1996 Evinrude 112 SPL Tach problem (FIXED FOLLOW-UP)

[lvin4jc]

1996 Evinrude 112 spl - Last outing, tach went inop....and I live by my tach!!! Talked with a few local folks about the problem...and ordered a new tach. Installation per instructions and still does not work.

Looked in the manual and I could not find a troubleshooting procedure for a tach indicating system. I have a digital multi-meter and electrical knowhow....however I fell short of finding the problem. Can I impose on you experts to give me a hand in troubleshooting?

I am guessing the stator puts out an electrical signal (AC or DC???) that varies with engine (flywheel) rotation. I just need to know what exactly to check for, and where (at least I hope it?s that simple).

Also, the old tach had a resistor between the "send" terminal and ?ground? posts however, the instructions did not call for this resistor, nor did it come with a new one.

Thank you in advance for your time and expertise.

 

[Barnacle_Bill]

Re: 1996 Evinrude 112 SPL Tach problem

Re: 1996 Evinrude 112 SPL Tach problem

Test your rectifier. Your tach runs off AC pulses from the stator. The connection is made at the rectifier. So if a diode in the rectifier shorts, it kills the signal to the tach.

 

[Bifflefan]

Re: 1996 Evinrude 112 SPL Tach problem

Re: 1996 Evinrude 112 SPL Tach problem

the resistor may have been a diode. the new one may have it inside.
As to the problem, being your elec. inclined. Im going to assume that you ohm'ed the wire and checked all the conections.
Did you also check for power to the tach?
You may try running a new wire just to test it, and also off a different power supply.
Short of that i got nothin...

 

[lvin4jc]

Re: 1996 Evinrude 112 SPL Tach problem

Re: 1996 Evinrude 112 SPL Tach problem

the resistor may have been a diode. the new one may have it inside.
As to the problem, being your elec. inclined. Im going to assume that you ohm'ed the wire and checked all the conections.
Did you also check for power to the tach?
You may try running a new wire just to test it, and also off a different power supply.
Short of that i got nothin...

12 vdc at tach when key is turned on. Visually checked and (shook test) engine and boat harnesses while running to see if could get the tach to bounce....no joy. Good grounds also

My sense is telling me to check at the engine and work my way forward....i just don't know where on the engine to check for the tach signal, or what the value should be at idle??

 

[lvin4jc]

Re: 1996 Evinrude 112 SPL Tach problem

Re: 1996 Evinrude 112 SPL Tach problem

Bhile - How exactly do i test the rectifier?? Any special equipment or will a digital multimeter do the trick. Thanks for the help!!

 

[wilde1j]

Re: 1996 Evinrude 112 SPL Tach problem

Re: 1996 Evinrude 112 SPL Tach problem

You can start by testing the battery voltage with the motor fast idling. If < 13 VDC, the rectifier/regulator and/or stator may be bad. There are diode tests for the rectifier/regulator in the shop manual. Also, the stator AC output can be verified by measuring AC voltage across the yellow that feed the reg/rec ... you should get > 30 VAC. If the stator is NG, the tach won't work either.

 

[lvin4jc]

Re: 1996 Evinrude 112 SPL Tach problem

Re: 1996 Evinrude 112 SPL Tach problem

You can start by testing the battery voltage with the motor fast idling. If < 13 VDC, the rectifier/regulator and/or stator may be bad. There are diode tests for the rectifier/regulator in the shop manual. Also, the stator AC output can be verified by measuring AC voltage across the yellow that feed the reg/rec ... you should get > 30 VAC. If the stator is NG, the tach won't work either.

Wilde1J - Great advice! Unfortunately, I have to shell out some $$ for parts. Hope the forum does not mind me being thorough with this "result" post but it may help someone else looking to cure a tachometer/charging problem.

Fast idling VDC battery check (above) - only 11.7 vdc at battery.

Stator A/C output (above) - 0.0 VAC at yellow lead at terminal block.

Stator resistance check (tech manual) - 1.25 ohms (which is good).

Stator short-to-ground test (tech manual) - straight short to ground 0.00 ohms on both yellow and yellow/gray leads.

Rectifier ohmmeter (positive and negative diode test) - positive diodes where good. Negative diodes where bad.

Appears I need to order both rectifier and stator assembly. Not sure how much...but I?m sure it's more than dinner at Outback!!

Now for the final (but important questions)....what could have caused the stator/rectifier to fail? What else....if anything, do I need to check to make sure this is money spent only once?? Also....during replacement of the stator, are there any "do's or don'ts" when performing this task? The manual looks pretty straight forward.

Thanks again for your time Wilde1J!! I will post a "fixed" post once I get my baby going again.

 

[wilde1j]

Re: 1996 Evinrude 112 SPL Tach problem

Re: 1996 Evinrude 112 SPL Tach problem

If the stator has no AC out, it's clearly bad. No special tips for installing a new one ... just orient the wire harness in the same place the old one has. Be careful to secure the harness so it can't rub. That's about it. It is expensive, BTW.

 

[Barnacle_Bill]

Re: 1996 Evinrude 112 SPL Tach problem

Re: 1996 Evinrude 112 SPL Tach problem

Did you have the wires disconnected from the rectifier when you did the ohm tests on the stator?

 

[lvin4jc]

Re: 1996 Evinrude 112 SPL Tach problem

Re: 1996 Evinrude 112 SPL Tach problem

Did you have the wires disconnected from the rectifier when you did the ohm tests on the stator?

Yes...the two stator leads were diconnected from the terminal block when i did the stator "ohm test" . Book called it a stator short-to-ground test.

Have a new stator and rectifier on order.

Thanks for all you help, and i will post a follow-up after new parts are installed.

 

[lvin4jc]

Re: 1996 Evinrude 112 SPL Tach problem (FIXED FOLLOW-UP)

Replaced both stator and rectifier and all is well. Tach is now working and the batteries are charging. Old stator had an obvious (visual) short.

FYI - the old stator looked considerably different that the OEM part. The old part had a rubberized coating and the new part did not. Flywheel is a little tricky so make sure you have a manual and the right puller.

Hope this thread helps someone else!!

This is a great forum!!

 

[wilde1j]

Re: 1996 Evinrude 112 SPL Tach problem (FIXED FOLLOW-UP)

Thanks for the FB and glad you're back running.