Broken Temperature Gauge

731 Views 19 Replies 7 Participants Last post by nolimitz, Mar 22, 2022

kevinmci

Discussion Starter · Mar 21, 2022

Hi everyone! I was reading the forums about broken temperature gauges, since I do not believe mine is working since it hasn't moved at all even after riding around for 20ish minutes. I'll have to pick up a Haynes manual to learn more about the cooling system (and because they're awesome), but my only concern is does coolant flow if the temperature gauge is non-operating?

1 - 20 of 20 Posts

reclinedrelic

· #2 · Mar 21, 2022

Coolant flows even with a non-operating temperature gauge.

The temperature gauge, assuming stock, is supplied 7 volts from the 7 volt regulator and the amount of current depends on the resistance in the temperature sensor. Failure points include the 7 volt regulator, the gauge itself, the temperature sensor and the wiring connecting the components.

An excellent accompaniment to the Haynes manual is the factory service manual, available for free download.

Reactions: 1

kevinmci

Discussion Starter · #3 · Mar 21, 2022

reclinedrelic said:
Coolant flows even with a non-operating temperature gauge.

The temperature gauge, assuming stock, is supplied 7 volts from the 7 volt regulator and the amount of current depends on the resistance in the temperature sensor. Failure points include the 7 volt regulator, the gauge itself, the temperature sensor and the wiring connecting the components.

An excellent accompaniment to the Haynes manual is the factory service manual, available for free download.

That's good to know, thank you!

kevinmci

Discussion Starter · #4 · Mar 21, 2022

reclinedrelic said:
Coolant flows even with a non-operating temperature gauge.

The temperature gauge, assuming stock, is supplied 7 volts from the 7 volt regulator and the amount of current depends on the resistance in the temperature sensor. Failure points include the 7 volt regulator, the gauge itself, the temperature sensor and the wiring connecting the components.

An excellent accompaniment to the Haynes manual is the factory service manual, available for free download.

If I understand correctly, the fan kicks on based on the temperature sensor measurement? Is the temperature sensor in the thermostat?

bahn88

· #5 · Mar 21, 2022

Could be the temp sender...as the 7v regulator tends to give wavering readings instead of no reading.
You will probably have to open up the instrument nacelle if yours is a std model.

First id make sure i can feel warmth in the radiator hoses, check the coolant level, and ride for 20 minutes or so again....

I ended up just fitting an accessory gauge at the handlebar on mine....

kevinmci

Discussion Starter · #6 · Mar 21, 2022

kevinmci said:
If I understand correctly, the fan kicks on based on the temperature sensor measurement? Is the temperature sensor in the thermostat?

Actually if it's off the camshaft I assume it should be operating all the time.

kevinmci

Discussion Starter · #7 · Mar 21, 2022

bahn88 said:
Could be the temp sender...as the 7v regulator tends to give wavering readings instead of no reading.
You will probably have to open up the instrument nacelle if yours is a std model.

First id make sure i can feel warmth in the radiator hoses, check the coolant level, and ride for 20 minutes or so again....

I ended up just fitting an accessory gauge at the handlebar on mine....

Makes sense. Okay I'll make sure to feel the radiator hoses next time I turn her on! I just topped off coolant before the last ride, so it should be full.

bahn88

· #8 · Mar 21, 2022

Whats the ambient temp there??
If its close to zero a short ride might not give u readings..

kevinmci

Discussion Starter · #9 · Mar 21, 2022

bahn88 said:
Whats the ambient temp there??
If its close to zero a short ride might not give u readings..

The two days I rode the bike around were in the 50-70 degree Fahrenheit range, so relatively warm, but not hot by any means.

bahn88

· #10 · Mar 21, 2022

Ok when mine was giving me issues it read low....hardly moving...then would hit hot...
I put a temp gun on it...all was good..
Did all the checks, replaced the 7v regulator..
Then the issue came back
Fitted a digital meter....always sits steady at 80c now....

Good luck

richnct

· #11 · Mar 21, 2022

The left side chrome water pipe is a handy place to feel the coolant heat up suddenly when the thermostat first opens, letting the hot coolant begin circulating. This should happen a few minutes after starting the bike.

kevinmci

Discussion Starter · #12 · Mar 21, 2022

bahn88 said:
Ok when mine was giving me issues it read low....hardly moving...then would hit hot...
I put a temp gun on it...all was good..
Did all the checks, replaced the 7v regulator..
Then the issue came back
Fitted a digital meter....always sits steady at 80c now....

Good luck

What temps were you getting with the gun? And what digital meter did you put on?

bahn88

· #13 · Mar 21, 2022

Emmissivity is a factor for ir gun readings....
Some guns allow you to change this..
From memory bout 180degrees around the heads..
You will be looking for temperature difference.

I fitted a daytona aquaprova gauge...with its own sender at the thermostat (housing)
Many other members use Koso....

bahn88

· #14 · Mar 21, 2022

Keep in mind...you need to diagnose or rule out issues..b4 fitting the accessory gauge...if its the thermostat for instance...youll still have issues...

murrayf

· #15 · Mar 21, 2022

kevinmci said:
If I understand correctly, the fan kicks on based on the temperature sensor measurement? Is the temperature sensor in the thermostat?

the fan if its a gl or cx500 is mechanical it is running constantly

kevinmci

Discussion Starter · #16 · Mar 21, 2022

murrayf said:
the fan if its a gl or cx500 is mechanical it is running constantly

Thank you Murray, thats what I thought!

Sidecar Bob

· #17 · Mar 21, 2022

To clarify things:

The Thermostat is thermomechanical valve. When the engine is cool it is closed so that coolant moved by the water pump flows through the cylinder heads' water jackets, into the thermostat housing and then has to get back to the pump via the bypass hose. When the engine (& coolant) reaches operating temperature the thermostat's valve opens and coolant can flow into the radiator and from there back to the pump.
An easy way to tell that the thermostat has opened is to feel the water pipe.

The Temperature Gauge Sender is a thermoelectric device that is screwed into the back of the thermostat housing. Its resistance varies depending on the temperature, changing the current that flows through the temperature gauge and thus the position of its needle.

(for reference only - does not apply to 500cc models) The fan switch is another thermoelectric device, this time a basic temperature sensitive switch. It is screwed into the radiator of models that have electric fans to turn the fan on when the coolant temperature reaches 95c and off when it is a few degrees below that.

If your temperature gauge isn't working the first thing to check is whether the wire is plugged onto the sender solidly (it is very easy to bump it and knock it off when you are working on anything under the tank).

Re Haynes: For any thing other than a CX/GL500/650 I would recommend the Haynes as your primary reference source but the Factory Shop Manuals for these bikes are so well written and so well organized that the FSM should be your primary reference and any aftermarket book a secondary reference.
AND it is available for free right away (remember me telling you to download it from the CX Wiki when you first joined?)

Circuit component Motor vehicle Electrical wiring Font Engineering

See less See more

Reactions: 1

kevinmci

Discussion Starter · #18 · Mar 21, 2022

Thank you Bob for your knowledge! That was extremely well written! And don't worry I've had the FSM downloaded since then! I ordered a Haynes just last night to have a physical copy with me in the shop!

Sidecar Bob

· #19 · Mar 21, 2022

A few people have mentioned having the FSM printed at Kinkos or similar services.
BTW, I have a paper copy of the FSM plus both Haynes and Clymer's manuals but I seldom take the aftermarket ones out of the drawer.

Reactions: 1

nolimitz

· #20 · Mar 22, 2022

Sidecar Bob said:
A few people have mentioned having the FSM printed at Kinkos or similar services.
BTW, I have a paper copy of the FSM plus both Haynes and Clymer's manuals but I seldom take the aftermarket ones out of the drawer.

or out from the leg of work bench!

1 - 20 of 20 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.