2008 Kenworth T660

i had a problem with low coolant alarm couple months ago and went to a local repair shop to see what is going on. coolant level were where it should be and the alarm with low coolant and check eng, would not go away was annoying puzzler, so they did something to shut it off, a week ago i found out there is no alarm sound in my truck at all, so i went back to the shop and ask what they did and if they can reverse and the owner of the shop told me that there was a guy who worked on my truck and that guy is no longer with the shop and they cannot know what he did at that time, so i thought owner want to scam some more money out of me in short i think they unplug something from the puzzler or the alarm speaker it self, so could someone please be kind to point me where that puzzler on 2008 KW T660 located at. so i can look at it and see before i pay these guys again if its something i can do my self....... thank you in advance and any help would be appreciated