Tach going wild and Volt meter at 15-18 volts - What could be wrong?

[benzguy777]

Hello,

I have a 1997 Fast Strike 150. I removed the fuel guage, took out wirings at the back and put them on again. After this, my tach was going crazy. It would jump all over the dial and sometimes turn around. My engine was working ok though. I also noticed the Volt meter was reading 15 volts at idle and 18 volts at around 1,500-2000 rpm.

Did I ground some wires or is my voltage regulator shot? How to I test my voltage regulator if this is really busted? I have a digital voltmeter - would it be correct to test the voltage at the battery during idling and 2-3K rpm? If more than 14v will this indicate that the Vreg is damaged?

Can I still use the boat or you recomment not to anymore until the fix the Voltage Regulator problem? I am worried it might damage the batteries, Lights, Guages and radio.


Thanks in advance for the help!


Francis

[ChampioNman]

Regulator/Recitfier.

[SEAHORSE]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by benzguy777 &raquo;</TD></TR><TR><TD CLASS="quote">Hello,

I have a 1997 Fast Strike 150.

I also noticed the Volt meter was reading 15 volts at idle and 18 volts at around 1,500-2000 rpm.

Did I ground some wires or is my voltage regulator shot?
</TD></TR></TABLE>

First you have to find out if the voltmeter is accurate. With the key ON and motor not running, does the voltmeter show about 12 Volts, or something different? You can also put a digital multimeter onto the battery and read the voltage and compare that to your dash voltmeter.

[benzguy777]

I'll go and check voltage now. I will post updates of my findings.

If the Digital Voltmeter really reads high, say 14V at idle and 15-18V at 1500-2K rpm, can I still use the boat until I replace the Voltage Regulator? Or will this damage my guages, battery, vhf radio, etc.?

Thanks so much for the help!


Francis

[RUSTY63]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SEAHORSE &raquo;</TD></TR><TR><TD CLASS="quote">

First you have to find out if the voltmeter is accurate. With the key ON and motor not running, does the voltmeter show about 12 Volts, or something different? You can also put a digital multimeter onto the battery and read the voltage and compare that to your dash voltmeter.</TD></TR></TABLE>

I think you need to read Seahorse post again, also with the wiring changes you made......maybe you wired something wrong?

[benzguy777]

Here's what I did. With Ignition ON only (Not engine start) Dash voltmeter reads 15V.

I put a Fluke Digital Voltmeter straight to the battery it read 12.98v (Iginition off), (12.50v ignition on) Started the engine and it was 13v on idling, 14.8volts at around 2-3K rpm.

I removed the Dash mounted voltmeter and mounted it directly to the battery and it hit 15v. I also mounted this to a bnew spare battery not connected to anything and it also hit 15v. Can I therefore conclude that the Dash Mounted voltmeter is busted?

I tried to trace back what I did, and I remember pulling out all the fuses (so I dont short out anything) on the fuse box. I then turn the Ignition to ON position forgetting that there was no fuse and the tach was jumping all over. I immediately turned the ignition off again and installed all the fuses and my Tach was going haywire and Voltmeter at 15v already. - Could this have caused the tach and voltmeter malfunction?

With regards to my Voltage Regulator, is there a way to test this if it's working or not. I just want to make sure that it's OK. I see a gray and purple wire on it. Can I test this with a Digital Tester on DC Voltage output?


Thanks so much!


Francis

[RUSTY63]

Sounds like your volt meter needs replacing.

To check your tach rectifier/regulator......use a volt meter set to DC volts and attach the Red lead to the sender post on the tach and the black lead to the ground post on the tach, start the motor (with water of course) the volt meter should show 9 volts at idle, if not you need a rectifier/ regulator, if you see 9 volts you need a tach.

If you have a System Check tach and only have a plug in the back of the tach the easiest way to check it is to use a known good tach.

[benzguy777]

Thanks so much for the tips Rusty!

Yah I have a system check tach which has plug-in at the back. And the dealer here won't allow their unit to be tested as it might get damaged when I plug it in. I have to buy it if I want to test it.


Is there no other way to test the Voltage Regulator? The part number of my regulator is 586048.


Thanks again!


Francis

[benzguy777]

I did a test which a local mechanic suggested. Don't know if this is correct though.

He told me to tester (12v DC) the Gray and Purple wires coming out of the Voltage Regulator (0586048).

Results are:

Ignition switch ON=12.55v
Start the Engine Idling=7.5volts
Rev to about 2-3K rpm=9.4volts

Is this basis that my Voltage regulator is going bad already? When I tester the battery though with Engine idling it shows it's charging at 13v and 14.8v at 2-3K rpm.

I will order the Voltmeter already. Just want to make sure whether it's the RPM gauge or the Voltage Regulator as the price of the RPM gauge here is about the same as the Regulator (US$300).

If the regulator is indeed busted, is this the correct part #? (0586048) http://www.ishopmarine.com list a 18-5829 part. Is would anyone know if this is still made by OMC? Who makes OEM parts for Johnson Outboards now?

Thanks for the comments!


Francis