I’m hoping some of the same folks who weighed-in on this topic will jump back in and help me with my Mk10 electric window issue.
The driver’s side Mk10 motor burned up right after I got the car in 2020, and it took me awhile to get around to the repair with the myriad of other problems - never was sure what the cause was. The motor that came out looked bad and the window had obviously had poor work in the past, so I attributed it to that. I got couple of good motors from members of this site (thanks again Tony), and installed one awhile back, the window operating well since then.
I was finishing up the new door panels last week, lowered the windows and left the key on for a bit while I exercised and lubricated the rt front door. You guessed it - the drivers motor burned up again. So, obviously, the protection circuit is not working, and I probably have a switch sticking in the down position.
The question I have is whether the problem is with the 6RA relay or the circuit breaker, or both. This relay is not available new. I’m going to take it off today (hard to get to inside the left upper fenderwell) and try to test it. I believe the C2-C3 should show continuity, then broken continuity with current to W1. Any thoughts about that? This is an unusual circuit, and I don’t fully understand it, even with the prior explanation. It seem like a somewhat delicate balance between two electrical components designed to release the smoke from my wires.
It seems like the circuit breaker should have at least tripped before the motor toasted, so I’ll replace it - looks like an off the shelf unit would work, but I’m not confident it will protect my motors, and I can’t afford to risk the others. I’ve got only one good spare motor left. I’m also thinking of installing a kill switch for the whole system. If a motor smokes while I’m driving, I can’t just shut the car down.
Some thoughts:
Leave off the second relay and just have the new breaker inline?
Replace both breaker and relay, repurposing another 6RA type. If so, which one? I think must be NC. Manual photo above lists cut-in and drop-off voltages, coil resistance - not sure this will work.
Look for a good used 33247B
convert to manual windows (buy another new set of rear door cards)
Remove all fluids and put the car in the bay as an anchor for my sailboat
Well, I’m solving some problems here.
First, the relay tests good. True to past experience, the previous mechanic was a knucklehead. The 30 amp replacement breaker was installed backwards and both relays were miswired. Basically, they bypassed the relay and the breaker on the way to the electric windows. I am going to replace the breaker and try a 30A. There is no fuse in the window circuit on my wiring diagram, so I’m not sure where the 50A comes from. If that’s bonafide, someone please let me know.
Btw, a pita to get these out - I managed to do it by removing the larger input relay and disconnect all wires. The bracket mounts through bolts that are accessible through the fender well, so that’s not too bad. I have a series 2 XJ6 brake master and booster, and the flexible reservoir hoses allowed me to swivel them out of the way. Not sure if this would work on a stock setup. Would hate to have to pull the brake controls for something like this.
Hi Ron. I went through the topic and i guess 50A comes out from my previous post, when window circuit should be under 50A fuse (meaning the main fuses box behind the dash). But its true, that service manual page i posted earlier mention that circuit breaker is rated at 65mA. Unfortunatelly, cant tell you more at this point. My garage is not temperated and living circumstances are “on rollecoaster” for a few months, so work on my car is much slower than expected to be…
Marek, if you look carefully at the wiring diagram and the car, that circuit goes through a post on the bulkhead and does not go through the fuse block. There is no fuse in the circuit, thus the breaker. The feed wire to solenoid #1 is hot. When I rewired with the 30amp breaker, I tried stalling the window for a couple seconds, but the circuit didn’t cut out right away. I was afraid stall it for too long. At least the 30amp doesn’t seem to be too small.
I just wired a kill switch for the whole electric widow system. If it starts to burn up while you are driving, you can’t just shut the car off. I’ll keep it off when I don’t need the windows. It’s the black one next to the ASC over-ride switch.
an old taxi driver once told me manual winder windows were preferable to electric ones because if someone needed to vomit out the window, it was quicker for them to operate the winder
Hey, Tony, when you get around to looking for that other stuff, would you see if you have a grill for the stock speaker housing in the rear parcel shelf? whoops, meant that to be a pm.
