I just bought a used TST R49 for my truck with the cool down feature. (4000 Serial Number) However the cool down timer will not work. I've gone over the connections several times, followed the instructions at the website, but it will not keep the engine running. I've tried changing the Timing feature, and the Exhaust Temp, and neither has made a difference. Does anyone have any quick advice on what could be going on?

One note, the tst stays powered on for 10 seconds or so after the key is turned off, but the engine shuts off immediately.

 

I had a problem like this once with a turbo timer i had on a eclipse, i had to find a better ground. not sure if they work the same on these trucks though

 

do you have it set on auto? if so change it.

 

I am totally unimformed here so Maybe indulge my ignorance... But if you have grey keys for the truck could it be the security system shutting off the truck???