j]

Re: 1994 johnson 88spl Tach

Regulator rectifier or stator may be cooked. Is battery charging OK?

 

[ezeke]

Re: 1994 johnson 88spl Tach

Check the wiring back to the source. Make sure that the positive purple is positive and that the black negative has a solid ground. Use an ohmmeter to test, with the battery disconnected.

The gray wire will run to the terminal block on the engine. where it has to connect with rectifier connection at the union with the alternator lead.

The alternator will not work if the rectifier is bad. Test the unregulated rectifier: http://forums.iboats.com/showthread.php?t=190638

http://www.downloadingfiles.co.uk/teleflexfiles/gauges/page342.pdf

 

[wht07se]

Re: 1994 johnson 88spl Tach

Have not had any issues yet with the battery not being charged, only been out on the water with it for about a total of 3 hours. But i will go out and test the regulator/rectifier.

 

[wht07se]

Re: 1994 johnson 88spl Tach

I have triple checked the wiring back and all is well there, not when i go to test the rectifier i cant get any reading on my fluke, its set to read ohms but i get nothing. Any ideas what im doing wrong?

 

[Al-53]

Re: 1994 johnson 88spl Tach

I believe you put the meter on diode mode....u should nave a reading one way and not the other way....if its open both ways then the diodes are gone....

there is a test post here some where...to test the rectifier....

Al

 

[ezeke]

Re: 1994 johnson 88spl Tach

The link I gave before is the way to test the unregulated rectifiers.

That's OK though; put the meter on AC voltage and read from ground to sender on the gauge connections. You should read 5 volts AC or better with the engine running at idle speed.

Don't let any voltage at all ride the gray wire back or you will have a bad rectifier for sure.

 

[wht07se]

Re: 1994 johnson 88spl Tach

Now another quick one, yesterday when i was trying to figure out if the grey wire had an current coming to it i did use my cheap test light to see if it did, I grounded lead from light then touched the grey wire when bumping the motor over.. test light lit up for a sec then blew the lil bulb inside. Could this have maybe killed my rectifier?

 

[wht07se]

Re: 1994 johnson 88spl Tach

I finally figured out how to set my meter to test for diodes. An it reads nothing, so im guessing a bad part. So, i know this would cause the tach not to work but wouldn't the tach still bounce (set to 0) once the switch is on and power going to the gauge?

 

[wht07se]

Re: 1994 johnson 88spl Tach

An update, just to let yall know it turned out to be a bad rectifier and a faulty brand new tach. Got new part and new gauge and working fine now. But did find another prob but going to start new thread for that. Thanks again for all the help.

Bryan