Technical Heater - Nerd level help needed

[jrkitching]

@005 taif has just posted about fixing a similar problem on one of the North American 500's:

I have a leak in my evaporator core so I decided it needed changing. To describe this as "challenging" is an understatement to be sure. The amount of parts that need to be removed to get this core out is nothing short of staggering. I believe the very first part they install when building a Fiat 500 is this HVAC unit.

I have attached 2 pictures of what is left behind once the HVAC unit is removed... the throttle and brake pedal and the steering column layed out on the floor. You even have to partially remove both front doors! It took 10 hours to get to the state you see in the second photo. It looks like a Fiat blew up inside my work shop! Parts every where.

Every wire connector is different (almost) and requires solving a new puzzle to disconnect it.

I love my Fiat, but I have to give the engineering of this car a minus grade. Totally ridiculous decisions on how to assemble a car are rampant.

The icing on the cake is the obscene amount of money they want for the replacement core. $468CDN! Cores for other cars are typically $200. There is nothing special about the Fiat core... in fact it's made by Denso.

The instructions from Alldata was a godsend... even though it doesn't describe half of what has to be done to get the HVAC out. There is no mention of the bare steel super structure/cage that surrounds the HVAC.

You've been warned.

The pictures are depressingly similar to those posted by @robinm2000- both reproduced below. Make no mistake, this is a major job - I'd much sooner do an engine change than take this on.

 

[John202020]

Makes my heater matix replacement look a total breeze reckon you could do it in 45 mins now I've done one.

 

[Sparky29]

Hello


My daughter's 61 plate Twinair has just developed the dreaded heater issue. Thing is someone crashed into her in a big Merc SUV two weeks ago. They admitted full liability and the front panel, wing and bonnet were replaced as well as the windscreen under their insurance. When the car was returned the heater wouldn't switch off. I will try hoovering the sensor but is it possible that the actuator arm could have also broken during the impact or would I be wasting my time going back to the insurance company?

 

[John202020]

Hello


My daughter's 61 plate Twinair has just developed the dreaded heater issue. Thing is someone crashed into her in a big Merc SUV two weeks ago. They admitted full liability and the front panel, wing and bonnet were replaced as well as the windscreen under their insurance. When the car was returned the heater wouldn't switch off. I will try hoovering the sensor but is it possible that the actuator arm could have also broken during the impact or would I be wasting my time going back to the insurance company?

Very possible, its worth getting back to the insurance company, issue could be proving it was OK before AND the cost of fixing might write off the car?

 

[Baglady1990]

not sure I could cope if my climate gave out too! with everything else ive had to contend with in one year of owning my 500..... id be tempted to roll her off a cliff

 

[Sparky29]

Thanks. The Crash Repair co say the heater couldn't have been damaged in the accident. I'm incluined to agree but apparently there can be issues with the climate control system if the battery has been disconnected for some time. On older fiats you could reset the system but I can't find any info about whether this is possible on a 500. For future reference though - I found this Youtube clip which seems to offer a simpler solution than the major strip downs that folk have been doing - the proof will be in the pudding though. I'll report back if i get around to this.

 

[John202020]

Thanks. The Crash Repair co say the heater couldn't have been damaged in the accident. I'm incluined to agree but apparently there can be issues with the climate control system if the battery has been disconnected for some time. On older fiats you could reset the system but I can't find any info about whether this is possible on a 500. For future reference though - I found this Youtube clip which seems to offer a simpler solution than the major strip downs that folk have been doing - the proof will be in the pudding though. I'll report back if i get around to this.

There is a actuator recalibration procedure but of temp fluctuates wildly it's unlikely to be this

 

[Sparky29]

It doesn't fluctuate - just gets hot and stays hot. You have to turn the fan to low. Fortunately we only use it for short journeys. Might be worth trying the recal procedure - can you point me to a link, please? Thanks

 

[John202020]

You need, or a friend/member with Multiscan software on a PC to do this.

 

[Sparky29]

Gotcha. Just read the other thread on this. I'm hoping it's not a broken heater flap but will go back to the bodywork people and see if they can help with a multi-scan.

 

[portland_bill]

Gotcha. Just read the other thread on this. I'm hoping it's not a broken heater flap but will go back to the bodywork people and see if they can help with a multi-scan.

Doubtful.

Tell us where you are. We have tomorrow for someone to help, then stuffed for a month. Quite a few people on here with MES.

Did a reset recently on a 500 for a temp display flashing, seems to have worked a treat. Took minutes.

 

[Sparky29]

Thanks. I'm in Lewes.

 

[portland_bill]

Thanks. I'm in Lewes.

Sadly a bit far for me, as I'm in South Oxfordshire.

Look here: https://www.fiatforum.com/multiecuscan-members-register/

Nearest appears to be Southampton, if you're ready for the journey, give him a PM (Private message)

 

[jrkitching]

I'm in Lewes

If you're prepared to drive to the Southampton area, give the guys at small car services a call.

If it is the usual problem, they've developed an affordable fix. Scroll down their homepage for details.

 

[szamat2012a]

@005 taif has just posted about fixing a similar problem on one of the North American 500's:

I have a leak in my evaporator core so I decided it needed changing. To describe this as "challenging" is an understatement to be sure. The amount of parts that need to be removed to get this core out is nothing short of staggering. I believe the very first part they install when building a Fiat 500 is this HVAC unit.

I have attached 2 pictures of what is left behind once the HVAC unit is removed... the throttle and brake pedal and the steering column layed out on the floor. You even have to partially remove both front doors! It took 10 hours to get to the state you see in the second photo. It looks like a Fiat blew up inside my work shop! Parts every where.

Every wire connector is different (almost) and requires solving a new puzzle to disconnect it.

I love my Fiat, but I have to give the engineering of this car a minus grade. Totally ridiculous decisions on how to assemble a car are rampant.

The icing on the cake is the obscene amount of money they want for the replacement core. $468CDN! Cores for other cars are typically $200. There is nothing special about the Fiat core... in fact it's made by Denso.

The instructions from Alldata was a godsend... even though it doesn't describe half of what has to be done to get the HVAC out. There is no mention of the bare steel super structure/cage that surrounds the HVAC.

You've been warned.

The pictures are depressingly similar to those posted by @robinm2000- both reproduced below. Make no mistake, this is a major job - I'd much sooner do an engine change than take this on.

Hi! In my car, only the air recirculation actuator has failed. It moves the flap, but afterward it keeps making a continuous clicking/grinding noise.

Without removing the dashboard/IP, how can I remove just the air recirculation actuator? I’ve already removed one of the screws, but the others are almost impossible to reach.
Or is it possible to unbolt the entire recirculation box and somehow take it out?

Thanks! M

 

[The Panda Nut]

Thanks for replying - actually the part that is broken I believe is called the blend door or flap door. The door is in inside the heater unit and there is about 2cm of plastic that peeps out the side of the housing that is turned by an actuator motor on the right hand side of the unit (as the driver looks at it).My problem was the heater only blows cold, on inspection the end of the blend door had sheared off. Obviously a dodgy moulding or brittle plastic. I cannot work out how to repair the blend door. Glue would just break off again I would have to somehow drill and pin it. which seems impossible unless I start unbolting the heater housing. I am guess If the fixing points are the same and the loom is the same it will fit (and work) but I don't know if there are ay significant differences.

may be worth experimenting with Easifix glue. Its staggeringly strong on car plastics.

 

[John202020]

Hi! In my car, only the air recirculation actuator has failed. It moves the flap, but afterward it keeps making a continuous clicking/grinding noise.

Without removing the dashboard/IP, how can I remove just the air recirculation actuator? I’ve already removed one of the screws, but the others are almost impossible to reach.
Or is it possible to unbolt the entire recirculation box and somehow take it out?

Thanks! M

If you can keep the flap in "air from outside " mode then simply disconnect the actuator, make sure the ac if fitted works!

 

[steveras57]

not sure I could cope if my climate gave out too! with everything else ive had to contend with in one year of owning my 500..... id be tempted to roll her off a cliff

And on the plus side you get a day out at the seaside and fish and chips sounds like your weakening a bit! drink some concreate and harden up!!!- as you have replaced half of your car now your more than half-way to "perfection" put that towel away now!

 

[A3jeroen]

Remember the screws are (like everything else on the heater box) 5,5 mm. I had to change the actuator on my direction flap (climate control) and this was on the left side. I think the recirculate flap is on the other side.

gr J