Recently converted to factory 05' e fans and pinned the PCM wiring harness. I have a question about where everybody is having their fans commanded on at.

Just a little bit of info about the tune I currently have. First I'm a novice at best so don't beat me up too bad. I'm using efi live. I got a factory 2005 tune from tune file depot and took a pic of the factory fan part of the tune and made my 03' tune match it. My concern is that the factory tune has the low speed fan kicking on at 226.4f. Maybe it's me but this seems quite high. I'm not 100% confident in this but I know that "if" the tune I downloaded was in fact a factory tune and this is how gm wrote it for trucks they had to warranty power train for 5/100k surely they know better than I do.

I was able to get the fans to come on when the ac was turned on

I was able to command the fans on using efi live

I was able to get the low speed fan to come on when I finally got Ect over 226f.

I know everything is wired and working properly but I can't seem to get over that high low speed fan turn on temp.

What's everybody else doing in regards to their fan on and off temps? Is anyone changing the turn on and off ac pressures?

 

The more the fans run, the more the electrical motors will wear.

Unless you change the T-Stat to a cooler temp you won't gain too much by having them come on sooner.





Factory Fan settings from a 2006 Silverado

 

I always put in about 45sec delay on the fan 2. That way the fans are allready on 1/2 speed when the 2nd pin (high) is commanded. It is alot easier on relays. The amp draw in those fan from a complete stop to high is huge and wears out relays.

 

Well thanks for one for the quick replies! I believe those are the same fan specs from the 2005 file I copied them from.

Second I appreciate the input and may try the 45 second delay deal.

I just couldn't get over the high (factory set) cut on temp. I had an on vho that would never move off 210 once it was warmed up.

I think I either have a bad thermostat or something else is going on because driving down the highway at 75 this sucker will get up to 210 on the gauge and then drop to like 160 and hover around 180 cruising without the PCM commandiing the fans on at all. Before with the factory clutch fan it would stay rock steady at 210 once it got there. I think I have some more trouble shooting to do but at least whatever is going on is causing this thing to run cooler and not hotter.

My first thought was that I went to a larger radiator with more cooling area and maybe why it is cooling off so well.

But the thermostat should control that I would think, but I never touched the thermostat. All I did was run the wiring, install 34" radiator, new hoses and fans, copy fan specs from 2005 file and tune it. Coolant level is full and the fans seem to work as designed when the PCM commands them on. Idk maybe it's coincidence the thermostat was have taken a dump at the same time I replaced everything. It has happened before.

All in all I'm over the factory fan settings now I have a bigger fish to fry. I'll probably change the thermostat out tonight if for nothing else just as a preventive repair and quit being so cheap

 

I brought mine down and run the stock 186 degree thermostat. I couldn't be bothered with the factory settings GM has..... and no my fans do not run all the time either.

 

yeah, turning on the fans at 226 is rubbish.

Also, if you're going off the gauge on the cluster for temp it's not accurate.

I've got my fan #1 coming on at 184 now and fan #2 at 194.

When I was boosted, I kept the ECTs in the 170s under boost. Now that I'm n/a it doesn't really matter anymore.

 

That 226* turn on is indeed a factory spec. GM has been doing that for well over 20 years on its fuel injected V8s

 

i think mine come on at 190. i have a 160 stat and i sit between 170-180*

 

Ok so I know my 05 Yukon XL 5.3 is not meant for towing but I started towing with it anyway. It got a little warm the first time so I installed a new water pump, low temp thermostat, and an all aluminum radiator for the 6.0 engines. Now my truck won’t warm up if it is driving and the fans don’t turn on until after it gets hotter than half way. Truck runs great but the fans not turning on until after half concerns me considering engines are brutally expensive right now. Where would I get my PCM tuned to engage fans sooner? I had Efans from factory

 

"hotter than halfway" about what temp is halfway?

This is what it looks like in HP Tuners (actually the cut on temps have been lowered)