Intermittent Tach.

[kapaafire]

Would you believe it, when you just get one thing running another goes down.

Sometimes my tach works and other times it doesn't.

Checked the wires behind the console and everything seems O.K. I also recently installed a GPS, so I figured it might be some loose wires or something, no chance.

Where do the tach wires attach at the power head? Is it at the rear of powerhead, in the black box between the heads?

Thanks in advance

 

[ob]

Re: Intermittent Tach.

What engine? The tach get its feed from the gray wire leading from the reg/rec unit on many John/Rudes.Sometimes a tach that is acting up is a sign that the reg/rec is going bad.First eliminate any loose connections.Particularly the gray wire on the ?engine? terminal block.

 

[kapaafire]

Re: Intermittent Tach.

Motor is a 83' 115 hp evinrude.
The wiring diagram in my Clymer manual not that specific.

 

[kapaafire]

Re: Intermittent Tach.

Thanks OB, I will check the terminal board tomorrow.

Is there anyway to check the regulator/rectifier w/ a multimeter? Are they expensive to replace?

 

[ob]

Re: Intermittent Tach.

Try checking the voltage across the battery terminals ,first with the engine off ,and then with the engine running either in water or on the hose and see if the voltage increases from 12 to 13.5 -14 VDC.This will at least tell you if it's charging or not.If your engine has power tilt and trim which I don't know without a model number ,then it has a voltage regulator.Otherwise it just has a three lead rectifier unit.

 

[ezeke]

Re: Intermittent Tach.

You might also want to:
open and clean the connections on the large red plug at the engine;
clean the black ground wires connected to the engine near and on the starter solenoid;
and, clean terminals 2 and 3 on the terminal block.

The gray wire should be connected to terminal 3 which crosses over to terminal 2. Terminal 2 receives the pulse from the grey and yellow wire and is also connected to one side of the rectifier.

You can test the system by running temporary wire from the terminal block post 3 to the tach and a ground wire from the engine block to the tach.

Edit: Never apply any voltage to the gray wire.

 

[MASTER Brian]

Re: Intermittent Tach.

Sounds just like what my tach had been doing prior to a PH rebuild, which also led to a new rectifier. After replacing the rectifier the tach worked great.

I forget exactly, but I believe the rectifier on my XP150 was $200+. I believe you can look up the part on this site....

 

[kapaafire]

Re: Intermittent Tach.

Thanks guys for all the info, very helpful.

I will mess with it tommorrow. Wholly smokes!!! A new rectifier is not cheap. Hopefully it just a bad connection somewhere.

I will post back later.

 

[kapaafire]

Re: Intermittent Tach.

OK, went trolling the other day for six hours.
Everything went well. Except, tach still worked.....sometimes.

Finally checked the voltage across the battery during idle.
The multimeter read 11.99 to 12 volts at idle.

Isn't it supposed to be at 13 Volts?
Bad regulator, rectifier?

Thanks in advance

 

[kapaafire]

Re: Intermittent Tach.

Battery also reads 11.90 when static. Basically no charge to the battery while the motor is at idle.

Doesn't the charging system have some sort of trickle charge to the battery?

 

[kapaafire]

Re: Intermittent Tach.

It is a 83' powerhead w/ an 84' power trim/tilt leg.

Head model #: E115TXCTE
Leg model #: E115TLCRD

The reg./rect. is a round object w/ 3 wires coming out of it.
1) Yellow w/ a stripe
2) Yellow
3) red

They are all connect to the terminal board.
There are 2 set of numbers on the rect./reg.

1) 511 938 (engraved/stamped near the lower bolt)
2) 17 BIF DA (located on the circular part)

Which one is the part number?
Should I replace it with Sierra part #: 18-5708?

Would the diff. in powerhead and leg affect the rect./reg.?

Isn't the 83' manual, while the 84' power tilt/trim?
Which wiring diagram should I follow in my Clymer Manual?

Sorry for all the questions, but assistance would be appreciated.

 

[kapaafire]

Re: Intermittent Tach.

More info:

I can't seem to find the regulator on my motor. The wire at the terminal board leads across toward the port side of the motor. I don't see anything that resembles it like the picture in my manual.

Purple and yellow wires are attached on #1 and #5 respectfully.

Do I need to replace it w/ a rectifier w/ regulator part?

 

[ezeke]

Re: Intermittent Tach.

You do not have to regulate the voltage from the rectifier if you use the correct battery.

http://rapair.com/index.php?option=com_content&task=view&id=51

If you want to regulate the rectifier you can, but it is relatively expensive.

You can check the unregulated rectifiers with an ohmmeter. The yellow wires connect to blocking diodes. The rectifier's case is ground. Switch the test leads; you should get flow in only one direction for each wire.

 

[kapaafire]

Re: Intermittent Tach.

Ezeke,

Thanks for the link, informative.
I do have a 24 class, deep cycle marine battery. After several hours of trolling, my battery had a hard time cranking the engine. I switched to my spare and it started right up.

Would a bad rectifier affect the charging of my battery?
I'm going to change the darn thing anyway, but just wondering if I need to do anything else.

Thanks again

 

[ezeke]

Re: Intermittent Tach.

The rectifier is the only source of charging DC voltage for the battery. The rectifier takes the alternating current and converts it to direct current by using the diodes to allow flow in only one direction. That produces the 12 volts DC you need to charge your battery,

The rectifier sold here at Iboats is good for your application, or you can get it from your local dealer and save the shipping charges.

http://www.iboats.com/Cdi_Rectifier...20552124--list_time.1173698870--view_id.47460

http://www.iboats.com/mall/partfind...ow=68&keywords=rectifier&session_id=222083135


I usually just put the voltmeter on the battery with the engine off and then do it again with the engine running. If the voltage isn't up, it is usually the rectifier.

Often the erratic tachometer problem is because only part of the rectifier is bad - that's when you need to remove the rectifier and check each lead. If you remove the rectifier, make a map of the connections first so that you will rewire it correctly.

 

[WillyBWright]

Re: Intermittent Tach.

I just want to add that the leading cause of failed rectifiers is crossed, loose, or corroded battery connections.