Tach not working...different from the ?tach problems" post

[xXTJTHEBOATER95Xx]

I'm having similar problems with my tach like the other guy that just posted about his recently. although I need to figure out if it is the tach that is faulty or the regulator/rectifier.

I have a Faria system check tach for my 2001 Johnson 115 Ocean Pro.

The battery in my dual battery system that I use the most is getting charged as I can see the volt gauge on the dash is giving a value while running( opposed to not giving a value like if the needle was stationary if I went to use an accessory). Not sure how to put that, but I'm sure it works.

This would lead me to believe that it would bee the tach rather than the regulator/rectifier but I want to see if I can test it first before having to guess on which thing to buy to fix this problem.

Also, the system check thing works when the ignition is turned on and all the lights go on and go off but the needle doesn't budge when the engine turns over.

I was told I could check the resistance in the wires from the tach to the R/R but I don't have a value in ohms to compare the reading I would get when testing them.

Thank you for any help in advance, you guys know best!!

 

[Joe Reeves]

Re: Tach not working...different from the ?tach problems" post

(Testing Tachometer With Water Cooled Regulator/Rectifier)
(J. Reeves)

A quick check is to simply plug in a another new tachometer as a piece of test equipment. If the new tach works properly and the old tach didn't, obviously the old tach is faulty.... but usually boaters don't carry around a spare tach (see below).

A faulty rectifier wouldn't damage the tachometer, the tachometer simply wouldn't work. This is due to the fact that the tachometer operates off of the charging system and the rectifier converts AC voltage to DC voltage, enabling the charging system. A faulty rectifier disables the charging system, and the tachometer simply doesn't register.

However.... those water cooled regulator/rectifiers that are used on the 35 ampere charging systems (and some others) bring into play a different type problem, and as you've probably found out, they are really a pain to troubleshoot via the proper procedure. There's an easier way.

The tachometer sending/receiving setup operates off of the gray wire at the tachometer. That same gray wire exists at the engine wiring harness which is connected to the engine electrical terminal strip. You'll see that there is a gray wire leading from the regulator/rectifier to that terminal strip, and that there is another gray wire attached to it. That other gray wire is the wire leading to the tachometer which is the one you're looking for.

NOTE: For the later models that DO NOT incorporate a wiring terminal strip, splicing into the "Yellow Wire" mentioned will be necessary.

Remove that gray wire that leads to the tachometer. Now, find the two (2) yellow wires leading from the stator to that terminal strip. Hopefully one of them is either yellow/gray or is connected to a yellow/gray wire at the terminal strip. If so, connect the gray wire you removed previously to that yellow/gray terminal. Start the engine and check the tachometers operation, and if the tachometer operates as it should, then the regulator/rectifier is faulty and will require replacing. If the tachometer is still faulty, replace the tachometer.

If neither of the yellow wires from the stator is yellow/gray, and neither is attached to a yellow/gray wire, then attach that gray tachometer wire to either yellow stator wire, then the other yellow wire, checking the tachometer operation on both connections.

I've found this method to be a quick and efficient way of finding out which component is faulty.... the tachometer or the regulator/rectifier. It sounds drawn out but really only takes a very short time to run through. If the water cooled regulator/rectifier proves to be faulty, don't put off replacing it as they have been known to catch on fire with disastrous consequences.

 

[xXTJTHEBOATER95Xx]

Re: Tach not working...different from the ?tach problems" post

I was able to try what you suggested, and the tach didnt budge. Does this mean that it's definitely the R/R, because the batteries are charging, so wouldn't that mean that the R/R is doing its job.

Just want to make it absolutely positive so I don't pay $200 for a new one when it is something else.

 

[Dogrider]

Re: Tach not working...different from the ?tach problems" post

I was able to try what you suggested, and the tach didnt budge. Does this mean that it's definitely the R/R, because the batteries are charging, so wouldn't that mean that the R/R is doing its job.

Just want to make it absolutely positive so I don't pay $200 for a new one when it is something else.

Help I'm also having tach problems. I talked to a guy that said if ur rect/reg is bad it will show 1000-1200rpms on tach and should still charge battery's. If stator is bad it will not charge, but u can still get 1000-2000rpms showing on tach. Please let me know what u find. I'm trying to learn as much as I can so I also don't buy stuff I don't need. Ill do the same.
Thanks Chris

 

[xXTJTHEBOATER95Xx]

Re: Tach not working...different from the ?tach problems" post

*just an update*

I was able to use my neighbors boat and hook the tach from that boat to my engine and it worked so I am having the Faria Tach/System Check gauge sent into Faria and hopfully they can find the problem and repair it.

 

[Joe Reeves]

Re: Tach not working...different from the ?tach problems" post

I was able to try what you suggested, and the tach didn't budge. Does this mean that it's definitely the R/R, because the batteries are charging, so wouldn't that mean that the R/R is doing its job. Just want to make it absolutely positive so I don't pay $200 for a new one when it is something else.

No change in the tachometer indicates a faulty tachometer.