Fred Rides to the Rescue of One of Our Late-Models Again - But this time, I didn't figure out what's wrong

[moparedtn]

Do you have a good obdII scanner that lets you look at data? See if you can see the engine temp reference change as the car warms up...

I can see that just fine on the cars' own readout on the dash. In A/C mode, the fan operates and the cooling system
returns the car to the preset temperature as normal. The problem is - it doesn't do so otherwise.

Some/many cars have water pumps with plastic impeller blades. The blades break, flow is reduced, and the temperature climbs of course.

Thanks, but this is a straight-up case of the fan not operating when it is supposed to. Everything else is fine.

Trusted shop with modern tools, scanners, etc. Gotta know when to fold em with the modern cars.
Dealers in my area incompetent.

Yeah. Around here though, the dealer is the nearest thing to "reputable".
No, that's not ideal. Is what it is.

Post 19

I'd rather not, thanks, but...
If it does wind up being a situation of "rigging", it'll be with one of those aftermarket controller kits that
operates independently of any need for a manual switch.
I'm betting this situation is not unique to these cars - and therefore, familiar with the dealer wrenches.

 

[Triplegreen500]

I can see that just fine on the cars' own readout on the dash. In A/C mode, the fan operates and the cooling system
returns the car to the preset temperature as normal. The problem is - it doesn't do so otherwise.

But if the gauge has a different sender than the ECM.....you aren't seeing the right data stream.

 

[moparedtn]

But if the gauge has a different sender than the ECM.....you aren't seeing the right data stream.

They are one and the same in this case, at least according to the manual.

 

[moparedtn]

Given that an aftermarket wiring harness with probe and such is only like $50, if the dealer gets grabby -
there are alternatives, especially since the fan itself is only a two-wire affair.

 

[Hey-O]

I'd rather not, thanks, but...
If it does wind up being a situation of "rigging", it'll be with one of those aftermarket controller kits that
operates independently of any need for a manual switch.
I'm betting this situation is not unique to these cars - and therefore, familiar with the dealer wrenches.

I would never suggest rigging your car. Just telling you what your problem is. The fan wasn't your problem.

I'd unrig mine, but it works. Good luck!

 

[moparedtn]

I would never suggest rigging your car. Just telling you what your problem is. The fan wasn't your problem.
I'd unrig mine, but it works. Good luck!

I never suspected the fan itself actually - but I had hoped the ECM wasn't part of the process of
the simple process of energizing it.
Sadly, it turns out it is - and now that the other possible culprits have been eliminated, it appears
the issue lies within the computer (or wiring betwixt).
Since I don't have any manner of either StarScanning the thing (or programming anything), it's beyond
my abilities now...

The process of activating an electric fan as a set temperature is reached has been around for decades
and we know it doesn't require computer power to do such a simple task - but in these rigs, it is anyways.
We'll give the dealer a shot at it and if it's simple enough, they can fix it for us.
If they decide to make bank on the thing however, I'll toss a $50 setup on it that does the job instead
of any computers.

 

[Hey-O]

I never suspected the fan itself actually - but I had hoped the ECM wasn't part of the process of
the simple process of energizing it.
Sadly, it turns out it is - and now that the other possible culprits have been eliminated, it appears
the issue lies within the computer (or wiring betwixt).
Since I don't have any manner of either StarScanning the thing (or programming anything), it's beyond
my abilities now...

The process of activating an electric fan as a set temperature is reached has been around for decades
and we know it doesn't require computer power to do such a simple task - but in these rigs, it is anyways.
We'll give the dealer a shot at it and if it's simple enough, they can fix it for us.
If they decide to make bank on the thing however, I'll toss a $50 setup on it that does the job instead
of any computers.

Every car I've ever built, I've installed electric fans on. One would kick on and then the other when the temperature relay called for more fan. You're right, it's not rocket science. The man that built my car experienced the same problem as you, except opposite. Mine, as I stated, didn't come on automatically when the A/C was switched on, other than that, it comes on at temperature set. He didn't want to spend the money to replace the whole unit either. So, mines been wired like this for over ten years now. You got this, good luck.

 

[moparedtn]

CONCLUSION:
Turns out, I have some crow to eat....
I took the car in to the dealer this morning and told them of what all had been done.
It didn't take them very long (about long enough for me to check out a couple Scat Packs
in the parking lot) to tell me that - get this - the car was functioning as normal.
That means in essence, at least towards the end of my efforts, I was trying to fix something
that wasn't broken.
That said, turns out I probably did wind up fixing something along the way - I just can't tell you
which part did the trick.

At the dealer, I then received an education on this things' cooling system:
The computer turns the fan on and off based on the temperature sensor, of course - as confirmed
by the fan motor relay, mounted in the fan shroud.
The thing is - it does so at different temperatures according to whether or not the a/c circuit is energized.
When the a/c circuit is engaged, it turns the fan on at 203-204F and back off at 194F or so, but when
the a/c is OFF, it turns the low speed cycle of the fan on at about 217F and back off at about 208F.

Now, the day I first noticed the hissing from the leaking coolant cap, I saw the temperature on the dash
showing 217F and my first reaction was "why isn't the damn fan on?", followed by "what the hell is wrong
with the cap/reservoir?"
Those turned out to both be valid concerns...
I replaced the cap, of course (and topped the coolant back off).
I replaced all the relays and fuses and such and when the fan didn't engage when I thought it should have
(by 210F, say) then I fetched the replacement Mopar fan relay/harness and installed it also....
and when it didn't also turn the fan on when I thought it should have, I made the appointment with the dealer.

Well....once it was learned today that it doesn't kick the fan on until about 217-218F, it's obvious that it probably
wasn't turning on the fan when it should (for still unknown, but now replaced reasons); it also got settled that
whatever part I did to fix it did actually cure the issue.
I also found out that those preset temps in the ECU cannot be changed, at least at the dealer level.
I finally talked them into rolling the diagnostic fee into a proper radiator flush and fill, wanting to be done with
the whole affair once and for all...

In the end, I watched it cycle on and off, over and over, until I was satisfied.
Say, anyone in the market for some slightly used (but probably just fine) relays, fuses and fan relay?
(No, I talked the wife out of the $60k Scat Pack. Damn thing was Sublime Green. Yeesh....)

 

[khryslerkid]

We all knew you could do it!

 

[eldubb440]

congrats Ed..... they do like to over complicate things

 

[moparedtn]

We all knew you could do it!

Yeah, whatever it was....thanks.
Oh - I also replaced her center armrest in the car, since the original had formed a crack right where ones' elbow
rests. That's enough time and attention for that car for a while; others await their turn now.

 

[Kern Dog]

CONCLUSION:
Turns out, I have some crow to eat....

Thank you for being considerate enough to respond and explain the conclusion.

 

[moparedtn]

Thank you for being considerate enough to respond and explain the conclusion.

Thanks. It's quite the relief that the situation has been remedied - it is after all "my wife's car" and it's been
a very good one - and since I've been all about seeing to it that I don't leave a mess when I'm gone, her having the car
has been a part of that, since she loves the thing.

 

[Kern Dog]

I mention what I did because some members, primarily new ones, pop in, ask for advice, get a LOT of it and then never return to tell the others if their problem was fixed OR thank anyone that took the time to help.
YOU did that because YOU are not selfish.

 

[moparedtn]

I mention what I did because some members, primarily new ones, pop in, ask for advice, get a LOT of it and then never return to tell the others if their problem was fixed OR thank anyone that took the time to help.
YOU did that because YOU are not selfish.

Thank you my friend. I suppose as we get older, the mind naturally tends towards all things posterity...
You are correct:
If for whatever reason an internet search leads someone in the future to my thread here, I want them to
come away with some manner of resolution to my experience.

 

[Kern Dog]

My build threads are often cluttered with a lot of off topic chatter, much of it my me specifically.
Still, I try to explain my reasoning and do try to in a way, wrap it up/close the book once it is finished.
Ed makes a great point...There will be someone later who may do a search and reads our contributions and gleans some helpful information in a timely manner.
This is just one way to give back to the hobby and our fellow enthusiasts.

 

[moparedtn]

 

[RemCharger]

I had assumed you had it hot enough to trigger the fans as well. But without that info,, it's guessing on prior expectations. Some vehicles won't fire the fan until 225.
Glad to hear it wasn't broken