D1 Rear Window Switch Blowing Fuse

[amg61]

1996 D1 118,000 miles

I have read about the rear window fix for the D1 and have both soldered AND replaced the rear window ECU with some success in the past. However, recently, I replaced the rear window ECU and the rear windows worked at first, but then I continued to blow the 30amp fuse. So now I'm thinking the ECU is probably OK, but somewhere there is a short or grounding problem. I am not the best at electrical problems, both FINDING them and then FIXING them, so any help would be appreciated.

When I try to roll down the rear windows using either of the switches in the center console, between the two front seats, the windows go down and then after a couple of tries, the fuse blows. Now it is possible the same thing would happen if the switches on the back doors were pushed too, but I'm never back there to test them when the fuse is fine (maybe i should). I have replaced the rear window regulators in the past and maybe I shorted something during those repairs, or who knows. Not sure really how to find this problem.

I assume that window ecu repair kit that atlantic british sells, http://www.roverparts.com/Parts/AMR1282RK.cfm only works if the ecu is having problems and won't help avoid a continually blowing fuse, unless the short is located on the wire in the connector that this bypass works around (unlikely).

Any ideas would be very helpful

Thanks!!!!

 

[amg61]

anyone have any ideas??? thanks.

 

[amg61]

aw c'mon guys, someone must have some ideas for me. of course, i guess i could just keep it this way and use it as an explanation to the kids as to why they are not allowed to open their windows, EVER!

 

[buck66]

had similar issue on my 96DI. turned out to be rear window switch would jam on. motor would try to continue operating with window at full stop. eventually fuse would blow. pulled switch apart cleaned and greased....no issues since. 15 minute fix.

good luck,

jeff.

 

[amg61]

had similar issue on my 96DI. turned out to be rear window switch would jam on. motor would try to continue operating with window at full stop. eventually fuse would blow. pulled switch apart cleaned and greased....no issues since. 15 minute fix.

good luck,

jeff.

Which switch were you having trouble with, one of the ones in the center console, or one of the switches on the rear door itself? also, wouldn't you hear the motor running on even after the window had stopped, alerting you to the problem? I never heard any continuous motor effort, the fuse just blew out of nowhere.

how best to find this problem?

thanks.

 

[buck66]

in my case centre console switch. I never noticed any motor noise but I wasn't listening for it either.

good luck,

jeff.

 

[amg61]

in my case centre console switch. I never noticed any motor noise but I wasn't listening for it either.

good luck,

jeff.

Really need some ideas here, please. I cleaned the center switches as you mentioned (they looked fine by the way) and the rear windows worked for a few days longer than normal, but the fuse is blown again now. Not sure why this is happening. What would it mean if, when the window was fully closed, I pushed the switch in the "closed" direction, having not realized that the window was closed, and then the fuse blew? Not sure if this is what happened last time the fuse blew and I may really be stretching for answers, but thought I would ask anyway. In any event, I have no idea why the fuse is blowing, but really would love some help. Thanks!!!

 

[amg61]

Still searching for some good ideas here. Thanks.

 

[amg61]

Anyone???? Fuse is still blowing.

 

[greenD1]

Sorry I don't have any help with the short unless it is in the ecu. If the ecu is the problem this is an easy fix. $2.50 at the local hardware store. http://www.roverparts.com/Parts/AMR1282RK.cfm

 

[KevLar]

It shouldn't make any difference to the fuse if you hit the up button when the window is already up, or down when it's already down. The motor is not going to draw any more current than it normally does just because the window is at full top or bottom.
Based on the info you have provided, it definitely sounds like you are drawing too much amperage through the window circuit, and the most common cause for this would be a short as you mentioned. The short could be in the wires that feed power to the regulator motor, or it might be in a shorted motor. Since you say that the motors work (?) with a new fuse, then it seems more likely that you are dealing with a shorted wire problem. The question is where is the short ?!

You will need to do some circuit tracing to locate it, but there are some common sense things to consider before you start ripping the truck apart. You want to think about those areas where the wires would be subject to wear, which over time would chafe the insulation and eventually allow a bare wires to touch another wire or another ground point. Areas that could be a problem would be where the wires flex (inside the sheath between the pillar and the door), or where there's vibration or movement (the window moving up & down inside the door and possibly rubbing against the wire harness that goes to the motor). These are the places I would be concerned about. Since you are not dealing with a window that simply won't work, I would not be suspicious of a corroded wire or ground point, because that would simply mean the power window would not operate because the circuit was no longer closed (grounded).

You say that you are blowing fuses when you use the buttons for the rear window on the center console. You should make sure that the buttons on both rear doors actually are making the window move UP and DOWN without blowing a fuse. If that's the case, then you can eliminate this part of the circuit as a potential short location. However, if you find that the fuse is blowing when using the front OR rear buttons, then the short must be located inside the motor (again, not likely since they are working), or the short is located at a point BEFORE where the front console and rear door window buttons separate from the circuit. In other words, both front and rear buttons causing a blown fuse indicates that the short is common to the harnesses that feed both the front console and rear door switches.

Next, you need to check if the left or right rear window, or both windows is causing the fuse to blow. This will tell you that the short is located between the window button that is being pressed when the fuse blows and the regulator motor for the window which is blowing the fuse. If both windows are causing the fuse to blow, then you can deduce that the short is either in the switches (both of them... which is unlikely), or it is somewhere in the harness between the switches and the regulator motors of both windows. Since the rear window wire harnesses split up not far from the center console, the short will have to be located pretty close to the console itself, before the left and right harnesses split apart. Since there are no moving parts in the center console that I can think of which might damage the wires, I think it's unlikely that you will find that BOTH rear windows are making your fuse blow.

Once you have narrowed down the culprit window, you can use a multimeter or Ohmmeter to confirm that there is a short between the wire(s) at the switch and ground. Disconnect the wires from the switch and put one probe of the multimeter on the end connector of one of the wires and the other on the other wire that forms the circuit going to the regulator of the suspect window. If you get an indication of resistance (probably full deflection, infinity or overload), then there is NO short between the two wires. If you get 0 Ohm (Zero) resistance, then you have an open circuit, therefore a short between the wires. If not, next put one probe on the end connector of one of the two wires and the other probe grounded to the chassis, preferably the door itself. If you get some resistance (again, full deflection or infinity), then there is no short in that wire. If you get 0 Ohms, then that wire is the one with the short. At this point the last wire to be tested should be the cause of the short, so put your probe on the end connector of the last wire with the other probe still grounded and confirm the sort (0 Ohms). One you know which wire(s) is causing the short you can start tearing stuff apart to visually examine the wires and locate the damage. When you find the spot it is considered "best procedure" to replace the entire run of wire because there could be some heat generated damage that is just an accident waiting to happen. That call is up to you. If it appears that the damage is very localized and you don't see signs that the insulation has melted anywhere else, (including ADJACENT wires which might also have been affected if the short was located in a tight bundle of wires), then you can consider a localized repair using heat shrink insulator rather than electrical tape if possible. Remember if the repair is inside the door, there is water, salt and crap that get in there which will easily get past electrical tape ! You'll need to cut the wire at the damaged spot anyway to clean and remove the damage, so this is when you slip on a length of heat shrink before you SOLDER the wire back together. Do not simply "twist' the wires and expect that to last ! If you have to remove a fair bit of wire there might not be enough slack wire in the harness to rejoin and you might need to add a length of new wire, so make sure it is of equivalent gauge or you'll be creating a "hot spot" that will come back to haunt you later, and you will be doing the exact sam repair all over again.

So before you get settled in for some circuit tracing, you should buy yourself a few packages of fuses because you go though several Also, you should note that when doing this kind of hit and miss circuit tracing for a short, you are in effect allowing over-current through the circuit for a very brief period (the time it takes for the fuse to blow, which is NOT instantaneous). There is the possibility of overheating the wires in the circuit with repeated attempts, particularly if the over-current happens at short intervals and the wires/insulation don't have a chance to cool. So allow a few minutes between attempts for that to happen, which will probably be the case since it will take some time to replace the fuse... If this was an aircraft, we would use more specialized and sophisticated equipment (time domain reflectometer and test set circuit breakers) to prevent this kind of potential damage. You might want to buy fuses that are the next gauge down from what is supposed to be used for the circuit, so that you don't damage any of the wires through overheating by repeatedly allowing high current though the circuit, but this is probably overkill for your application, and you would need to know the actual current draw of the circuit to pick a suitable downgraded fuse anyway...

So, in summary:

1. Buy some spare fuses
2. Check operation of left rear window using front console button --> Problem YES skip to 7/Problem NO continue
3. Check operation of left rear window using rear door button --> Problem YES skip to 7/Problem NO continue
4. Check operation of right rear window using front console button --> Problem YES skip to 7/Problem NO continue
5. Check operation of right rear window using rear door button --> Problem YES skip to 7/Problem NO continue
6. With a culprit window and button identified, determine if fuse blows when window raises or lowers
7. Examine the suspect wire(s) from known good location to regulator motor looking for short.

Hope this helps !

Let us know how you are doing, and if you are having fun

Kev

 

[amg61]

KevLar - as usual, thanks for your detailed summary. I was wondering if it was possible that the connector to the ECU was damaged, as I have changed the ECU a couple of times and tried the solder technique and that is where the short may lie. In taking that connector on and off, I may have weakened the wires going to it. The poster before you mentioned a jumper wire technique, sold by one of the vendors, that essentially bypasses the ECU just for the rear windows. Here is a link: http://www.roverparts.com/Parts/AMR1282RK.cfm

If you click on the link for the Instructions at that website, you will see what it bypasses. Maybe this is what I need to do, and even if it doesn't work, then I won't ever have to worry about the rear window ECU solder joint problem again.

What do you think???

 

[KevLar]

Well, it's worth a try and is not much more involve than the circuit tracing that I explained. In fact, you are only popping out the glove box and footwell panel, which is much easier and quicker to do than popping a door panel.. Since I am a more a DIY kind of guy, I would definitely scoff at the idea of paying someone $15 for a piece of wire and some connectors (not to mention shipping costs and waiting time) !!!!

Unless you like to give people money for nothing, this is what I would suggest:

The procedure posted on the website is all you really need ! It gives you the wires to look for and where they are located.

Go to an automotive supply place and get yourself some wire of the same gauge if you don't already have some handy. You can also get some quick connect press fit electrical splices, but you can do without them. I would suggest a more reliable and more permanent solder joint, assuming you have a soldering gun/iron and some solder. Also, get yourself a pack or length of heat shrink electrical insulation large enough to handle the wires you are dealing with, if you don't have some handy.

Pop the glovebox and footwell panel and follow the instructions, except instead of using the $15 piece of wire, use your own wire and splice into the harness as described. Cut and strip 1/2" of the White/Pink wire (position "H" in the ECU connector) as per the instructions, then slip on a length of heat shrink insulation and slide it away from the heat of the soldering and solder an appropriate length of your new wire to the stub from the connector. When the soldered joint has cooled, slide the heat shrink insulation over the repair area and heat the insulation sleeve to seal off the repair. Do the same for the wire in the footwell. The joint you will be making here will be slightly different from the first one because you are tapping into an existing wire, in other words, you will be ADDING a wire to the existing Green/White wire at close the connector there. Just cut the Green/White wire and strip both ends, maybe 3/4" instead of 3/8" this time. Take the other end of the new wire from the glovebox, also stripped 1/2" and twist it to one end of the Green/White Wire. Now slide an appropriate length of heat shrink insulation over this pair of wires and slide it out of the way from the solder joint. Next, take the second end of the Green/White wire and twist it to the pair you just twisted (Green/White + New) and solder the joint. Lastly, slide the heat shrink over the repair once it has cooled and heat up the sleeve to seal the repair.

A few things to keep in mind: First, make sure that you cut any wires at least a few inches from the connector to give yourself some room to work, such as twisting the wires together so they hold to each other when you are soldering. Also, when soldering, make sure that you are getting good penetration of the solder into the wires. I don't know if you've done a lot of soldering before, but if you haven't, basically just get the iron on the bare wires and touch the solder to the tip occasionally until it starts to melt, then run the solder into the tip and as it melts, it will "wick" into the twisted wires and suck up the solder which will result in a really good joint. If you don't leave the iron on long, the solder will not penetrate fully, and the joint might crack apart and you'll get intermittent or no rear windows again ! Same goes for the triple wire "tap" joint... Here you are dealing with 3 wires and what that does is act like a heat sink (drawing heat away from the iron like a radiator) so the thicker the wires are, or the more there are in a joint, the more heat it takes to get the solder to thoroughly wick into the wires for a good joint. Also, just to be clear on how the triple wire tap joint should look, I am using the keyboard to do a rudimentary illustration. When you have finished the soldering, the pair of wires on the left (Green/White + New Wire) will be side by side, and the heat shrink sleeve will cover the pair of wires on the left as well as the single Green/White on the right. So one piece of heat shrink for the whole "in-line" repair, not some weird looking "T" splice which will be impossible to insulate with heat shrink:


Green/White ___________
\ ___________ Green/White
New Wire ___________/

So give that a try. If you already have the supplies I mentioned, it should take 30 min. max. If your problem is not solved, then you are back to circuit tracing

Kev

 

[KevLar]

Shite... The little illustration did not come out as planned The middle line should be shifted over to the right so that the two slashes line up. Basically the layout of the joint should be like 2 lanes of a highway merging into a single lane, NOT a "T" intersection.... Hope that explains it better.
Kev

 

[amg61]

Kev,

Your detailed advice is always welcome, but I just used the pre-prepared $12 kit and I am done with it. So far, so good. Fuse has held, so let's hope this was the trick. Thanks again.

 

[KevLar]

Kev,

Your detailed advice is always welcome, but I just used the pre-prepared $12 kit and I am done with it. So far, so good. Fuse has held, so let's hope this was the trick. Thanks again.

Cool, that's great news Not only are the windows working, but now you know where the problem was too ! I guess you'll let us know if it starts acting up again, but hopefully this fix will be the end of it. Pretty sad that the OE part fails so often that there's actually an after market kit to deal with the problem though. Pfft ! Let's keep our fingers crossed that Land Rover never decides to produce an electric vehicle
Kev