2004 Chevy Silverado EC 1500 5.3L LT3 over 350kmiles. Passenger heated seat started getting wonky about a year ago. Local dealer thought it was the seating elements going out...so we replaced them a month ago. Still acting wonky...but hard to track down the problem. Wonk Factor: Heat will work fine for an hour...and then quit. Hit the button to restart and maybe it works for another 15 minutes. Hit it again and the light flashes and goes right back off. This will happen several times untill I get tired of pushing buttons. Took it back to the dealer and they "can't reproduce the issue". It worked fine all day yesterday. Today...back to full wonk mode. But. Learned something new. IF no one is sitting in the seat...it will work perfectly and stay on. It appears to only malfunction if someone is sitting in the seat. :hDealer wonders if it's a grounding issue...maybe it thinks it's shorting out and quits..but maybe it's grounding out instead. To be fair...this truck has been known to exhibit some passive aggressive tendencies at times. I'm "Driver 1" and it will forget my settings. It never forgets DH's "Driver 2" settings...and has been known to toss some of D2 info onto D1. His country stations kick my classical to the curb. It's a puzzle. Anyone ever see this before? The seats..DH is probably messing with my settings!;)CTS

My first thought is way too many FREDs

JRscooby wrote:My first thought is way too many FREDsOk...I'll bite. FREDs????

It's the heated seat controller in the door panel just above the window controls. I had very similar erratic behavior in my wife's 2003 Yukon XL. The problem is the plastic joints aren't fully sealed and moisture gets past the seal on the window and drips onto the unit. Over time water gets in and corrodes the solder joints causing odd short circuits.Get a new seat controller (About $200) and before you install it, use 100% and cover all the joints in the body of the module.KJ

My Malibu seats started to get a mind of their own, replacing the old battery restored its common sense. A quick dip in voltage gives these systems a brain freeze.

Maybe the seat warmers know its july in Missouri and they shouldnt be working that much?

Mechanical Mystery... | Good Sam Community

Grit_dog
Navigator
Aug 02, 2020
time2roll wrote:
dodge guy wrote:
BTW, there can be 10-50 even 70 modulates in a car depending on what kind of car it is and trim level!
This is part of the revolution that Tesla is changing in the automotive world. All these control modules are consolidated into the main computer where programming can be better integrated and even upgraded as needed with no dealer visit.

Who the f cares?
Don’t you guys ever get tired of jerking off Elon Musk?
This thread is about someone on a budget with their old pickup truck....
time2roll
Nomad
Aug 01, 2020
dodge guy wrote:
BTW, there can be 10-50 even 70 modulates in a car depending on what kind of car it is and trim level!
This is part of the revolution that Tesla is changing in the automotive world. All these control modules are consolidated into the main computer where programming can be better integrated and even upgraded as needed with no dealer visit.
Grit_dog
Navigator
Aug 01, 2020
^ How far back? Lol
Well 90s will have less electronics than 2000s and 80s less than that, and so on.
You are 1000% missing the point. Stuff wears out.
Going back in time will just give you a different set of headaches and good luck with power seas and seat heaters in a pickup, lol.
I have an 86 Chevy 3/4 ton. Last year before there were any computers, to speak of.
It has power windows (new), cruise/int wipers (new mf stalk), AC (rebuilt) and everything works, but everything requires work on it. It’s OLD.

I’d say this is amusing, but can tell that you’re concerned about these things and for that I am empathetic. But newer vehicle, lower miles = better. That is what you need to know.
covetsthesun
Explorer
Aug 01, 2020
How far back do you have to go to get away from so much computer stuff? I'd still like power seats. Had an Equinox loaner with manual seats....need to see the chiropractor now LOL!
covetsthesun
Explorer
Aug 01, 2020
Well...this truck isn't exactly a spring chicken. 2004 with 350k plus miles. The new control head on the ac is apparently working. The mechanic is hoping it's the last one...but..he's getting quite an education.

We will get a newer vehicle...but oh boy so many more bells and whistles to go wrong.

Ben... I see you have vehicles going back to 1980! Wowza! cts
BenK
Explorer
Aug 01, 2020
When these highly integrated computer controlled systems work, they are wonderful...until any 'one' thing becomes marginal

Then the whole system can flake out and most mechanics just change out components and sub-systems...until the cost is so high as Kevin states and/or they create even more problems so they go in circles trying to find whatever it is

Sometimes it is best if the offending component or sub-system completely fails and they fix it before that takes down other components or sub-systems

One reason I'm not in a hurry to get another newer TV
Grit_dog
Navigator
Aug 01, 2020
CTS, you’re chasing dimes and tripping over dollars. Step back and re assess unless you just like bowing money.
BTW, control head isn’t an actual part. Although it could be the control module for the hvac
It pains me to see this, as you seem like nice people who don’t know much about cars. You’re digging aN expensive hole with this truck.
It’s done, move on.
If all this stuff didn’t fail, old cars with a gazillion miles would be worth more. This is why they’re not.
dodge_guy
Explorer II
Aug 01, 2020
This is what makes some newer car get totaled. They becom to expensive to repair. Trying to diagnose it alone would make them not worth repairing. I've seen perfectly good running cars sent to the junk yard because there was an issue that cost more to fix than the car was worth.

BTW, there can be 10-50 even 70 modulates in a car depending on what kind of car it is and trim level!
covetsthesun
Explorer
Aug 01, 2020
Mystery deepens... Check engine light came on. And the seat warmer worked for a full day. Dealer cleared the code and the seat quit working. Code was for an O2 sensor. Then the AC which had been frosty cold suddenly quite working. Blower worked...but no cool air. Not hot..just not cool. Back to the dealer. A "control head" was determined to be the problem. But. The new CH only got the drivers side to work untill it was "reprogrammed".

Control Heads...Control Modules...out of curiosity, how many of these things are lurking in a 2004 truck? Could it be that all of these "controllers" are failing? cts
covetsthesun
Explorer
Jul 25, 2020
campigloo wrote:
covetsthesun wrote:
It's 68 degrees this morning here... and a seat warmer feels good on old bones. I've used the heated seats nearly year round...except on 90 degree days. The truck battery was replaced around 18 months ago. The passenger seat elements had been playing games for a year before being replaced a month ago. The new ones are doing the same thing, so it shouldn't be the problem. I'm going to have mech check pull the switch and look for corrosion. The dealer is concerned with a ground wire problem.
Any other ideas I can give them? cts

Man 68 sounds nice. We weren’t able to evacuate this year. Our mornings are 78-&2. Enjoy!!!!

Oh I do enjoy the cooler mornings! It's 85 right now and the humidity is darn near 100%! You'd be right at home!:B

Forum Discussion

Mechanical Mystery...

About Travel Trailer Group

Related Content

Mystery Bump

Mystery leak

Toilet Mystery

Mysterious Propane "Leak"

Mystery Switch