EGT Pyro Gauge doesn't like new home

[Tim Doumit]

edit: i see this is my first post again... i was a member here a few years ago and i see my post count has went back to "1" so i would like to be the first to welcome me back! hello again everyone!

while swapping over to my new to me 05 CTD from my 96 CTD my autometer pyrometer decided to quit working.

details:
gauge - 2 1/16 phantom
7 years old max
worked perfectly when i took it out of the 12 valve

lights up
needle twitches to ready once when keyed on
does not move otherwise

during the swap i lost a little nut and bolt and solderd the connections leaving the eyes on the probe itself.
tried to keep original length of the yellow 2-wire

probably ****** it off when i dropped his brother "boost" on the floor and knocked his needle off... he got replaced with a 0-60 since he wouldn't have worked anyways. .

the gauges share a common ground and ignition line.
other gauges seem fine.

 

[Prairie Dog]

So you've come crawling back eh? :-laf
Soldering won't give a good enough connection surprisingly. I tried doing that once myself and only the nut/bolt connection was low resistance enough tomake the gauge work. Also the wire is not common copper so you can't shorten it and crimp anther set of lugs on it (requires an industrial crimp machine). Hooking it up any other way other than the way it came will cause it to do what you see. I learned this the hard way after trying to shorten the leads!

 

[Tim Doumit]

uh-oh!
guess ill go find another probe and wire

 

[SierraRam]

The thermocouple uses dis-similar metals, the connectors must be the same metals. When you soldered you now have a incorrect connection due to the tin/lead in the solder. You can cut out the solder joing and buy the correct connectors and heat shrink over them. Remember all of the wiring from the thermocouple to the gage needs to use the correct disimilar wiring. You cant use standard copper wire.

 

[Tim Doumit]

thanks fellas!
i ordered another probe and wire set.
figured seven or eight years on the old one in the 12v was enough.
new (to me) truck, new pyro kit

i will save the old kit to see if i can get it to work. i may drop it into the elbow for a new perspective.