No Power to the Water Temperature Gauge

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rd84
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No Power to the Water Temperature Gauge

#1 Post by rd84 » Thu Jun 22, 2017 8:18 pm

Hi,

There is no power to the water temperature gauge - no temperature reading and no background light - everything else on the bike is working normally - I put a different gauge and sub-loom on but still had the same problem.

Does anyone have an idea what the problem might be ?

Thanks.

Cheers
Paul

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phildu31
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Re: No Power to the Water Temperature Gauge

#2 Post by phildu31 » Fri Jun 23, 2017 8:19 am

Hi.
Background light is independent of the gauge with 2 wires : 1 Black/White (+12V) and 1 Black (ground).
It's easy to check.

Temperature gauge has 3 wires on the back : 1 Brown (+12V) to the connector marked with Br
1 Black (ground) to the connector marked with B
1 Green/Red from the thermo unit to the connector with no mark.
From memory, if you put the Green/Red to the ground, temperature should be at max.

rd84
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Re: No Power to the Water Temperature Gauge

#3 Post by rd84 » Fri Jun 23, 2017 4:18 pm

Thanks - I'll check it out this weekend.

Cheers
Paul

rd84
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Re: No Power to the Water Temperature Gauge

#4 Post by rd84 » Wed Jul 12, 2017 6:41 am

Hi,

Some progress - the bulb holder terminals were corroded - so now the background light is fixed

On the back of the gauge there are brown , black and green/red wires - all 3 test to ground with the ignition on and off - however the needle on the gauge doesn't move

What should I do next ?

I am a complete beginner with electrics so it is all quite confusing right now.

Thanks

Cheers
Paul

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phildu31
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Re: No Power to the Water Temperature Gauge

#5 Post by phildu31 » Wed Jul 12, 2017 7:19 pm

Hi.
First of all, check that you have +12V on the brown wire with ignition key on.
If not pick a wire directly from the battery to test.
Black wire seems good if it is to the ground.
Once you have +12V to brown connector and ground to black connector, put the green/red connector of the gauge successively to the ground and to +12V : the needle shoud move.
And then check the thermo unit with an ohmeter : it is just a resistor varying with temperature.
Thermo unit is still available from Yamaha, and temperature gauge is easy to find : same model as late 350s.
Let us know what you found.

rd84
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Re: No Power to the Water Temperature Gauge

#6 Post by rd84 » Wed Jul 12, 2017 10:01 pm

Hi,

I've done all the checks suggested....

There is no continuity on the red/green wire within the main wiring loom ! The sub loom to the gauge is ok - but the corresponding pin on the connector plug from the main loom is a green/ white wire not red/green!! - I can't see a red/green wire exit the main loom - There is no indicator canceller unit which I think is something to do with the green/white wire ? Perhaps I should put in an independent red/green wire from the sender all the way to the temperature gauge ?

Looks like the main loom has been modified incorrectly ?

Thanks for your help with this - much appreciated

Cheers
Paul

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Re: No Power to the Water Temperature Gauge

#7 Post by phildu31 » Thu Jul 13, 2017 7:09 pm

Hi.
Yes it looks ...
So possibly the red/green wire is cut in the main loom and you'll have to rewire it directly from the therm unit
And yes, the white/green is used by cancelling unit. If you don't use this unit, white/green is useless. Just plug the yellow/black male connector near fuse box on right hand side into the black female connector.

rd84
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Re: No Power to the Water Temperature Gauge

#8 Post by rd84 » Fri Jul 14, 2017 7:54 am

Thanks for being so patient explaining this stuff to me. After 12 years doing nut,bolts and painting electrics are a new learning curve.

I'll let you know how I get on - I've ordered green/red colored cable and the connectors to try and make a nice job of it even if not quite standard.

Cheers
Paul

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Re: No Power to the Water Temperature Gauge

#9 Post by rd84 » Sat Jul 22, 2017 12:38 pm

Finally fixed the problem by-passing the wiring loom altogether from the temperature sender to the temperature gauge - earthing this green/red wire does give a full needle deflection on the temperature gauge if anyone else has any problems with this.

Thanks for all the help and suggestions.

Cheers
Paul

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Re: No Power to the Water Temperature Gauge

#10 Post by phildu31 » Sat Jul 22, 2017 3:05 pm

That's a good job.

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