Boeing replied:

Hello Chris, Your mate has a great taste in 4wd's.
He will probably notice to that the fuel gauge will head to full as well. The problem is the sender? that controls both of these. Once this is replaced (it sits behind the main dash where the speedo etc is, the problem is solved. Having said that I have installed one of those radiator prob devices that give off an alarm if no water is detected. Cost about $150 installed but I figured that this was much much cheaper than a new motor if I cooked it. With a problem like this you can get into a false confidence that it is the gauge and not the fact that a hose has broken. I am sure someone more technical than me will know if it is a sender or some other name.

Regards

Mark

Member - Stephen (WA) replied:

I've seen this happen quite a few times on some 75 series in an underground mine I was working at in the early 1990's. Probably twice per week all the guages would move to their maximum levels (including temp and fuel guage) for a couple of minutes and would then drift back down to their proper positions in unison.

Scared the heck out of me the first time it happened as I only "saw" the temp guage. The second time it happened to me I was sitting with the shiftboss and he said it happens occasionally and pointed out all the other guages were up also.

Cheers
Stephen J.

mcgra replied:

hi all

wher do you buy these LWA's from?

gra

Phil G replied:

Chris,

Boeing is on the right track. The temp and fuel gauges get about 6 volt power thru a bimetallic regulator located within the fuel gauge. The contacts stick sometimes, hence your intermittent problem. You need to remove the fuel gauge, and either replace the fuelgauge (which contains the regulator), or touch up the contacts.

Cheers
Phil