pyrometer problems

[G_loomis]

I have installed an 'autometer' pyro in the my truck for obvious reasons...but since I have never dealt with one of them before, I think I am about to ask a somewhat stoopid question.

I took it for a drive for about 20mins, nothing hard, but one or two steep, long inclines and the temp didnt move. I thought exhaust temp would increase pretty quickly once things got moving.

But then I noticed when I got home that when the car is turned off, the gauge temp needle sits below zero (which one would expect)...but when I turn the power on, the needle goes even further south.

So according to the pyro my exhaust temp NEVER got over 0 degrees in 20 minutes of driving...I have just double checked all wiring and all is sweet.

Something is obviously wrong here...but I cant figure out what?!

HELP






Please


EDIT : Just checked the probe part which goes into the dump pipe...about the first inch of it is sooted up.

[Chucky]

Have you got the power polarity correct.
When you put power to it the gauge shouldn't go down.
Or maybe the cables from the probe to gauge is backwards

[GUEEY]

Probe ( Thermocouple) is wired the wrong polarity.
reverse the connections on the back of the gauge.

Grant

[G_loomis]

its not a polarity problem...I have double checked and all is good...I even switched them in case they "the factory" stuffed up...but no change.

I did however discover that if I take the thermocouple out of the dump-pipe it works fine...as soon as the fittings touch the dump-pipe it seems to earth out. Yet I am using all the supplied fittings.

what could be causing this?

[not not]

GLoomis my bet is the thermo coupler that goes in the dump is to far in and earthing out on the inside of the dump pipe Pull it back somewhat and all should be fine! Hence do not push the prob all the way in. Let us know how ya get on! Cheers jamie

[G_loomis]

GLoomis my bet is the thermo coupler that goes in the dump is to far in and earthing out on the inside of the dump pipe Pull it back somewhat and all should be fine! Hence do not push the prob all the way in. Let us know how ya get on! Cheers jamie

I will have a look in the morning, but I am pretty sure that isnt the reason...mainly because the thermo coupler goes into the dump pipe at the bend...in other words the end of the thermo coupler is going down the vertical part of the dump pipe.

But I will let you know.

[G_loomis]

Checked that out when I was at Dales this morning not not....and that is not not the problem

Though I have found out what is...there must be a broken connection on the thermo coupling...cause there is power running through the neg wire. So back to autobarn and get a replacement.