09 Yukon Intermittent fan e-fans not running

[olliec420]

So the other day I went out and the a/c kept turning itself off. It was nice out so I put down the windows and was going to look at it later. Im about to get to the store sitting at a light and I notice the temp is over 210 (where it normally sits). I turned the heater on and when I started moving the temp went down. At this point I knew it was the fans. I stopped in the parking look and looked and sure enough no fans. Fuses ok. Headed to a friends with heat on and windows down. Looked at it for bit and shut it down. Hung out for a while, reseated the relays. Started it back up and they were working so I went home. Started it this morning and they weren't working so I headed to auto zone to get a relay (fan control relay). They started working on the way, I know this because the A/C came on and stayed on. Someone on reddit told me the system will shut down the a/c if the fans aren't turning when they should.

Thinking back, there was a time over the winter when it a/c wouldn't start and I wasn't really worried about it because it was super cold out so I had the heater on anyway. I didn't notice any rise in coolant temperature then. But this tells me it is an intermittent issue that started while ago and now is much more frequent.

Anyhow, today I got the relay and put it in and they didn't seem to start right away. We tapped on one and it started and then tapped on the other and it started. Could that be coincidence? I dont know. I tried that again and one started and one didn't. Is there a time delay before they come on when starting up, even when engine already hot? Could it not be the relay but the fan assembly itself? What are the chances of both fans crapping out at the same time? Oh yeah, 160k miles. I dont mine getting new fan assembly, I just need to be sure that is going to be the fix. Anyone had this problem?

 

[Doubeleive]

So the other day I went out and the a/c kept turning itself off. It was nice out so I put down the windows and was going to look at it later. Im about to get to the store sitting at a light and I notice the temp is over 210 (where it normally sits). I turned the heater on and when I started moving the temp went down. At this point I knew it was the fans. I stopped in the parking look and looked and sure enough no fans. Fuses ok. Headed to a friends with heat on and windows down. Looked at it for bit and shut it down. Hung out for a while, reseated the relays. Started it back up and they were working so I went home. Started it this morning and they weren't working so I headed to auto zone to get a relay (fan control relay). They started working on the way, I know this because the A/C came on and stayed on. Someone on reddit told me the system will shut down the a/c if the fans aren't turning when they should.

Thinking back, there was a time over the winter when it a/c wouldn't start and I wasn't really worried about it because it was super cold out so I had the heater on anyway. I didn't notice any rise in coolant temperature then. But this tells me it is an intermittent issue that started while ago and now is much more frequent.

Anyhow, today I got the relay and put it in and they didn't seem to start right away. We tapped on one and it started and then tapped on the other and it started. Could that be coincidence? I dont know. I tried that again and one started and one didn't. Is there a time delay before they come on when starting up, even when engine already hot? Could it not be the relay but the fan assembly itself? What are the chances of both fans crapping out at the same time? Oh yeah, 160k miles. I dont mine getting new fan assembly, I just need to be sure that is going to be the fix. Anyone had this problem?

I would be checking the temperature sensor/sending unit, a issue with the fans/relays being bad would be very rare. after the temp sensor the next suspect would be the pcm or pcm wire harness, water intrusion can cause corrosion and bad connections.

 

[olliec420]

I would be checking the temperature sensor/sending unit, a issue with the fans/relays being bad would be very rare. after the temp sensor the next suspect would be the pcm or pcm wire harness, water intrusion can cause corrosion and bad connections.

From reading in another thread I understand that if they sensor wasn't working, it would be fans on full and a/c off. I got no fans and a/c off. Actually that may be a better title for this post.

 

[Doubeleive]

I would hook a tech2 or other similar tool to it then and see what is going on, i.e. what is the temp it is reading and what being command or not commanded, etc.
check the pcm harness it's fairly common for things like this to be caused by poor connections

 

[olliec420]

It has to be the fans, today again, they come on when I slap them. Several videos on YouTube about fans going out. Got upgrades ones coming from Summit. Will swap and report back.

Also while I was scanning it (I have iCarsoft i900 scanner) I noticed the ambient temp sensor was stuck 64.4 and it was well over 70 out. I don't know if its broke or needs calibrating some how. A new sensor is $8 so I'd assume replace it. No other codes or anomalies that I could detect.

 

[swathdiver]

There are 3 relays for the fans. The fan motors are the 500 watt variety for an XFE. You need a Tech-2 to properly diagnose this.

 

[Doubeleive]

It has to be the fans, today again, they come on when I slap them. Several videos on YouTube about fans going out. Got upgrades ones coming from Summit. Will swap and report back.

Also while I was scanning it (I have iCarsoft i900 scanner) I noticed the ambient temp sensor was stuck 64.4 and it was well over 70 out. I don't know if its broke or needs calibrating some how. A new sensor is $8 so I'd assume replace it. No other codes or anomalies that I could detect.

are the fans on there now original? or some aftermarket?

 

[olliec420]

are the fans on there now original? or some aftermarket?

Originals. It’s definitely the fans. Both of them too. It can’t be coincidence at this point how many times they and the a/c don’t run unless I open the hood and physically smack them and they start and everything works. I don’t know when that ambient temp sensor quit but that’s getting replaced too considering the low cost of the part.

 

[Doubeleive]

Originals. It’s definitely the fans. Both of them too. It can’t be coincidence at this point how many times they and the a/c don’t run unless I open the hood and physically smack them and they start and everything works. I don’t know when that ambient temp sensor quit but that’s getting replaced too considering the low cost of the part.

hmm first I have heard of the oem fan motors failing, have you pulled the connectors off and inspected the wiring harness at the fans? there was a recall for the harness melting and potentially causing a fire hazard.

 

[mattbta]

lsxmatt has a youtube about having to replace the fan motors after running his e-fan swap for some length of time. had oem fans that were of unknown usage and replaced with oem motors.

 

[olliec420]

There are a lot of videos on youtube of people changing this fan assembly out for a new one. I see electric motors in fans and other applications a lot and in the same type fashion. Intermittent start but help it spin or tap/slap it and it will start. Here is the video I used for installation instructions, he's having same symptoms. Overheating, no a/c, no fans.

I have checked the connections, they tight and don't look bad. And also that wouldn't explain why it starts fine when I give it a smack.

This is what I ordered, 9 and 7 blade from 7 and 5. Who knows if that makes a difference but it was priced nice on Summit, was like 70 more on amazon and eBay. https://www.summitracing.com/parts/FSS-76016

 

[Doubeleive]

There are a lot of videos on youtube of people changing this fan assembly out for a new one. I see electric motors in fans and other applications a lot and in the same type fashion. Intermittent start but help it spin or tap/slap it and it will start. Here is the video I used for installation instructions, he's having same symptoms. Overheating, no a/c, no fans.

I have checked the connections, they tight and don't look bad. And also that wouldn't explain why it starts fine when I give it a smack.

This is what I ordered, 9 and 7 blade from 7 and 5. Who knows if that makes a difference but it was priced nice on Summit, was like 70 more on amazon and eBay. https://www.summitracing.com/parts/FSS-76016

we have gone over and over on fans on the forum for years, you are the 1st that I know of to report such a problem, guess there is time for everything to happen.
the only other thing I can think of that would cause the fans to not spin up properly beside simply being bad is from not enough amps.
if you still have the same issue after replacing the fans that would be one thing to check.
I did upgrade mine from the 500w oem to the 750w oem and when I did that I put in brand new motors simply because it made sense not because of any known issue with them failing I bought the shroud used out of a hummer and just had no idea how much they had been used.
in his video it looks like he put in tyc I wouldn't recommend them myself I have read to many reviews of them failing.

 

[olliec420]

New fans in, problem solved. Much more air moving!!

 

[swathdiver]

New fans in, problem solved. Much more air moving!!

What kind did you replace the old ones with?

 

[olliec420]

What kind did you replace the old ones with?

Pardon Our Interruption

 

[swathdiver]

Pardon Our Interruption

Thanks! Were you able to tell what wattage the fan motors are?

 

[olliec420]

Thanks! Were you able to tell what wattage the fan motors are?

No, but it said 6.2, 5.3 so I figured that was good enough.

 

[swathdiver]

No, but it said 6.2, 5.3 so I figured that was good enough.

That's is true, especially for your cool XFE. What kind of gas mileage do you get city and highway with it?

 

[olliec420]

That's is true, especially for your cool XFE. What kind of gas mileage do you get city and highway with it?

After you asked about the wattage I got worried and tried to go check. All it says is drop in replacement for factory with factory wiring connections. No mention of wattage.

Yes, my xfe... so I’ve been meaning to do a blog on this but I’ve been so busy and just needed to get everything done so fast I couldn’t plan videos... I am the first and third owner of this xfe. I bought it new in 09 and traded it in and a guy that worked near me bought it. I told him it was mine and etc etc and that I wanted it back after a couple years. Well last August he called and said he was getting a new one and did I still want it. I told him yes and bought it with the intention of making it a hot rod. I had a 21 Sierra. Well three weeks after I bought it, I got hit in the Sierra. And it took them 3 months to fix. So the XFE Yukon became by primary when I had no intention of that and after only having new cars since 06, needless to say it was kinda a shock. I got the Sierra back and it wasn’t right, something was up in the steering and they wanted to change the frame out to fix it and that was going to take months. The dealership bought out my lease for me. So now I got the XFE as main and bought a 98 from a guy on Craigslist. It’s the secondary now.

So back to your question after all that you didn’t ask for lol... the lifetime average mpg on the computer says 16.1. When it was new I did strictly in town driving and I don’t remember a number but I feel like it was better than 16.1 but maybe wrong. It has the LC9 engine with the oil problems and had all the Pcv, pistons, rings and bearings redone at 45000 under warranty. 156k on it now. I guess if the engine goes I’ll get a ~450hp built 5.3 and put in. I’m slowly trying to get it mint condition. The guy who had it didn’t baby it. He had kids and dogs and hunted with it so it was off road a bunch. Finding suspension parts has been tricky because of the xfe. I had a local shop do struts on it and first time they used regular ones and it was a bit squatted so I took it back and they said they re did it with the right ones. It’s been interesting and I’m sure it will get more so as time goes on!

 

[swathdiver]

Thanks for the report. After learning that they existed I did a lot of research on them. Figured a 2010 would be good for my wife as they had ventilated seats and the engines received VVT for even better fuel economy. Then she drove a 6.2 and wants something faster!

Pleased with my LC9, took it to the drags again last night. It's no rocket ship hauling 6350 pounds around but racing is still racing.