2017 Dual cooling fans not engaging at all

[Hank123]

Hello, I would really appreciate experienced advice with this issue: The AC was working fan then it would not blow cold. I noticed the dual fans were working intermittently then stopped entirely. I have replaced the 40-amp fuses and the temp sensor (apparently the 2017 no longer has a relay for the fans). After checking power to the fans which was 12 volts, I replaced the dual fans. I still have zero operation of either or both fans, even when AC is set to LO both front and rear air.

 

[swathdiver]

You're going to need a bi-directional scan tool to diagnose this properly. You can get access to the shop manual's trouble shooting guide at AllDataDIY and maybe charm.ii for free, maybe.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

As mentioned by @swathdiver above, you will get to the root cause of your issue quickly with a quality bi-directional scanner, and not have to revert to the parts cannon, hoping for a solution.

 

[Hank123]

Sadly,

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

As mentioned by @swathdiver above, you will get to the root cause of your issue quickly with a quality bi-directional scanner, and not have to revert to the parts cannon, hoping for a solution.

Thanks for adding me to the forum. I am planning on keeping this Yukon XL despite it having 6.2 Liter and the ridiculous fuel management system. It only has 73k miles on it and is almost new condition.

So, if I keep this Yukon repairs will be on me, as using the dealers anymore quickly gets into cost that stop making sense for keeping these vehicles. I just recently installed new suspension parts front and rear, the dealer wanted north of 9k, I am not easily shocked anymore, and that shocked me. The entire project with the Electronic Stability control struts (OEM compatibility) was less than 2k in parts. So, I am back to upgrading tools again and getting greasy

The issue I am dealing with that brought me to the forum is these dang dual cooling fans. One would think it would be a straightforward repair...HA! Sadly, it's to late regarding the parts cannon you mentioned, that detonation already occurred, and they are still not functioning. So yes, as stated by you and SwathDiver I will have locate a scanner that has more capabilities than mine to diagnose what I thought would be straight forward. ( I guess investing in a good scanner is required if I want to keep this super comfortable formerly dependable beast.

Thanks again I am sure I will be back..

 

[B-train]

Hello, I would really appreciate experienced advice with this issue: The AC was working fan then it would not blow cold. I noticed the dual fans were working intermittently then stopped entirely. I have replaced the 40-amp fuses and the temp sensor (apparently the 2017 no longer has a relay for the fans). After checking power to the fans which was 12 volts, I replaced the dual fans. I still have zero operation of either or both fans, even when AC is set to LO both front and rear air.

The fans won't kick on if the A/C isn't working. You need to address the A/C system first. My guess is you got a leak , lost the freon, and the compressor won't engage.

 

[Doubeleive]

Sadly,



Thanks for adding me to the forum. I am planning on keeping this Yukon XL despite it having 6.2 Liter and the ridiculous fuel management system. It only has 73k miles on it and is almost new condition.

So, if I keep this Yukon repairs will be on me, as using the dealers anymore quickly gets into cost that stop making sense for keeping these vehicles. I just recently installed new suspension parts front and rear, the dealer wanted north of 9k, I am not easily shocked anymore, and that shocked me. The entire project with the Electronic Stability control struts (OEM compatibility) was less than 2k in parts. So, I am back to upgrading tools again and getting greasy

The issue I am dealing with that brought me to the forum is these dang dual cooling fans. One would think it would be a straightforward repair...HA! Sadly, it's to late regarding the parts cannon you mentioned, that detonation already occurred, and they are still not functioning. So yes, as stated by you and SwathDiver I will have locate a scanner that has more capabilities than mine to diagnose what I thought would be straight forward. ( I guess investing in a good scanner is required if I want to keep this super comfortable formerly dependable beast.

Thanks again I am sure I will be back..



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what happens if you do something simple like unplugging the temp sensor? any change?

 

[Joseph Garcia]

Sadly,



Thanks for adding me to the forum. I am planning on keeping this Yukon XL despite it having 6.2 Liter and the ridiculous fuel management system. It only has 73k miles on it and is almost new condition.

So, if I keep this Yukon repairs will be on me, as using the dealers anymore quickly gets into cost that stop making sense for keeping these vehicles. I just recently installed new suspension parts front and rear, the dealer wanted north of 9k, I am not easily shocked anymore, and that shocked me. The entire project with the Electronic Stability control struts (OEM compatibility) was less than 2k in parts. So, I am back to upgrading tools again and getting greasy

The issue I am dealing with that brought me to the forum is these dang dual cooling fans. One would think it would be a straightforward repair...HA! Sadly, it's to late regarding the parts cannon you mentioned, that detonation already occurred, and they are still not functioning. So yes, as stated by you and SwathDiver I will have locate a scanner that has more capabilities than mine to diagnose what I thought would be straight forward. ( I guess investing in a good scanner is required if I want to keep this super comfortable formerly dependable beast.

Thanks again I am sure I will be back..



View attachment 446648View attachment 446649

I am glad that you are listening to our recommendations regarding a quality bi-directional scanner. Add one to your tool box. Autel makes a good one in the neighborhood of $500. Then, you will be able to read ALL trouble codes, along with a brief explanation/pointer to the source of your issue. You will also be able to reset/delete trouble codes, after taking corrective action. You will literally save thousands of dollars in diagnostic and repair costs over the life of your truck, and you will most likely recoup the cost of the scanner within 1 year.