Junk fan clutch replacement or something else?

PlumberKev

Original poster
Member
Jun 23, 2020
10
Phx
Hi everyone, long time lurker first time posting. I have a 04 trailblazer ext with 4.2 that was given to us just over 2 years ago so unfortunately I dont know much of the history. The problem is its running hot (230 degrees if I let it) and I think I've got it narrowed down to the EV fan clutch. I've replaced the water pump and thermostat with acdelco, new coolant sensor, flushed radiator, and finally new clutch. The fan clutch was a no name brand which I realize now is not recomended. I believe its working but only for the first 15 minutes of driving. I've done the grab the fan and stop it, checking for a pulse(it does) I can jump the white wire with 12 volts and it engages hard, same with jumping the relay from the 5 to 6 pin I believe. when it starts climbing up in temp it doesnt seem like the clutch is engaged hardly if at all? When I shut the engine off I'll watch the blades and it appears to spin 2 full revolutions, I'll check the blades in 5 mins by spinning by hand and I'll get 1 revolution. If i wait an hour half a revolution as if the cooler it gets the more engaged it becomes. Sooooooo all that explaining to ask is this just a junk fan clutch or do I have a problem with a relay? (swapped 45 and 46 too) Problem with PCM? what other "checks can I do" TIA
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Hi and welcome.

You've done all the right things up to this point. How are you getting this temperature reading? With a scanner or other method of getting live data? If using an ELM327 adapter and Torque, there are custom PIDs you can use to see the commanded and actual fan RPM. I've asked @TJBaker57 for specifics on the custom PIDs to do this.

230 isn't terrible, especially if it's really hot out and running the A/C but according to this chart, the fan should be commanded between 39-56%, which would be fairly noticeable in air movement. Maybe the cheap clutch has a hard time with partial speed commands or fails once it gets hot. The fan running for the first 15 minutes may just be part of the warmup that happens until the silicone gets redistributed in the clutch.

I'd ditch the cheap clutch and go for either a Hayden (our usual go-to) or an ACDelco (pricey). Another option would be to get the much more reliable thermal fan clutch for a 2009 TB and have the codes for the EV clutch tuned out.
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
My question would be, once you notice the temps get uncomfortably high, if you jumper the clutch so it comes on full power, do your temps start to come back down? Do they hold steady, or worse keep climbing.
 

PlumberKev

Original poster
Member
Jun 23, 2020
10
Phx
Thanks for the replies so far. I have a scan tool that allows me to see the coolant temperature but not much more then that. I'll drive it around and watch the temperature and it's within a couple degrees of what the gauge is saying. I don't know about the special adapter but it sounds like it will do more than my scan tool so I'll have to look into that and maybe the thermal clutch is the answer. Yes when I've jumped the clutch after arriving home with high temps, the fully engaged fan cools it back down at a decent pace, I haven't tried it with jumping the relay but I'm assuming it will have the same result.
 

PlumberKev

Original poster
Member
Jun 23, 2020
10
Phx
I guess I should mention that yes it's hot out, daytime temps are nearing 110. All this is being done with the ac running.
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
The ELM adapters can be found for pretty cheap, the ones I've bought for myself, as well as friends/family were never more than $10. The app is designed well and can read a LOT of data. Just have to take the time to setup your displays to show you what you want/need.
 
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TJBaker57

Member
Aug 16, 2015
2,897
Colorado
I'll try to be brief as my cable internet is down and in this remote area that means everyone is on cell service now so that is spotty at best!

If you're a techy sort you can go far with these little Bluetooth elm327 clones. Some will say they don't do much but that is a limit on the users part and/or the software they choose, not the device. I even recently discovered how to command my fan speed to 100% for a short time using just the elm327 and my phone!

I can confirm this current offering works well. Many of these Chinese clones are known to be flaky and all the talk of 'new version' is just BS.





In your current situation a good thing to know would be Commanded Fan Speed vs Actual Fan Speed. The ELM327 adapter can get these with the Torque Pro smartphone app as well as other apps that allow user entered PIDs.

A question: how well is your AC working in that 110 degrees you speak of? In particular how well does it seem to work in traffic, low speed, or stopped in traffic? Have you done or had done any AC service work? Reason I ask is I believe the Fan Speed is supposed to be Commanded higher in response to AC high pressures.
 
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mrrsm

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Oct 22, 2015
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Tampa Bay Area
Some additional potentials for causing "Thermal Over-Soaking" issues to investigate as any of these, all and singly, can overwhelm even a well functioning Electro-Viscous Fan:

(1) Long overdue for a Dexcool Coolant Change AND Radiator Flush.
(2) Clogged Cabin Heater Core.
(3) Clogged, Externally Dirty or Blocked Radiator (Stuck Large Leaves or Plastic-Paper ).
(4) Clogged Transmission Cooler Lines.
(5) Thermostat.
 

PlumberKev

Original poster
Member
Jun 23, 2020
10
Phx
The ac seems to be working ok, not as good as my other vehicle(05yukon) but ok. It's a little hard to judge because before the original clutch was changed the air was not good at all. Turns out on the old one that the fan itself somehow cut a groove into the wiring. So I guess in short sometimes the ac is decent and others not so much. The ac is what got me looking at the fan clutch in the first place, never would have guessed that if it want for finding this site.

The radiator was flushed last week along with a new thermostat and coolant temperature sensor last week but I'll check the other items soon.
 
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TJBaker57

Member
Aug 16, 2015
2,897
Colorado
Well now there's a coincidence, I also have on 05 Yukon. And the Bluetooth elm327 clones will work there also.

You stated the system cooled at a decent pace when the fan clutch was jumped. 'Jumped' would be 100% duty cycle, seldom seen under normal operating conditions. An ugly possibility might be that the fan is operating as designed but the engine is developing more heat than it would under normal conditions. You have already addressed the water pump and thermostat as well as radiator flush and refresh. Are you experiencing any loss of coolant that cannot be seen leaking anywhere?
 
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PlumberKev

Original poster
Member
Jun 23, 2020
10
Phx
I don't believe I'm having any coolant loss, at least I haven't seen any obvious signs. I'll give it a good look over when I get home. Sounds like the ELM327 is a great late father's day present.:celebrate:
 
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Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Apart from high outdoor temps, on thing that does cause some higher than normal coolant temps, all else being equal, is a clogged cat. The tranny could also be throwing extra heat into the radiator. Does it have an aux cooler by any chance? That could also help with temps and also tranny longevity.

Maybe give the radiator and condenser a good flush with a hose. Some have had a bunch of dirt and sand preventing good air flow.
 

PlumberKev

Original poster
Member
Jun 23, 2020
10
Phx
So I ended up checking for coolant leaks and didn't see anything. I took off the radiator cap and noticed white flakes floating. I'll see if I can figure out how to attach a picture. I'm reading it could be from tap water from previous, clear to head gasket problems. Since the TB takes a while to heat up and I can get it to cool back down I'm thinking no on a head gasket problem. To answer other questions, over the weekend I took off the front plastic to expose the radiator, checked for airflow blocks and then used a ac coil cleaner to try and clear any unseen grime.
 

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PlumberKev

Original poster
Member
Jun 23, 2020
10
Phx
So I realize this is a long shot, but is there any way to test the wires and harness that connect to the fan clutch; as in the connection at the fan shroud? I'm wondering if maybe I have a broken wire. I messed around with trying to get voltage readings and continuity but I openly admit I have no clue, even with a wiring chart. Just wanted to try something like that before throwing another clutch at it.
 

mrrsm

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Oct 22, 2015
7,639
Tampa Bay Area
ScannerDanner does an excellent job in this Video of showing How to Investigate the EV Fan Cooling Circuit and functionality test using a High End Scanner Diagnostics, some Back Probing of the Harness per your concerns and provides the EVFC Circuit Wiring Diagram, too:

 

mrrsm

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Oct 22, 2015
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@PlumberKev ... Besides looking to eye-ball the EVCF Harness Repair well conducted in another Thread by @TJBaker57 ... Have a Look at THIS Image as one place that is likely to wear through, with vibration and friction contact occurring between the Individual Wires and the PVC Wire Bundle Protective Tube, such that the wires will eventually Short Circuit each other...Right THERE:

EVFANCLUTCHABRAIDEDWIRE.jpg
 
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TJBaker57

Member
Aug 16, 2015
2,897
Colorado
So for TJ Baker57 how do you get those extra PIDs for the Torque Pro to see fan speed etc.

Right here!! The first two posts detail the parameters to enter in Torque for Fan Speed and Desired Fan Speed.

 

TJBaker57

Member
Aug 16, 2015
2,897
Colorado
So I realize this is a long shot, but is there any way to test the wires and harness that connect to the fan clutch; as in the connection at the fan shroud? I'm wondering if maybe I have a broken wire. I messed around with trying to get voltage readings and continuity but I openly admit I have no clue, even with a wiring chart. Just wanted to try something like that before throwing another clutch at it.

Maybe late to answer this but here is a quick way to check the fan clutch solenoid power circuit for continuity/resistance.
Use a small something or other to probe down into the #4 terminal socket of the Fan Relay/Module. Standard meter test leads are too thick and will damage the fuseblock. Set the meter to resistance and measure from this probe to ground. I am using a frame ground point in the attached image. If you can, use some jumpers to attach the test leads then wiggle all associated wiring leading right down to the fan clutch between the fan blade and the radiator. The reading should remain steady.



IMG_20200704_145913.jpg
 

PlumberKev

Original poster
Member
Jun 23, 2020
10
Phx
Well for some reason I didn't notice all of these suggestions but i might as well post what i tried and did and kinda answer my original question. I messed with the wiring as much as I could think, I even looked into the pcm following a chart from Moose man looking for broken wires and such. I replaced the harness thinking the white wire might be suspect but turns out it's was all fine. I would occasionally get codes so I figured the pcm was working properly. Soooooooo my choices I came up with were replace the clutch again with an expensive EV ac delco or go with a thermal. Even with the ac delco EV I might still need a pcm update so I went with a 08 thermal one(also ac delco). So far it's running great and I can hear how often the clutch comes on and backs off. Now I just got to get the pcm fan patch so I can get rid of the annoying light on the dash. So was it a cheap replacement clutch? Probably. Maybe needed the pcm update? Maybe a combo? I guess I'll really never no but I don't have to worry about it for a long while. Now onto all the other inherited problems.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
For the tune, I recommend @limequat at http://www.lime-swap.com/ . Cheaper than the other guys and just as good. And he can also do other stuff to your tune to "improve" your ride.
 

aaserv

Member
Dec 1, 2019
408
N of Baton Rouge, La.
Im having the same problem and completely forgot I threw in an elcheapo fan clutch a few weeks ago.
Any threads or articles on switching to the 08 thermal ???
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
Any threads or articles on switching to the 08 thermal ???

Only difference between the 2 is thermal doesn't have a wire harness to plug in. You will need to get the code tuned out, otherwise the dash light will be on, since the PCM won't "see" your clutch.
 
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aaserv

Member
Dec 1, 2019
408
N of Baton Rouge, La.
Msgd the guy I got mine from on EBay and hes sending a new 1 no questions asked. Dont even have to return the 1 i have....Now Im wondering if its even worth trying another ElCheapo. I got changing it down pretty good....less than 30 mins but still it obvious he knows they not lasting..
 

aaserv

Member
Dec 1, 2019
408
N of Baton Rouge, La.
Longshot here but cheap enough to try.....Read somewhere about using an electric fan setup from a dodge intrepid. Looked it up and its just about the exact size. Rock has an elcheapo on closeout for $31.. Hayden wiring setup for $21 .... Id probably need the original wiring harness to adapt to but my local u pull has 2 on the lot that i can try getting that from... I realize the fans are probably low quality but if it works i could go with the better models later.. Less than $75 total....Wasting my time or worth a shot???????
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
Wasting my time or worth a shot???????

This, is pretty much what it comes down to.

As long as you don't mind the time lost (as well as the $$$ for stuff you can't return) needing to switch your setup back if things don't turn out the way you hoped, then go for it. I ran a Spal e-fan setup for all of 2 days, before taking it out and going back to stock. Like many have said in numerous threads, there's not much out there that has the air flow of our stock clutch/fan setup, combined with our small sized radiators.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
If you mean replacing the stock clutch fan setup with an electric, no. Been there, done that and got the hot sweaty T-shirt. Barely cooled enough in 30c/85f and A/C performance was poor at idle. I had huge dual electrics from a Montana van that pulled a lot of air. Only ones that were successful with an e-fan conversion were those that also replaced the radiator with a large full aluminum version for a Dodge or TBSS. GM cheaped out on our rads and overcompensated with a huge mechanical clutch fan.
 

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