Diagnosing a faulty heater resistor pack

[a.jenkin]

I’m pretty sure my heater resistor pack is knackered as I have no fans working. Before splashing out to buy a new one, I wanted to be certain that this is the problem.

I have been trying to follow some instructions I found on the net without much success:

http://www.fixya.com/cars/t1137252-renault_clio_sport_182_air_con_fan

Basically I disconnected the connectors from the resistor pack and the blower unit to test voltages and continuity on the connectors.

On the connector for the blower unit, I could only find 1 6.5v feed on track 1, and 2 earths.

On the connector for the resistor pack, none of the 1-5 tracks appeared to be supplying a voltage.

I performed these tests with the ignition on, with the blowers set to max on the controls inside. I checked for fuses which are linked to this but could not find any. I think there has got to be some somewhere but could not see any in the fuse box on the passenger side.

I’m no electrician, but just know how to-do basic tests with a multi-meter. Im wondering whether the connectors actually need to be plugged in for performing the test?

Can anybody help or comment?

Many Thanks,
Adam

 

[a.jenkin]

Have managed to take a another look into this again this afternoon.

This time, all tests done with earth to the battery and blowers full / temp max and air-con on.

I have tried shunting together pins 1 and 5 on the resistor pack connector which is meant to run the blower on full with no result.

I have tested all avail pins/connectors in the following pic and and cannot find any voltage sources, other then pins 5-6 which feed the connector with the black and yellow wires coming out the top, attached to the blower housing (reading 6v).

(not in the picture is the 5 pin connector for the resistor pack)

There are many chunky red wires on this part of the loom which I assume should contain some 12v feeds.

Are there any fuses involved in the heater / blower setup. I have checked all fuses in passenger fuse box and beneath bonnet on right hand side and everything is fine.

Would really appreciate anybody's input on this.

Many thanks,
Adam

 

[realnumber 1]

A week before my battery died the other day the fan packed in. New battery and it worked again. It might be worth disconecting the battery and/or trying a different one.

 

[a.jenkin]

Thanks realnumber, I will give this ago next time i'm playing around with it. from reading other posts on here and renaultforums, there are fuses which control the fans, can someone point me in the right direction for finding these.

 

[realnumber 1]

I just checked all mine under the bonnet and behind the door and ALL were fine.

 

[a.jenkin]

I now have working heaters! Thought I would just finish this post off with my findings.. for all whom are interested. I managed to start making sense of the fixya.com instructions when I removed the blower relay and started testing connections. It turned out the 12V into the relay on one connection was not present. I tracked this back to a blown fuse in the engine bay fuse box. It was the 30Amp green fuse (the fuse next to the 60AMP missing from the pic below - just by the yellow, blower relay)

Once this was replaced, the relay connections were working as expected and I had working fans but on constant max speed .

Next I removed the resistor pack and started stripping it down as I know some people have managed to fix them themselves. It soon became clear that this would not be an option!. I can use a soldering iron but this would need some precision soldering and I wouldn't know were to start!

So, I ordered a new one from renault which in total cost 99.14 inc vat 2 days later fitted and working perfectly!

Hope this info and pics are usefull to anyone else having the same issues!

Cheers,

Adam

 

[polarbert]

I think I've got the same problem.

Did you climate control light up and everything? Look as though it was working but was not blowing any air out of the fans?

 

[keg]

I think I've got the same problem.

Did you climate control light up and everything? Look as though it was working but was not blowing any air out of the fans?

Mines doing this now better check it out tonight see if its a fuse

 

[DMS]

I think I've got the same problem.

Did you climate control light up and everything? Look as though it was working but was not blowing any air out of the fans?

Mine's done this a couple of times mate. Both times it was the resistor pack.
The first time it was replaced by Renault under warranty.
The second time the dealer warranty had run out so I fixed it myself. The resistor is the same one used in various Renault cars - £30 from a scrappie.
Pretty easy to change too.

 

[Lee.]

Was driving back from a mates place tonight and noticed the windscreen wasn't de-misting, then realised no air was coming out of any of the fans.

The controls still light up on the dash though.

Also noticed that the rear wiper wasn't working and then started coming on really quickly even though it was turned off- weird.

Everything was working fine a couple of hours ago, any ideas?

 

[Stunty]

You need part number 7701051272, almost certainly.

 

[Lee.]

You need part number 7701051272, almost certainly.

The heater pack?

People seem to have been describing that fault as the fan being stuck on the one speed rather than not blowing at all?

 

[Stunty]

The heater pack?

People seem to have been describing that fault as the fan being stuck on the one speed rather than not blowing at all?

Yep. Same symptoms as I had. Lights all working on the heater panel. Functioned, as in, upped the blower speed button and the level on the display went up. But no blow.

 

[DMS]

It's definitely shagged. I'm on my third one!

 

[Lee.]

Yep. Same symptoms as I had. Lights all working on the heater panel. Functioned, as in, upped the blower speed button and the level on the display went up. But no blow.

Cheers, sounds like I've got exactly the same problem then. Any ideas on the weird rear wiper though?

It's definitely shagged. I'm on my third one!

Nightmare! Is the part still around £100?

Seems like quite a common problem, is there a particular reason for them failing so often?

 

[DMS]

I don't know how much they cost new. My first was replaced by the stealer under warranty a few weeks after I bought the car. That one failed a month or two later and they wouldn't replace it because I didn't purchase the extended warranty from them. So for my third I went to a scrappie and paid 30 quid for the whole unit and all the connectors. I fitted it myself and it's been fine for almost 2 years now.

 

[Stunty]

103 quid plus vat i think.

 

[Lee.]

Just got round to trying to sort this today with a mate:

Checked blower relay

Checked fuses and wiring from relay to blower motor and controller chip

Blower motor resistances checked: appears OK

Assume problem is controller chip: how is this removed?

It seems to be fused to the wiring leading to the blower motor. (see picture). Is the controller supposed to be replaced along with all the wiring, or can you somehow separate it?

 

[Lee.]

anyone?

 

[.Kev.]

If you look at the picture of the resistor pack the bit which goes wrong is the Transistor which sits on top of the heat sink. There are three legs which go through the PCB and are soldered on the other side (as shown). If you check the resistance between the legs you will find that a f**ked Transistor will be shorted. Its a Mosfet Transistor (STP80f55-08 a rough guess)

I managed to find one on the internet. Cost me 13 pounds inc deliv from the U.S. and i put to use my PCB course and fixed it myself. Easy.

 

[a.jenkin]

@lmonty87, its a bit difficult to see from the picture which part your having trouble with, I think all you need to-do is disconnect the resistor pack from the loom which i remember being a little difficult.

on each side of the resistor pack there are 2 clips holding the connector in, you can use a smal flat head screw driver to release them. I actually broke one of mine when I was doing it.

if you post some better pics, it might be easier to explain.

 

[Lee.]

@lmonty87, its a bit difficult to see from the picture which part your having trouble with, I think all you need to-do is disconnect the resistor pack from the loom which i remember being a little difficult.

on each side of the resistor pack there are 2 clips holding the connector in, you can use a smal flat head screw driver to release them. I actually broke one of mine when I was doing it.

if you post some better pics, it might be easier to explain.

Cheers,

Got confused with the pics at the start of this thread but I think we've got it now. My mates going to try replacing the transistor on the resistor pack at the weekend. Will post up how we get on.

 

[Lee.]

Sorted, now have fully working fans for £1.94!

http://www.maplin.co.uk/module.aspx?moduleno=22997

 

[ferrett]

i have the exact same problem with mine a.jenkins found this info priceless got another from a breakers for 15 quid happy days.... should be made a sticky

 

[Andy_con]

could someone give me some info on where this resistor pack is located on the car?

 

[realnumber 1]

could someone give me some info on where this resistor pack is located on the car?

Just behind the plastic scuttle on the bottom of the drivers side windscreen. Very easy to get to but be careful not to drop the screw when putting the new one back on like I did!

 

[richy22]

I could of resoldered that for you.

 

[Andy_con]

so how do i go about fixing the resistor pack?

very handy with a soldering iron me

 

[richy22]

Strip it down and see whats on there?? I see quite a few mosfet transistors on there...wouldnt surprise me if one of them has popped

 

[Andy_con]

ok will get some pics up

 

[Andy_con]

back is empty

 

[Andy_con]

bump anyone know how i go about the above?

 

[richy22]

Wtf is that crap over it??? Some kind of epoxy???

I can't see fully from the pics but I'd look to trace where the power comes in, there should be a voltage regulator or something on there. Check that for shorts (bleep test with a decent multimeter)

then see if you can see what the part number of that IC is (the one roughly central and has 14 pins)

 

[Andy_con]

very hard to trace anything with all the gel on it.

think ill take the advice from the last thread o0n this page and replace the Transistor

http://www.cliosport.net/forum/showthread.php?t=463727&highlight=resistor

 

[Andy_con]

got it out

number reads

n506ab
75344g

 

[richy22]

Andy re your post on here..

http://www.photonlexicon.com/forums/showthread.php?t=11607&p=152678

Dont worry the pinouts are exactly the same.

 

[Andy_con]

Andy re your post on here..

http://www.photonlexicon.com/forums/showthread.php?t=11607&p=152678

Dont worry the pinouts are exactly the same.

??? why on pl?

 

[.Kev.]

The resin is just there to prevent moisture from getting on the PCB and creating shorts between components. The resistor you want is the one with 3 legs cliped to the heat sink. Mine was label'ed (Mosfet Transistor) STP80f55-08, although i couldnt find a like for like replacement i found a slightly better one.

If you have a decent soldering iron and a steady hand its and easy job.

 

[Andy_con]

The resin is just there to prevent moisture from getting on the PCB and creating shorts between components. The resistor you want is the one with 3 legs cliped to the heat sink. Mine was label'ed (Mosfet Transistor) STP80f55-08, although i couldnt find a like for like replacement i found a slightly better one.

If you have a decent soldering iron and a steady hand its and easy job.

already replaced, but its not fixed the problem.

ive gone from no fans to fan working very slightly the speed control does not speed it up.

so i suspect i need a complete new resistor pack

 

[.Kev.]

By the looks of the Transistor legs in your picture you may have damaged some of the tracks which go to other components.

Mine was the same whan i pulled it off the PCB, i had disturbed a few other components. I had to repair some of the tracks and reflow some of the solder, once this was done it worked fine.

Unfortunately most PCB's ar constructed by robots and computers, hence the tiny parts. Even with the smallest soldering iron i could find it was difficult not to heat up other parts.