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Renault Laguna I - Phase 2 - Heating and Cooling - Heater Fan 1,2,& 3 speed not working + FIX

182K views 112 replies 62 participants last post by  Jlbsmart 
#1 ·
Renault Laguna I - Phase 2 - Heating and Cooling - Heater Fan 1,2,& 3 speed not working + FIX

Hi Just thought I would share with you how I have fixed a Laguna heater blower that worked in speed 4 but not in 1, 2 or 3. The root of the problem is there is a device called a Thermal Fuse in the circuit for the 3 lower speeds but not for the top speed. Once they blow they have to be replaced. These special fuses can be obtained from somewhere like RS Components. Have a look at:

http://www.maplin.co.uk/search.aspx...u=y&criteria=Thermal Fuses&doy=15m1&worldid=3

This is what the fuses look like. You would have to check that is has the current carrying capacity of the one fitted to the resistor pack which is 16 Amps at 240 Volts or 25A at 120V. I bought mine from RS some years ago, picking up a couple at the time, I knew it would come in handy eventually!
Also look at :
http://www.atconline.com/microtemp-detail.htm

It is located in the resistor pack that is inserted into the airflow, the Haynes manual calls this the "Heater Blower Motor Resistor/Control Unit". Note the Haynes manual says this unit on a car with Air con cannot be renewed seperately - correct, but it can be repaired! I have done the same job on both types now!
1. Extract the unit, on the aircon you have to leave the unit dangling on it's wiring harness.
2. remove the aliminium shield by bending the lugs straight and gently prising it off.
3. identify the fuse and snip it off leaving the legs attached to the terminal posts(Important this otherwise you will not have anything to connect the fuse to!). You can gently bend the curly resistors out of the way , putting them back once finished.
4. :steam: Now comes the fiddly bit! As the fuse cannot be soldered in (it would 'blow' because of the heat) you have to fit the fuse by mechanical means. I used some small plastic terminal block ( 5 amp size , I think), sometimes called chocolate block, with the plastic cut off. This leaves you with a small brass tube with 2 terminal screws in it. Arrange the tubes and the fuse so that the fuse is in circuit but not touching any other part of the circuit eg the curly resistors, It doesn't matter which way round it goes!
5. put the shield back on, bending the tags over again and double check to see there are no undesireable shorts anywhere
6. Put the unit back in connect up and away you go.

I am an electrical engineer so found this a fairly easy task but any competent DIYer should be able to save them selves £50, the fuse costs about 50p
HTH

Sorry meant to add: my fuse was marked
MICROTEMP This is the manufacturer
TFDAGG
G5A01 This is the part number
TF110C This is it's 'blow' temp ie 110 degrees C
 
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#3 ·
Hi Baz, It is behind the glovebox. It is called the "Heater Blower Motor Resistor" in the Haynes manual, page 3.11. For cars with aircon it is located differently, still behind the glove box but part of the blower casing. Whichever model, Just follow the cables from the blower motor to find the resistor unit. Hth, Barry
 
G
#5 ·
Ben I am very pleased to see this superb little slice of info from a member on his 5th post !!

Lots of people tend to leech from the forums without adding content so your actions have to be applauded.

Welcome on board matey.

I have moved your post to the Laguna Knowledge Base section for future reference.

L20 ( Site Mod )
 
#6 ·
Laguna thermal fuse - follow up.....

Fascinating,

My son had this problem on his 'phase 1' about 4 months ago and 'my' solution to it was for all practical purposes identical - (got an RS account which helps when getting awkward bits like thermal fuses!).

My point is however, that thermal fuses are there for a reason, i.e protection when things get too hot - which in this system probably means poor or diminished airflow, ( given the resistor pack is 'naked' and housed directly in the main blower pipe to keep it cool).

While you've got the glove-box out it only takes an extra 10 minutes to uncouple the blower motor ( up against near-side panel) and check inside the housing and entry / exit pipe(s) for debris.....of which there was quite a bit on my son's Laguna.......mainly dry leaves.

This seems to be so common that maybe this fault is worthy of a few jpgs to point people in the right direction.

Perhaps we could set up a source for 110'c thermal fuses !!

:d

Spiro'
 
#7 ·
Good Point there Spiro'.

Fuses are exactly for that purpose, always check to see why it blew before replacing it, no matter what type of fuse. I didn't mention checking to see if there was any debris in the trunking, I should have really. In the two cases I had there was no problem like that but as you found out, it is highly possible. Some of the web sites I visited whilst researching the problem mentioned that they do sometimes blow for no apparent reason, but it is alwaye worth checking!
Regards,
Barry
 
#113 ·
Good Point there Spiro'.

Fuses are exactly for that purpose, always check to see why it blew before replacing it, no matter what type of fuse. I didn't mention checking to see if there was any debris in the trunking, I should have really. In the two cases I had there was no problem like that but as you found out, it is highly possible. Some of the web sites I visited whilst researching the problem mentioned that they do sometimes blow for no apparent reason, but it is alwaye worth checking!
Regards,
Barry
I'm i right in saying different models have different wattage mine was 94watts and I think you go down to about 62 Watts so make sure you get the correct on a site on ebay ask for your reg and it tells you if it will fit your model or not which i found very helpful
 
#8 ·
Hi again 'Ben 1400'..........

In my experience as well.........thermal fuses ( in whatever application), do seem to suffer from age.

It just occurred to me that if anyone else is trying this 'fix', it takes but a few extra minutes to check for debris in the airflow.

Interestingly, I had a very similar experience on a C-Class Merc about 18 months ago........again, blower motor overheating because of leaf debris.

Trouble is - I think we all tend to ignore this part of the car's functionality.....right up to the point where it fouls up, usually on a freezing cold night / morning!

Mind you, now I've sorted out his blower motor, it seems the best the heater can manage is 'mildly less cold than without it". Bet its a blocked heater core.

I'll see if I can put together a step by step with a few pics given the number of people raising this topic.

Thank God its not got climate control!

Regards m8,

Spiro'
 
#10 ·
Hi Vornstar,

Ratings on these devices can get confusing. The 'blow' temperature is of course fixed (110'C in this case), but the fuse element is usually quoted at 240v (e.g. 10A). At lower voltages the current rating is higher....ca 25A at 12v.

The RadioSpares part number for a 10A 113'C fuse is 176-9255 - (if you have an account with them). About 60p each but come in packs of 5. This type appears to work / suit OK.

I don't have a 113'C fuse at present but I do have both 99'C and 121'C types which are quite close.

If you would like one you could send me a SAE with a few spare stamps to cover the cost of the fuse.

Remember you CAN'T solder these.

(PM if you are interested)

IF there are others out there who would like these fuses or a few spares in the cupboard just in case then post here or PM and I'll put an order into RS specifically for this.

Regards,

Spiro'
 
#12 ·
LAGUNA1 PHASE 2 HEATER BLOWER MOTOR RESISTOR

Hi Baz, It is behind the glovebox. It is called the "Heater Blower Motor Resistor" in the Haynes manual, page 3.11. For cars with aircon it is located differently, still behind the glove box but part of the blower casing. Whichever model, Just follow the cables from the blower motor to find the resistor unit. Hth, Barry
Hi, I have found the postings regarding fixing the blown thermal fuse in the resistor pack very interesting. However, I am unsure of where to find the blower motor itself on my 2000 W Laguna 1.8 Sport with air-con and passenger air bag.
I have removed the glove box itself but cannot see anything that resembles any of the diagrams in my haynes manual. All that I can see through the glovebox aperture is a large black plastic panel behind the glovebox which looks like it is part of the heater ducting. Am I looking in the right place? Any advice would be appreciated.
 
#13 ·
Hi David,
The heater blower is in the passenger side footwell. Put your head in the footwell & look up, it is covered by a piece of shaped felt material which you will have to remove from the clips that retain it, once this felt is out of the way you should easily see how the blower is held in.
Regards,
Barry Chapman
 
#15 ·
Laguna blower motor repair pictures

Hi Ben,
Thanks a million! your repair details were absolutely spot on. It is not that difficult either. I did the repair today to my Laguna took about an hour and a half without the help of Mr Haynes. I took a few pictures during the repair, thought they may be of use to others?
First picture is of the resistor pack sat on top of the blower motor. Disconnect the 2 plugs and tuck out of the way. The second is of the resistor pack itself after it is unclipped (a little fiddly) but it can be done with the blower in-situ, the fuse is under the 3 'curly' resistors. The third is with the shield removed so you can get access to replace the thermal fuse. I tried R.S components for a replacement, but they don't stock this line any more???? So go to Maplins and ask for a RA64 THERMAL FUSE 110C, these are 69p each. The connects (5A) Ben refers to are part number L97AR at £2.79 for 3 strips.
Hope you don't mind me adding to Ben's notes, I just thought this additional info may be of use to someone without a workshop manual. Once again Ben, Thanks, you saved me a few quid here!!!
 

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#16 ·
Laguna heating not working & losing water

Hi, Sorry if some of you have seen this before but I think it might be better here than where it was. My Mk1 laguna has been working perfectly for the 9 months that I've had it, but this week the heater stopped working and the engine began to run a little hotter than normal. It also started going through a lot of water. The water doesn't seem to be leaking anywhere as ther are no pools of water under the car. Have checked the oil cap for any furring and there doesn't appear to be any. Is this a case of a possible cracked cylinder or a faulty head gasket. It runs ok but needs a lot of water. Should I stop driving it? Apologies if this seems a daft question too.
 
#17 ·
Just to add...

I've just done this on mine as well. If you've soldered before, you can solder the new fuse into position with no problems. I wrapped the leg round the tab and then soldered it into place. Use a heat spreader on the leg of the fuse, or get an extra pair of hands to clamp the leg of the fuse with a pair of pliers. That'll keep the heat away from the fuse while you solder it.
 
#20 ·
Quavey,
Your problem sounds a little more serious, this repair (replacement of the thermal fuse on the resistor pack) will only work if you still have your fan working on full power i.e. bypassing the blown fuse. If your fan does not spin on full power I think you need to look for a different solution...?
 
#24 ·
Hi all,
I am having probs with my heater fan but dont seem to have the same setup. My blower motor wont work at all. I have a 95 laguna est with climate control. The wires come out of the loom to a 1" sq relay box and then into the motor. When you turn the blower on the relay clicks and the fan bars come up on teh screen but then it clicks again and service comes up on the display.
I cant find a red and black wire going to anything that looks like the resistor my Renault parts dealer showed me.
Anyone got any ideas?
Ta
 
#26 ·
Another fix.

Hi,

A friend of mine has a Laguna estate, type and year uncertain but about six years old perhaps.

Last week his heater blower motor became inoperative regardless of the control switch positions.
With the help of this Forum I located the resistor pack behind the glove-box. After some voltage measurements on it, I concluded that it was probably faulty. After removal I checked the Thermal Fuse that is often the cause of failure, but that was OK.

We obtained a pack from a local car breaker, fitted it, and the problem was solved.

I decided to do a "post mortem" on the faulty unit and under my illuminated magnifying glass I noticed a suspect "dry" soldered joint on the circuit board. I resoldered the joint and the pack worked OK!

The joint in question was the one just above the terminal, onto which the red output lead to the motor is connected.
I have attached a picture.

Before condemning a resistor pack, it would be wise to check all of the soldered joints on the circuit board closely and resolder any that look suspect. BTW, there was no sign of overheating at the faulty joint.

Thanks for the help of other posters on this subject.

Regards,

riumreh
 

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#55 ·
Hi,

A friend of mine has a Laguna estate, type and year uncertain but about six years old perhaps.

Last week his heater blower motor became inoperative regardless of the control switch positions.
With the help of this Forum I located the resistor pack behind the glove-box. After some voltage measurements on it, I concluded that it was probably faulty. After removal I checked the Thermal Fuse that is often the cause of failure, but that was OK.

We obtained a pack from a local car breaker, fitted it, and the problem was solved.

I decided to do a "post mortem" on the faulty unit and under my illuminated magnifying glass I noticed a suspect "dry" soldered joint on the circuit board. I resoldered the joint and the pack worked OK!

The joint in question was the one just above the terminal, onto which the red output lead to the motor is connected.
I have attached a picture.

Before condemning a resistor pack, it would be wise to check all of the soldered joints on the circuit board closely and resolder any that look suspect. BTW, there was no sign of overheating at the faulty joint.

Thanks for the help of other posters on this subject.

Regards,

riumreh
hi can you tell me how much it was for a new resistor pack ..as i think i have the same problem i have a laguna 2 ..year 2000 ..it was working and then just nothing and renult want 80 pound just to look at it so i think i will try to have a look at this resistor as i cant seem to find any fuse for the blower ..took it to qwick fit to see if it was air con and in this case they were the only 1ns that would look at it for free ..they couldent fix it and at 1 point couldent get the car to restart and had to phone renult ..but fair play at leat they had a look with no charge .cant beleave im saying this but well done qwick fit ....my blower airon heater nothing comes on was that the same for you no waring just stoped
 
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