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temp and fuel gauges

Posted: Tue Jun 05, 2012 5:51 pm
by 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.

Re: temp and fuel gauges

Posted: Tue Jun 05, 2012 5:56 pm
by Scorpma82
Broken wires??
Bad contacts???
have you checked with a 2nd guage (assuming you have one)

Re: temp and fuel gauges

Posted: Tue Jun 05, 2012 6:18 pm
by crystalmeths
I have checked the connections on the dash and the fuel sender and the temperature sensor

Re: temp and fuel gauges

Posted: Tue Jun 05, 2012 6:50 pm
by 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.

Re: temp and fuel gauges

Posted: Tue Jun 05, 2012 7:03 pm
by crystalmeths
thanks superscan do you get replacements at auto electricians ?

Re: temp and fuel gauges

Posted: Tue Jun 05, 2012 7:13 pm
by Scorpma82
What about the circuit board behind the instrument cluster?

Re: temp and fuel gauges

Posted: Tue Jun 05, 2012 7:54 pm
by Superscan811
crystalmeths wrote: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.

Re: temp and fuel gauges

Posted: Tue Jun 05, 2012 8:14 pm
by crystalmeths
thanks again superscan :thumpsup:

Re: temp and fuel gauges

Posted: Thu Jun 07, 2012 12:02 pm
by turbosigma

Re: temp and fuel gauges

Posted: Thu Jun 07, 2012 6:33 pm
by InsaneTD
How can you tell if this is starting to cause trouble?

Re: temp and fuel gauges

Posted: Thu Jun 07, 2012 9:42 pm
by 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

Re: temp and fuel gauges

Posted: Sat Jun 09, 2012 11:37 pm
by 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...

Re: temp and fuel gauges

Posted: Sun Jun 10, 2012 5:58 pm
by crystalmeths
Chriz312 it is shear driver abuse that broke yours

Re: temp and fuel gauges

Posted: Mon Jul 09, 2012 9:38 pm
by 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.
Image


This is a wiring diagram for the dash.
Image


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.

Re: temp and fuel gauges

Posted: Mon Jul 09, 2012 9:56 pm
by 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.

Re: temp and fuel gauges

Posted: Tue Jul 10, 2012 8:46 pm
by crystalmeths
Awesome Scott thanks mate :thumpsup: