troubleshooting car dash gauges

[tmyt]

Hello!,

Im trying to figure out what the problem is with a set of gauges I have, to make it clearer what im working with they are temp/oil/battery/fuel gauges and also a tacho.

http://thumbs2.ebaystatic.com/d/l225/m/mzhTgpZlKyTYn9vnQA8jnOg.jpg

Im trying to get the oil and temp gauges working however they do not respond, I have grounded them and they go up and down so I believe they work.

The tacho works but the needle is way to low, it would be at 500rpm when it should be like 1500rpm.

I have been told that apparently the voltage is regulated from 12v to 5v for the gauges, I have used a multimeter to check this and currently i get 12v to the gauges.

I have attached a few pics to show this supposed regulator, it is an old school piece of metal I think.

Lastly, the fuel gauge has been working to some degree, currently it goes straight to max, like off the chart and I think it was working backwards, the more full the tank, the closer it was to 'low tank' on the gauge. Im not 100% sure if thats the way I remember it tho.

so my question is how do I tell what voltage a regulator is? im not sure if its 5v that is supposed to go around this gauge.

all help greatly appreciated!

 

[Six_Shooter]

I don't recognize what car those are for, but the two pictures attached to your post are of a bi-metal deflection gauge movement. These movements are reliable, but slow to respond to voltage changes.

Knowing what car these are for would help to find a wiring diagram of the car which will verify whether a regulator is present or not. I wouldn't be surprised if there is not one.

If you get full deflection of the gauges when you ground and remove the ground from teh gauge inputs, it's pretty much guaranteed that they work.

 

[tmyt]

its a holden HZ GTS dash. I have had confirmation today that it is definitely regulated 12v to 5v.

http://i779.photobucket.com/albums/yy78/hz_350/20120724_164441.jpg

this is a backside of the gauge cluster. The top left pink wiring is where the 12v is going in.

If i know that its regulated to 5v, in my original posts picture of this bi-metal part, could this be the regulator?

 

[Six_Shooter]

No, what you show above is the gauge movement, it's the part that moves the needle on that particular gauge, other gauges should have similar parts fitted.

I see no regulator in that picture, which also also leads me to believe there is no 5V regulation happening.

Where/how was this voltage regulation "confirmed"?

 

[tmyt]

well, I have been discussing it in this thread, a person posts a picture of how they have replaced the voltage regulator with a different one.

http://forums.justcommodores.com.au...lems-fitting-gts-dash-into-wb-one-tonner.html


and this is a thread from the last year which discussed it

http://www.aussiev8.com.au/holden-v8s/48215-fitting-hz-gts-dash-wb-ute-help-needed-2.html

"The oil pressure, temp and fuel gauges all run off a regulated 5V input - unfortunately the regulator is a silly little bimetal strip with a few wire windings around it and is very delicate (from memory it sits inside the gauge area, you should be able to locate the terminals from the back). Once you find it sometimes just (carefully) tapping it will show a brief response from the gauges as a troubleshooting method. This is a common source of problems for these gauges and the usual fix is to replace it with a solid state regulator, the gauges won't lift quite so quickly initially but they will read more consistently (or read at all if the original regulator isn't working)."

I guess i wanted confirmation that it is definitely a voltage regulator and more info on how to go about installing it. (though I have probably been given enough details in the first thread to begin doing this)

 

[davenn]

its not that simple

from your pics it appears that the resistance wires are wound around metal strips
as current passes through the resistance wire it warms up, this in turn warms up the metal strips which flexes it and thus moving the needle of the gauge

If I am right ... and reasonably certain of that, you cannot change them else the gauge wont work any more

cheers
Dave

 

[davenn]

I deleted your other thread

DONT start multiple threads on the same topic

you already have had your answer .... did you not understand it ?


Dave

 

[tmyt]

Here im talking about the regulator, in the post I just posted I was asking for advice on what the modern resistor equivalent would be for these wire wound resistors.

I thought by creating a new topic I could avoid possible confusion as I discussed a lot of different things in this old thread.

I apologize for my logic, im not as well versed in electronics.

Is it possible then to replace these wire wound resistors with new wire wound resistors?

 

[davenn]

you are still not understanding

as current passes through the resistance wire it warms up, this in turn warms up the metal strips which flexes it and thus moving the needle of the gauge

you cannot replace them they are part of the movement of the gauge

Dave

 

[tmyt]

ok thanks