electric window problems

[rachaelk]

me again my pass side window has decided to call it a day, ive had a good look and its not the switch as ive swapped them over and it works, do you think it could be the regulator, i wouldnt mind but ive just had that done in my landrover lol

thanks guys

[Matt Parker]

The most likely fault will be the window regulator motor, but before you go about replaceing it check your fuse as it may just be a blown fuse, if thats ok then you can strip the door down and check/replace the motor. With the door panel off disconnect the wiring harness plug for the motor and test for power with a multi-meter for the power supply, and then to test the motor using a spare battery or 2 long bits of wire from the battery power up the motor dirrect to test it.

[rachaelk]

thanks for the reply, the reason i havent touched the fuse is that surely it cant be that if its just 1 window thats stopped operating i thought the windows were on the same fuse, i am going to double check then get yet another window reg

[Rob Bell]

Certainly worth checking the fuse; it's the easiest and cheapest part to replace! But I suspect you're right - blown fuse will usually result in loss of both windows, and also the heated door mirror elements.

If the window is not revived by swapping over the switches, then it does point to a problem with the motor, the mechanism or the wiring loom.


If there is no noise, no movement of the motor and assuming that the motor is not getting warm, then this suggests that the lift mechanism is not jamming, and the problem is likely to be electrical rather than mechanical. Indeed, if there is no power reaching the motor, then it is the loom that is failing - perhaps as it passes into the door (fractured and/or shorting wire?) A multimeter/circuit tester will be helpful here. Or you can do as Matt suggests - wire up the motor directly to the battery and see whether the motor then works... or not.

[Matt Parker]

there is a fuse for each window, I had a TF in with the passenger window stuck down, at first I thought it would be either a faulty window mech or the SCU but after checking the switch and then stripping the door panel off and having no power anywhere I thought I'd just check the fuse and there it was, simple 15amp fuse had blown lol

[Rob Bell]

Absolutely right Matt - fuses 4 and 5 for RH and LH window lifts Surprisingly, I don't think this is a problem that occurs all that frequently, but an overloaded motor due to a sticking window lift could certainly draw sufficient power to blow a 15A fuse

[jld]

Got a similar problem on my TF. Drivers side window will go down in 'one shot' mode, and will not go up. Motor is OK (works well with external 12v supply) and switch ok (swapped with passenger side).

Any ideas?

[Stan_B]

I would suspect the BCU, depending on model year this is either the little box under the carpet just ahead of the drivers door, or part of the well known Pektron BCU behind the centre console.

[jld]

thanks for that Stan. Guess its behind the centre console (its an 04 reg) as there's nothing behind the carpet.

Now just to work out how to get to it and what to do about it (will it need replacing and does this cause other problems)

[Stan_B]

If you can live without the one shot do what I did, bypass the BCU run 2 wires from the door to the switch, you need a 12v as well. It appears that the Pektron relies on earthing one or t'other wire from the switch to command the motor.

[talkingcars]

needs a new window motor.

my opinion, cheap on ebay.

might as well buy a whole car just in case the other one goes as well!

[willyphixitt]

Hi jld,

I've just posted my findings (here) yesterday. One half of a dual relay module had failed. I swapped this with the washerer pump relay and got everything working. Hope my experience helps.

willyphixitt

[jld]

I'll try that,not had much time past few days but long weekend coming up. Thanx

[Stan_B]

This made me put mine right, I was surprised how easy it was to fix the SCU. You only need to take one closing panel off. The passenger footwell is easiest. The 2 halves of the case just ping apart , i used 2 flat bladed screwdrivers. You need a solder sucker and reasonable iron. I was able to borrow both and took the PCB in the Fiat to do the work. I did get some help from a pro to get the old relay out. I got the new relay indirectly from Technozen on .org You can see its a different source to the suspect OE fit. Refitting was easy, I plugged up the 2 sockets on the OS then fiddled the 2 on the NS in once the SCU was in place. I reused the original bolt, it has an unthreaded starter section to make re-fitting easier. i just cut a screwdriver slot across it while it was out. I now have one touch down again
Interestingly the drivers window wasnt the only dud relay, one coil was open on the washer pump relay so i wonder if someone else has swapped them around before? The last but one pic is "borrowed" from .org and it shows which is which. It was vital for me, otherwise with 2 open coils i wouldnt have known which to swap.
Finally , maybe we should have a "how to" sub forum, an idea shamelessly lifted form another site.

[willyphixitt]

Glad to see you've got your SCU fixed, Stan.

A good soldering iron and good solder sucker is the key to success here.

willyphixitt

[Fiddler]

Fuse 6 seems to be the secret one... mine gone replace ok for Windows
Unplug engine bay fan and kick start with 30a Fuse just a blip to get going
Spray penetrating oil might help.then fit proper rated Fuse 15a

[cymrumark73]

Both my windows dont work. I’ve checked the pull out fuses and all are ok. What are the other fuses and could it be one of the yellow relay fuses

[MGDave]

My TF stopped working on the drivers side. Had my BCU repaired and that solved the problem only for the problem to come back a month later. Auto electrician eventually found the fault in the press together connector in the door. He by passed this and problem appears to have been resolved.

Could be either or for your problem but the connector by-pass is by far the cheapest....

[davidb]

For what it’s worth, my windows stopped working when the engine bay fan seized as they’re on the same fuse (6 if memory serves). Agree with the post above that unplugging the engine bay fan (not radiator fan) and replacing fuse 6 is a good test. Went through many 10A fuses before I realised!!

Haven’t yet decided whether using the windows as an indicator that the engine bay fan is toast is lunacy or genius!

[Notanumber]

I had exactly the same problem as David. The passenger side window suddenly stopped working during the MOT. It took a while to track down. Fuse 6 solved it. The root cause was a defective engine bay fan motor as this is on the same fuse.
The engine bay fan is rarely actuated in normal use so this isn't something that will happen every week. In my instance the duff fan wasnt blowing the fuse immediately, only after the fan had been actuated for around a minute that it blew the fuse.
Taking the old fan motor out of service and replacing fuse 6 kept the passenger window working fine and as soon as it arrived a good 2nd hand replacement engine bay fan from 'Bitz' finished the job.