Heater Resistor Plug Melting Help!

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simba7
Learner Driver
Posts: 67
Joined: Fri Feb 05, 2010 10:23 pm
Currently Drives:: Renault Megane 1.6 VVT Dynamique 2004

Heater Resistor Plug Melting Help!

Postby simba7 » Mon Mar 26, 2012 9:36 am

Hello everyone,

I really need some help on what to do and the cause of this issue.

My heater recently started being intermittant. Sometimes it would come on and sometimes it would not.

I unplugged the resistor plug going into the motor of the fan underneath the passenger footwell and plugged it back in but to no change.

I then spotted that the plug that powers the resistor which comes from the cars electrical system had a purple wire which was out!

So i pushed it back in and it started working. It was extremely hot to the touch which was very odd and worrying.

I then unclipped the whole plug and had a look and 2 crimp slots were burnt!

I have taken photos of the plug and socket.

Below is the front view of the connector.
https://i43.tinypic.com/35am91x.jpg

Side view of the connector
https://i43.tinypic.com/17r2n6.jpg

The other side of the connector
https://i43.tinypic.com/dbjs6h.jpg

The resistor plug socket - Their is whiteness on the plastic.
https://i39.tinypic.com/1h32gi.jpg

I appreciate any help from anyone who may have had this problem before.

I am not sure what has caused it. It may be the resistor but i cant see how that can cause the plug to melt!

Thanks

longy
Passed Theory
Posts: 31
Joined: Tue Mar 02, 2010 10:56 pm

Re: Heater Resistor Plug Melting Help!

Postby longy » Mon Mar 26, 2012 1:31 pm

HI mate this is exactly what happend to mine dont know what caused it but i changed the resistor for a new one and its been fine ever since,got a new one off ebay for about £38,hope this helps.

simba7
Learner Driver
Posts: 67
Joined: Fri Feb 05, 2010 10:23 pm
Currently Drives:: Renault Megane 1.6 VVT Dynamique 2004

Re: Heater Resistor Plug Melting Help!

Postby simba7 » Mon Mar 26, 2012 3:19 pm

Thanks Longy.

I will change the resistor but I need to change the connector as well now as it is burned and can cause a fire i suppose.

Did you change yours?

Thanks

longy
Passed Theory
Posts: 31
Joined: Tue Mar 02, 2010 10:56 pm

Re: Heater Resistor Plug Melting Help!

Postby longy » Mon Mar 26, 2012 4:17 pm

No mate,i just pluged it back in and its been fine mate.I suppose you could cut the the old one off and graft a new one on from scrap yard.

simba7
Learner Driver
Posts: 67
Joined: Fri Feb 05, 2010 10:23 pm
Currently Drives:: Renault Megane 1.6 VVT Dynamique 2004

Re: Heater Resistor Plug Melting Help!

Postby simba7 » Tue Mar 27, 2012 8:23 am

The thing is it still works when plugged in since i found that loose wire.

Im only worried as to why the connector melted.

Scrappies are charging 45 quid for the cable!

livewire
Passed Theory
Posts: 27
Joined: Thu Jul 12, 2012 4:20 pm
Currently Drives:: Megane mk1 (99)
mk2 (04)
Citroen xsara (02)

Re: Heater Resistor Plug Melting Help!

Postby livewire » Fri Aug 24, 2012 3:58 pm

hello.
just now fixed this.

as the issue is almost always just burning out the 12v supply (yellow) and 4th fan speed (violet) connections.

this can be fixed by cutting these two wires and joining direct to the fan wires.
i used some connecting blocks (choc blocks) which makes a much better connection than the push in blades used in the connector block.
cut the red wire to the fan from the resistor block, cut the yellow at the connector, join these. (as the connector blocks only act as a joint, the feed wire goes from the fuse direct to the fan)
cut the violet at the plug, cut the black wire from resistor block a few inches up, join the 3 wires, so you have 2 blacks and violet. (you need the black from the resistor unit as it supplys the speed settings)

this way removes the connector from the circuit as it appears that it can not handle the full current (at speed 4) and causes it to overheat.

Also took a current reading (at speed 4) which was 14.5 amps. so why have a 30 amp fuse fitted.? fit a 20 amp i would suggest, it might blow before it starts to melt the connector too much!
mine had only melted the connector at the connection for speed 4, no signs on the supply pin which whould had been passing same current? so at a guess it must be the connector rating must be close to the max so it only takes a bad connection,a few years of oxidation, dirty connection for this to start.
Image
Image
Last edited by livewire on Tue Aug 28, 2012 5:22 pm, edited 3 times in total.

longy
Passed Theory
Posts: 31
Joined: Tue Mar 02, 2010 10:56 pm

Re: Heater Resistor Plug Melting Help!

Postby longy » Sat Aug 25, 2012 7:15 am

hi live wire can you post a pic of what you have done please.
ta.

davelowe
Driving Legend
Posts: 3138
Joined: Thu May 10, 2007 3:40 pm

Re: Heater Resistor Plug Melting Help!

Postby davelowe » Mon Aug 27, 2012 10:22 pm

I haven't studied the design of the resistor on the Megane.

What I will say, is that on some cars, the resistor heatsink is in the path of the airflow for cooling purposes. If the vent/filter is blocked, it has been known to overheat the resistor assembly.

Therefore, I offer only the humble advice to check the ducting for an underlying problem.

If I'm wrong, someone will no doubt correct me.
Silver 08 plate 5dr 1.5dci Dynamique 106 Tech Run (re-mapped)

Red 03 plate 5dr 1.9 Dynamique dci120

Best advice for Megane owners: sell it before it bankrupts you!

livewire
Passed Theory
Posts: 27
Joined: Thu Jul 12, 2012 4:20 pm
Currently Drives:: Megane mk1 (99)
mk2 (04)
Citroen xsara (02)

Re: Heater Resistor Plug Melting Help!

Postby livewire » Tue Aug 28, 2012 5:27 pm

longy wrote:hi live wire can you post a pic of what you have done please.
ta.

as requested.
hope it helps others.
saves buying new bits and i think this repair makes it a lot safer.

longy
Passed Theory
Posts: 31
Joined: Tue Mar 02, 2010 10:56 pm

Re: Heater Resistor Plug Melting Help!

Postby longy » Tue Aug 28, 2012 5:46 pm

Cheers mate for the pic. :D

ajsaville
Learner Driver
Posts: 52
Joined: Sat Nov 08, 2008 6:26 pm

Re: Heater Resistor Plug Melting Help!

Postby ajsaville » Tue Oct 30, 2012 9:06 pm

Hi livewire great post :). That's exactly my problem too been under the dash today and renault would like 60 quid for a replacement part with modded cables so they no there is a problem with this wiring loom.

simba7
Learner Driver
Posts: 67
Joined: Fri Feb 05, 2010 10:23 pm
Currently Drives:: Renault Megane 1.6 VVT Dynamique 2004

Re: Heater Resistor Plug Melting Help! *FIXED*

Postby simba7 » Fri Dec 20, 2013 12:18 pm

Hi Guys,

Sorry to be a year late, For some reason i do not get a notification.
I thought i would come back and inform everyone that we fixed the issue ourselves.

We bought a scrap connector from Renault and also a block connector from ebay and literally spliced and screwed the wires into the block.

It now has been running perfectly fine.

Thanks for your help guys.

johnna
Posts: 6
Joined: Mon Dec 16, 2013 7:02 pm
Currently Drives:: Megane 1.5dci

Re: Heater Resistor Plug Melting Help!

Postby johnna » Fri Dec 27, 2013 5:47 pm

This is my next job. One of many jobs on my crappy car...

I'll post updates as I go on.

ozi05
Posts: 2
Joined: Mon Apr 20, 2015 8:59 am
Currently Drives:: Renualt Megane MK2 04 Plate

Re: Heater Resistor Plug Melting Help!

Postby ozi05 » Wed Oct 28, 2015 5:43 pm

Anyone know where i can get the 2 wire red and black wiring loom for the heater resistor? The one with the small green plug that goes into the heater resistor?

livewire
Passed Theory
Posts: 27
Joined: Thu Jul 12, 2012 4:20 pm
Currently Drives:: Megane mk1 (99)
mk2 (04)
Citroen xsara (02)

Re: Heater Resistor Plug Melting Help!

Postby livewire » Wed Oct 28, 2015 7:00 pm

breakers yard? ebay?
a picture would help.
as don't know what wires you mean?


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