Here's another update for those following this (hello Sparky
)
The week before, we came back from a long 8 day family road trip (as in "National Lampoon's vacation"
). Loaded up the truck with 4 people (~1000 lbs), camping gear, some tools "just in case" and luggage. Even with the rear seats down, it was packed pretty solid. Basically left Ottawa to Montreal, then to Boston that same night, then on to NYC, Washington DC, Gettysburg PA, Scranton PA and then home. Total, just a bit over 3000Km.
A bit of history just before the trip. I finally repaired the A/C. Had to replace the evaporator, which meant removing the entire dash. Not as bad as I thought it would be but still a long process. I also had to replace the radiator and while the system was empty, I finally replaced the radiator push-in probe with a screw-in sensor. Much better control with this one since it's not affected by external temperature. A/C actually works quite well although it could be better at idle but I think this is caused by my blocking off the rear system and leaving the original gold orifice tube. The front only systems use a white one instead. Not a big deal and I'll take it with the heat we were getting. Next time I have to open it up I'll swap it. I also replaced the thermostat and temp sensor (both ACDelco).
We had the A/C running the whole time with outside temperatures usually in the 85-90f with some times at 96f in DC and
very humid. I would keep the fans running at low with the manual override (haven't figured out yet how to hook up the wire so that it won't cycle the fans with the clutch). The engine temperature would be steady at 95-98C. Only when in slow or heavy traffic did the engine temperature climb above 100C (212f). It did climb to about 105C (221f) in DC in 96f temperature and the full speed kicked in from the sensor. When I saw that, I just put the override to full speed because even at speed it wasn't coming down by itself but did with both at full speed. During the whole journey, NEVER did I fear I would overheat.
Now back and just driving around town here with the A/C off and 20~25C outside temps, it works very well. The fans would kick in at low speed when we stop and it reaches the preset (~105C) and has never gone to the high speed without the A/C on. Usually once we get moving for a while, they switch off. Perfect!
I have really good confidence in this setup for the conditions here and probably up to 100f with the A/C on and maybe beyond. GM could have used these if they would have made the radiator just a little bit wider. This controller works well but maybe the other one I saw someone else mention that taps into the stock sensor and PWM control might work with these fans but I don't know. To me, this is sufficient. I will probably try to find or have built some sort of delay system for the A/C feed wire so it doesn't shut down the fans when the clutch cycles off but that will be for later.
Oh, and how did the TB itself fare during the trip? Had a coolant leak caused by the new ACDelco sensor I put in when I replaced it. I guess I didn't want to put it too tight after reading another member having one snap in the block. Was actually easy to fix in a Walmart parking lot. I'd say 30 minutes even removing the alternator! Yay for no more mechanical fan! So easy! And speaking of the alternator, my Remy new alternator I installed a while back held up very well despite the high load of two fans, the A/C and blower, lights (DRL and fogs always on), GPS, DVD, inverter for running the Western Digital Live player. Despite being made in China, it's excellent. Oh, and the other thing that went was the handle for the rear hatch. Had to empty everything out at the campground in Virginia so I could pop it open from inside. Then I McGyvered a cord through the drain hole to pull on the lock release from outside. Other than that, it ran like a top!