The thermotime switch grounds through the pump, then engine block, then ground strap. It receives +12V when cranking via the starter solenoid (red/white wire). Teflon tape is unnecessary. One of the vendors once told me that if you look at the switch and you see that brown colored dot on the side of it, and the dot is cracked, discolored, or damaged, then the switch should be replaced. Check to make sure the electrical plug is OK and also use a meter to verify +12 at cranking when the engine is stone cold. I think it should have power for something like 8 seconds? Andy -----Original Message----- From: Derek <derek.grozio@xxxxxxxxxxx> To: dmcnews@xxxxxxxxxxxxxxx Sent: Mon, 26 Jun 2006 03:41:03 -0000 Subject: [DML] How does the thermotime switch work? I recently did a valley of death teardown and now the car seems to have problems starting when cold. The only thing I really touched thats involved in the hot/cold start circuit from what I can tell is the thermotime switch. I removed it from my old water pump and replaced it in the new one. My question is, does the switch threads use the water pump as a ground? I put teflon tape around the threads before reinstalling. This is my only idea so far, as I do not know how this circuit works (what is being sent and triggered by the switch) and haven't pulled out the multimeter yet to check it. Any comments are appreciated, thanks. -Derek #10084 To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/