My Tach Quit!

[dgirt]

I've read through many of the posts here on Iboats and could not find symptoms similar to mine. I have a 2000 Merc Outboard ELPTO 125. After replacing the fuel sender assy on the underfloor fuel tank, my tach quit working. I don't believe I disturbed anything that might have caused this, but was wondering if these symptoms ring a bell with anybody.

When I turn the key to on, there is slight movement in the needle.
When I crank, the needle moves WAY below zero and returns to zero when I quit cranking or when the engine starts.

I confess I have not done the troubleshooting on the rectifier (assuming it has one) but I hoped someone here may have run across this before and point out to something simpler (and less expensive) than the rectifier.

Thanks in Advance,

Dan

 

[j_martin]

Re: My Tach Quit!

Check your power and ground to the tachometer.

It gets it's signal from the grey wire coming from the voltage regulator. If your battery isn't charging, the VR is the problem, probably for both bugs.

hope it helps
john

 

[dgirt]

Re: My Tach Quit!

I have power and ground at the tach. I have not experienced any problems with a low battery but at this point I am reluctant to check charge rate since it is recommended not to do so on a garden hose. Near as I can figure I have a VR with 2 yellows, 2 reds 1 gray and 1 black. In the FAQ there is a procedure to check a rectifier but not sure if that pertains to VR's like mine. My results were:

Red wires had continuity to ground 1 way only
Yellow wires had same reading both ways.

If the rectifier procedure is the same as VR, then my VR would be bad correct?

 

[dgirt]

Re: My Tach Quit!

TTT

Still looking for some suggestions....

 

[dgirt]

Strange

Strange

I performed all the troubleshooting checks provided by CDI on their website with the voltage regulator hooked up. It was charging, it was sending a 6V pulse to the tach wire and I had power and ground to the tach itself. I removed the regulator to do a bench test with an ohm meter and while none of the values represented in the troubleshooting guide were present, I put the unit back in and everything works...Guess I'll say my prayers again tonight and hope it stays working. Thanks for trying even if it wasn't so hard!

 

[SC1650]

Re: My Tach Quit!

Evidently it was just a hiccup in the system. When my tach quit, it was the rectifier. I have had to replace it twice so far. Mine is a much smaller engine but has the same function.

 

[Silver Eagle]

Re: My Tach Quit!

On a 90 hp two stroke Mercury engine where is the rectifier and what does it look like.

 

[j_martin]

Re: My Tach Quit!

On a 90 hp two stroke Mercury engine where is the rectifier and what does it look like.

Depends. Where on the evolutionary scale is your engine?

 

[Silver Eagle]

Re: My Tach Quit!

I don't understand the question.

 

[ibrnrbr]

Re: My Tach Quit!

What year?

 

[j_martin]

Re: My Tach Quit!

I don't understand the question.

Merc has gone from 9 amp rectifier that's all you got to belt driven self contained alternator over the years, with many steps in the evolution.

Generally, though, you can follow the yellow wires from the stator to whatever device your engine has. It's an oz thing.

 

[Silver Eagle]

Re: My Tach Quit!

what year?

2007

 

[Silver Eagle]

Re: My Tach Quit!

A couple of days ago I got a phone call from Mercury service center. I spoke with a women about my problem. She sent me a engine Diagram of the wiring for the motor. Today I took the instrument panel apart and looked for a gray wire that went from the tach to the VR. The connector on the boat didn't have a gray wire ,so I looked around until I found one that did.This isn't the hook up that was on the tach.I hooked it up and started the motor and the tach worked. So the first tach wasn't hooked up the proper way and the new one works.