*FIXED* Tach, Regulator problems on my Johnson GT100 (J100STLCEM)

tlocus73

Seaman
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Aug 18, 2008
Messages
51
Hello,
Was having some Tach gauge/reading problems such as intermitant readings, then drop to '0'. Also when at '0' increasing the throttle would make the tach read rpms again.

Started to go through all the wiring, continuity, remove misc. corrosion, etc...
Also, a while back, I had the VRO pump disabled (a few lines plugged and a wire added or rearranged? ...can't recall).
There is a cable with a plug coming off of the main red connector inside the engine. This connector cable contains 4 wires which I believe are; white, grey, purple & tan). These go to the VRO pump.

Even with my VRO pump disconnected/not used, do I still need to have this connected up to the VRO pump?

Is the grey wire in this harness related to the Tach.? (I believe I did a continuity test and it was connected to the grey tach. wire on the terminal board in the engine.

I have a few pics below.

This is the remote control box diagram. This is pretty much an exact match to mine.


This is in the engine. There are a few differences: terminal block wiring is not the same, and not exactly sure about the 'remote control' connector is wired up(different than on the actual remote control). Also there is the connector/cable that goes to the VRO pump (not shown in this diagram)


And here, a rough hand drawn diagram of how the VRO pump is connected. ***White wire is actually Black


Here is a pic of the VRO connector on my engine:


Any help appreciated,

Thomas
 
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Joined
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2,906
Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

tach is the grey wire and if the vro is disabled then the vro does not need to be plugged in. If you have a voltmeter on the dash can you tell us what that gauge does when the tach drops to zero?
 

tlocus73

Seaman
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Messages
51
Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Sure,
Just a quick question... I set my multimeter to AC volts and measure + to signal and - to GND, correct?
 

tlocus73

Seaman
Joined
Aug 18, 2008
Messages
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Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Ahh, also have a Dwell/TACH meter. Could I connect this up to the grey wire coming from the regulator and gnd to get a reading?

t
 

emdsapmgr

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11,551
Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

The grey wire is the signal wire for the tach. It gets it's rpm signal from the combination rectifier/regulator sitting on top of the block. If the rectifier/regulator is not working properly, it's usually noticeable in the functioning of the tach first. The tach may or may not work, or it will work very oddly-such as the manner in which yours is working. Later, it may become evident that the battery is not being charged properly.
 

tlocus73

Seaman
Joined
Aug 18, 2008
Messages
51
Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Went ahead and got a new tach and everything works great now. Funny thing is I installed the old one that was giving me problems in a friends Yamaha 90Hp and it works..??? Any thoughts on this?

Also when you say it could be the rectifier/regulator going bad...slowly, would this send out a weaker pulse or tach signal to the gauge?

t
 

emdsapmgr

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Messages
11,551
Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

The rectifier/regulator on that engine is designed to regulate the charging current going back into the battery. Your device is somewhat newer (included a regulator feature) and keeps it from overcharging. Oh, yes, it also counts stator pulses and sends them to the tach. Usually when this device starts to act up, it's most visible in erratic tach readings. You may not notice that it has quit recharging the start battery till some day when it won't crank. If the original tach works fine on the other guy's boat, it's likely you may still have an issue with the rectifier/regulator, or might have been something as minor as a loose connection. Just keep an eye on it.
 

tlocus73

Seaman
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Messages
51
Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

You're right ...just started acting up. I tried Ezeke's method: installing the grey tach wire to the yellow/grey wire terminal and it works like it should. Looks like I need to get a rect/regulator.

I've heard some good things here on the forums about the ones made by CDI. Should I go with that? Didn't seem too bad at around $76..
I will have to get the gasket as well?
 

tlocus73

Seaman
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Messages
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Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Another question on the rect./regulator.
Been reading about the different 6, 10-35 Amp system (rect./regulators?). Is there anywhere on the engine that would tell me which one I need?
Seems like from what I've read it will probably be the 10 Amp one?

Thanks again,

thomas
 

tlocus73

Seaman
Joined
Aug 18, 2008
Messages
51
Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Another question on the rect./regulator.
Been reading about the different 6, 10-35 Amp system (rect./regulators?). Is there anywhere on the engine that would tell me which one I need?
Seems like from what I've read it will probably be the 10 Amp one?

Here is the one I was looking at:
193-4204 - REGULATOR, 585195
Replaces OEM #0583259. (10 Amp) Replaces: 583529, 584204,585195, 878331

Part Number
193-4204

Manufacturer
CDI Electronics


Also the gasket I should get with it:
0322858 - GASKET - WATER PASSAGE

My engine code is J100STLCEM

Thanks again,

thomas
 
Last edited:

Daviet

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Sep 24, 2008
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8,958
Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

According to the parts breakdown I was looking at, those are the correct part numbers.
 

tlocus73

Seaman
Joined
Aug 18, 2008
Messages
51
Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Is there anything on the engine to tell what Amp system it is (something stamped, etc..)? Or any other way of finding out?

thomas
 

emdsapmgr

Supreme Mariner
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Messages
11,551
Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

The factory parts lists (epc.brp.com) shows your engine was made at the factory with a 3/9 amp charging system-if the engine had power trim-which that engine probably had standard.
 

tlocus73

Seaman
Joined
Aug 18, 2008
Messages
51
Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Re: Trying to understand some wiring in my 1989 Johnson 100 V4 (with pics)

Just wanted to give an update.
I bought the CDI Regulator. Pulled the flywheel and unbolted the stator to get to the bolts of the regulator. Installed the new regulator + new gasket and everything works perfect :)

Thanks again for all the help,

thomas
 
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