temp and fuel gauges

[crystalmeths]

hi all both the temperature and fuel gauges have died in my gj , I have replaced the fuel sender unit and the temperature sensor but still not working any help much appreciated thanks Chris.

[Scorpma82]

Broken wires??
Bad contacts???
have you checked with a 2nd guage (assuming you have one)

[crystalmeths]

I have checked the connections on the dash and the fuel sender and the temperature sensor

[Superscan811]

From memory, there is a 10v 3 pin regulator (LM7810) somewhere on the back of the dash.

If it has failed, you lose the Temp and Fuel gauges. These gauges require a regulated voltage to read correctly.


Cheers.

[crystalmeths]

thanks superscan do you get replacements at auto electricians ?

[Scorpma82]

What about the circuit board behind the instrument cluster?

[Superscan811]

thanks superscan do you get replacements at auto electricians ?

Jaycar have the LM7809 (9volt) regulator, you just ad a 1n4004 diode to the ground pin to get 9.7V which is close enough for the gauges to read correctly.
You could also just use the LM7809 but the gauges would be slightly out.

If you need any help with the circuit etc, let me know.


Cheers.

[crystalmeths]

thanks again superscan

[turbosigma]

http://www.ebay.com.au/itm/NEW-5-x-L781 ... 4aa362d7ad

[InsaneTD]

How can you tell if this is starting to cause trouble?

[crystalmeths]

with mine the fuel gauge just stopped working and the temperature gauge started to work only on and off for a couple of days then died

[chriz312]

Could that 3 pin regulator be the same problem for my gh sigma my fuel gauge and temp don't work but I haven't replaced anything yet...

[crystalmeths]

Chriz312 it is shear driver abuse that broke yours

[Superscan811]

Had fun finding my GJ workshop manual.

Here are a few pics.

Here is where the regulator is situated on the back of the dash.



This is a wiring diagram for the dash.



I have located a GJ dash and will confirm the pins are in the same order.

Left to right, looking at the writing on the case, pins facing down.
1=In (12volt)
2= Ground/earth
3=Out (10volt)
Back Plate= Ground/earth.

http://www.fairchildsemi.com/ds/LM/LM7805.pdf

Preferably use a heatsink.

I'll post some more tomorrow.

Cheers.

[81GL]

Hey all.

From memory, these regs are 'clamped' onto the cluster aren't they?
Pretty sure I remember in my GH cleaning the contacts & it all worked fine again??
-A touch and go connection would explain the erratic operation most encounter. Although if both gauges are dead, then likely regulator has failed.

[crystalmeths]

Awesome Scott thanks mate