Brammo Spa Dash Water Temp quesiton (not already asked)

[bolus]

you dont have the grounding problem (temp increases when you turn on your lights), I just like to hear myself type

[silver]

[quote="bolus"]
you dont have the grounding problem (temp increases when you turn on your lights), I just like to hear myself type
[/quote]

haha ok back to my original plan.....do nothing

[DarthChicken]

its not the sensor, its the dash.  I think a more important question may be - where is the ground for the dash, and who has "fixed it", and what were the results?

[silver]

[quote="DarthChicken"]
its not the sensor, its the dash.  I think a more important question may be - where is the ground for the dash, and who has "fixed it", and what were the results?
[/quote]

ok but again I'm going to mention no other display or part of my dash changes or resets or looks like its losing power...........only the WT gauge.

[DarthChicken]

Exactly the same as mine. 

edit:  the ground for the sensor is the sensor itself.  Its a single wire sensor.

[bolus]

[quote="DarthChicken"]
its not the sensor, its the dash.  I think a more important question may be - where is the ground for the dash, and who has "fixed it", and what were the results?
[/quote]

Tom fixed mine doing what ever he did to all my wiring

[silver]

[quote="DarthChicken"]
Exactly the same as mine. 

edit:  the ground for the sensor is the sensor itself.  Its a single wire sensor.
[/quote]


ok my point is how do we know the sensor isn't the problem.....sending weird info to the dash.....making it go to -57

i guess those of you out there that can moitor the WT with and OBDII gauge could answer that question right?

[DarthChicken]

The temp on the OBD-II is not from the same sensor.  There is a water temp sensor on the passenger front of the engine that the ECU uses for running the engine properly.

The sensor the dash uses is the one near the exhaust.

[benyeats]

[quote="DarthChicken"]
The temp on the OBD-II is not from the same sensor.  There is a water temp sensor on the passenger front of the engine that the ECU uses for running the engine properly.

The sensor the dash uses is the one near the exhaust.
[/quote]

Yep most cars have two sensors one for the dash indicator and one for the ECU, always seemed kind of inefficent to me but seems to be a common set up, guess it makes integrating different dashes and ECUs simpler.

Ground for the dash is a small wire on the back of the dash round one of the screws that attaches the back panel of the dash, I don't really think it is good enough although seems to have been ok for me.  Easy upgrade would be to add another couple of wires to the other mounting screws.

Ben

[Terry Kennedy]

[quote="benyeats"]
Yep most cars have two sensors one for the dash indicator and one for the ECU, always seemed kind of inefficent to me but seems to be a common set up, guess it makes integrating different dashes and ECUs simpler.

Ground for the dash is a small wire on the back of the dash round one of the screws that attaches the back panel of the dash, I don't really think it is good enough although seems to have been ok for me.  Easy upgrade would be to add another couple of wires to the other mounting screws.
[/quote]

On mass-production cars a duplicate sensor serves as the "idiot light" in the event of one of the sensors malfunctioning.

The official ground connection on the SPA dash is pin 5 of the main connector. Note that while pin 2 is also ground, it is reserved for the shield of the tach pickup lead:

[img width=425 height=600]http://www.tmk.com/transient/SPA_Dash_Connections.jpg[/img]

[benyeats]

[quote="Terry Kennedy"]
[quote="benyeats"]
Yep most cars have two sensors one for the dash indicator and one for the ECU, always seemed kind of inefficent to me but seems to be a common set up, guess it makes integrating different dashes and ECUs simpler.

Ground for the dash is a small wire on the back of the dash round one of the screws that attaches the back panel of the dash, I don't really think it is good enough although seems to have been ok for me.  Easy upgrade would be to add another couple of wires to the other mounting screws.
[/quote]

On mass-production cars a duplicate sensor serves as the "idiot light" in the event of one of the sensors malfunctioning.

The official ground connection on the SPA dash is pin 5 of the main connector. Note that while pin 2 is also ground, it is reserved for the shield of the tach pickup lead:

[img width=425 height=600]http://www.tmk.com/transient/SPA_Dash_Connections.jpg[/img]
[/quote]

The install on my car has a supplimentary ground provided by the wire I described.  Now I think about it the Pin 2 gnd is probably what was improved when I rewired my car hence the lights / temp interaction going away !

I agree having two sensors provides redundancy, but this technique is not repeated elsewhere in a car's engine, I know coolant is fairly critical but so is oil level for instance.

Ben

[Terry Kennedy]

[quote="benyeats"]
I agree having two sensors provides redundancy, but this technique is not repeated elsewhere in a car's engine, I know coolant is fairly critical but so is oil level for instance.[/quote]

The engine/car doesn't need to monitor oil* - it is happy as long as there is some. On a car with an electric radiator fan (pretty much anything recent), the engine management needs to know the water temperature so it can control the radiator fan.

* Well, except for recent BMWs which have promoted this to an engine management function by removing the dipstick.