Central locking!
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RTTBMW
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Hi,
I noticed today on the fuel cap door, it has a auto lock function. However this car has no central locking. Was this fitted as normal or could this car had central locking in the past? What was the option code for central locking?
regards
RT
I noticed today on the fuel cap door, it has a auto lock function. However this car has no central locking. Was this fitted as normal or could this car had central locking in the past? What was the option code for central locking?
regards
RT
E30 325i Mtech 2 1990 (Registered in 1991)
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RTTBMW
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Now I realise I should have central locking. Anyone recommend the best way to fix this or replace with the best product suitable! Do BMW still do this parts?
regards
Richard
regards
Richard
E30 325i Mtech 2 1990 (Registered in 1991)
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kdevitt
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I'd start with the red / black wire mod - do a search on here and you'll find details on it.
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BenHar
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Brianmoooore
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I think many of the parts (possibly all) are still available from BMW, but the price will be horrendous. Plenty of second hand parts around, which are as good as new.
There's a common problem, caused by negligence or over enthusiastic undersealing, that causes severe damage to all or most of the locking actuators, which may be why your car no longer has it.
You need to do a search over the car and see what parts are still fitted. Locking ECU is inside the RH sill. You need to remove the RH front speaker to access it.
There's a common problem, caused by negligence or over enthusiastic undersealing, that causes severe damage to all or most of the locking actuators, which may be why your car no longer has it.
You need to do a search over the car and see what parts are still fitted. Locking ECU is inside the RH sill. You need to remove the RH front speaker to access it.
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RTTBMW
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Hi,
Yesterday I took front interior out! I was curious about a few wires with nothing on them! They where behind the pasenger side carpet next to the speaker panel! Twin Blue wires and a single Blue red one! Are they something to do with the central locking?

Found another one at the centre console! Wraped in blue tape! Red and black wires!

Any suggestions would be great! Nothing found on drivers side of wires loose!

regards
Richard
Yesterday I took front interior out! I was curious about a few wires with nothing on them! They where behind the pasenger side carpet next to the speaker panel! Twin Blue wires and a single Blue red one! Are they something to do with the central locking?

Found another one at the centre console! Wraped in blue tape! Red and black wires!

Any suggestions would be great! Nothing found on drivers side of wires loose!

regards
Richard
E30 325i Mtech 2 1990 (Registered in 1991)
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Brianmoooore
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Can't get the first pic. large enough to see properly, but there are no twin blue wires in E30 wiring.
The red and black in the second pic. is also not BMW wiring. It has been added on to the wires that should connect to the lamp that illuminates the rear ashtray, and is possibly for an illuminated gear knob.
I can just make out that the speaker is still in place in the first pic. To access the central locking wires, you need to remove the speaker, then look downwards in the hole it came out of. There should be a horizontal black plastic piece directly below the hole, which just lift out, then below that should be the locking ECU.
Directly below the middle of the speaker, you should be able to see two cross head screws, one above the other. Unscrew these, and the locking ECU, complete with its bracket and wiring, can be lifted out.
The red and black in the second pic. is also not BMW wiring. It has been added on to the wires that should connect to the lamp that illuminates the rear ashtray, and is possibly for an illuminated gear knob.
I can just make out that the speaker is still in place in the first pic. To access the central locking wires, you need to remove the speaker, then look downwards in the hole it came out of. There should be a horizontal black plastic piece directly below the hole, which just lift out, then below that should be the locking ECU.
Directly below the middle of the speaker, you should be able to see two cross head screws, one above the other. Unscrew these, and the locking ECU, complete with its bracket and wiring, can be lifted out.
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RTTBMW
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Hi Brian,
Okay I'll check behind the speaker later today! I'll get better picture of those other wires! I suppose these cars were personalised over the years. Be nice to get it back to original as I can. I wonder can you still get carpets for these cars?
regards
Richard
Okay I'll check behind the speaker later today! I'll get better picture of those other wires! I suppose these cars were personalised over the years. Be nice to get it back to original as I can. I wonder can you still get carpets for these cars?
regards
Richard
E30 325i Mtech 2 1990 (Registered in 1991)
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RTTBMW
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Hi Brian,
The wire in question is white with a blue clear cover, so not sure what that is below! The blue and red wire is blue wire with red spray paint, probably from the time the car was painted!

Here we have the ecu for the central locking you described!

In this picture below you can see the blue /yellow wire has been cut and the green /blue wire has been cut. So let me know what you think I should do next! regards Richard

The wire in question is white with a blue clear cover, so not sure what that is below! The blue and red wire is blue wire with red spray paint, probably from the time the car was painted!

Here we have the ecu for the central locking you described!

In this picture below you can see the blue /yellow wire has been cut and the green /blue wire has been cut. So let me know what you think I should do next! regards Richard

Last edited by RTTBMW on Tue Apr 28, 2020 2:18 pm, edited 2 times in total.
E30 325i Mtech 2 1990 (Registered in 1991)
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Brianmoooore
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I could see someone's been painting around the area from an earlier pic. The limit stop bolt for the accelerator pedal should be unpainted, and yours is bright red.
E30 radios were fitted at the supplying dealer, following detailed instructions issued by BMW. Not all technicians followed these instructions, and I think yours was fitted by one of these renegades. I think I can see a red and white parallel twin cable in the pic, which will be the electric aerial control cable, so the grey parallel twin and the blue parallel twin are probably the rear speaker wires. These should all run down the LH sill.
Anyway, you've found the locking ECU, and as a bonus, you have the interior light delay off option fitted. (the smaller module on the triangular plate.)
Green/blue and blue/yellow are the unlock and lock request wires from the doors (not the boot) respectively, and most certainly shouldn't be cut, although they are the wires you 'tee' into for remote central locking.
Next thing to do is to disconnect the locking ECU and open it up, by sliding its insides downwards. Check it for signs of water damage, and look for a small resistor near one corner, mounted on end, with a small leaf spring beside it, which should be soldered to the top end of the resistor. This is a thermal fuse, which if the locking is drawing current for too long, the resistor heats up sufficiently to melt the solder and release the spring. Note that the solder is a special low melting point variety, and can be resoldered only by using the existing solder. Under no circumstances must any extra ordinary solder be added.
Wiring diagram for the locking (USA version) is here: http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig10.pdf
E30 radios were fitted at the supplying dealer, following detailed instructions issued by BMW. Not all technicians followed these instructions, and I think yours was fitted by one of these renegades. I think I can see a red and white parallel twin cable in the pic, which will be the electric aerial control cable, so the grey parallel twin and the blue parallel twin are probably the rear speaker wires. These should all run down the LH sill.
Anyway, you've found the locking ECU, and as a bonus, you have the interior light delay off option fitted. (the smaller module on the triangular plate.)
Green/blue and blue/yellow are the unlock and lock request wires from the doors (not the boot) respectively, and most certainly shouldn't be cut, although they are the wires you 'tee' into for remote central locking.
Next thing to do is to disconnect the locking ECU and open it up, by sliding its insides downwards. Check it for signs of water damage, and look for a small resistor near one corner, mounted on end, with a small leaf spring beside it, which should be soldered to the top end of the resistor. This is a thermal fuse, which if the locking is drawing current for too long, the resistor heats up sufficiently to melt the solder and release the spring. Note that the solder is a special low melting point variety, and can be resoldered only by using the existing solder. Under no circumstances must any extra ordinary solder be added.
Wiring diagram for the locking (USA version) is here: http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig10.pdf
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flybynite
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Hi Brian
Any idea what is going on with this one? Can't work out what could suddenly be causing this
viewtopic.php?f=2&t=279920
Sorry for thread hijack but it is on topic
Any idea what is going on with this one? Can't work out what could suddenly be causing this
viewtopic.php?f=2&t=279920
Sorry for thread hijack but it is on topic
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ChrisHC
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There are pictures illustrating what Brianmoore is talking about here https://www.e30zone.net/e30wiki/index.p ... king_Relay
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RTTBMW
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These wires are the left hand side of the car. The car aerial still works with the radio! However the radio does not retain the date and time for some reason!RTTBMW wrote: ↑Mon Apr 27, 2020 11:52 amHi Brian,
The wire in question is white with a blue clear cover, so not sure what that is below! The blue and red wire is blue wire with red spray paint, probably from the time the car was painted!
Here we have the ecu for the central locking you described!
In this picture below you can see the blue /yellow wire has been cut and the green /blue wire has been cut. So let me know what you think I should do next! regards Richard
![]()
E30 325i Mtech 2 1990 (Registered in 1991)
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Brianmoooore
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So they are! Was looking so closely at the wires, I didn't notice you'd changed sides.
I doubt if it is the reason for your radio fault, because I'd expect it to affect more than date and time, but check that the red/green wire to the radio is connected and is live all the time.
Most radios have an orange and a red wire to connect to 12 volts+, one permanent live, and one switched live. There's no fixed convention as to which is which, so you could try them the other way around.
BTW, do your interior lights work as they should. The lights should come on as you open the driver's door from the outside, and then stay on for several seconds after the door is closed. When opening the door from the inside, the light should come on, then go off immediately the door is closed.
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RTTBMW
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Okay I will check the radio wires again to see the issue! Yes interior light lights work as they should once I changed the door switch on passenger side as it was banjacked!
regards
Richard
regards
Richard
E30 325i Mtech 2 1990 (Registered in 1991)
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RTTBMW
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I need to remove the door panels to see the condition of the central locking next!
Hopefully tomorrow!
Hopefully tomorrow!
E30 325i Mtech 2 1990 (Registered in 1991)
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Brianmoooore
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Reason I asked about the interior lights is that the delay module shares the same supply (red/black wire) as the central locking, so if this is working, we at least know that the locking ECU is getting power.
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RTTBMW
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Okay, I took both panels off this weekend to investigate the central locking!
While I took off the glovebox beforehand I noticed these wires taped up. What would they be for?

While I took off the glovebox beforehand I noticed these wires taped up. What would they be for?

E30 325i Mtech 2 1990 (Registered in 1991)
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RTTBMW
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Now I removed the ECU from the car and opened it up!
Everything looks normal to me, but I don't have the sharpest of eyes these days, and my glasses keep falling off in this good weather and heat!


Everything looks normal to me, but I don't have the sharpest of eyes these days, and my glasses keep falling off in this good weather and heat!


E30 325i Mtech 2 1990 (Registered in 1991)
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Tzantushka
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Birianmoore will confirm, but looks like that component in the lowest LH of your picture is the thermal cut-out fuse which has melted (as it should) and opened the circuit.
See pic from the Central Locking Wiki

See pic from the Central Locking Wiki

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RTTBMW
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I peered into the passenger side to see the actuator still in there. Drivers door was the same too!



So all seems to be there! So why would this not be working apart from the cutting of a few wires?
regards
Richard



So all seems to be there! So why would this not be working apart from the cutting of a few wires?
regards
Richard
Last edited by RTTBMW on Wed May 06, 2020 11:47 am, edited 2 times in total.
E30 325i Mtech 2 1990 (Registered in 1991)
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RTTBMW
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Sorry I just noticed your reply! Is it meant to be soldered to the wire and the top of the resistor at the same time?Tzantushka wrote: ↑Mon May 04, 2020 10:47 amBirianmoore will confirm, but looks like that component in the lowest LH of your picture is the thermal cut-out fuse which has melted (as it should) and opened the circuit.
See pic from the Central Locking Wiki
![]()
E30 325i Mtech 2 1990 (Registered in 1991)
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RTTBMW
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RTTBMW
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One thing that does bug me is the drivers door and passenger door are stiff to lock and unlock! Would that be becasue of the actuators still connected!
regards
Richard
regards
Richard
E30 325i Mtech 2 1990 (Registered in 1991)
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Brianmoooore
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The insides of your locking ECU look nice and clean, with no sign of corrosion or water damage, BUT the thermal fuse in the corner has clearly tripped.
This is NOT a fault in itself, but an indication that the locking ECU was overloaded, and the protection arrangements worked as intended.
Next thing to do is to resolder the spring, but it's very important that you don't add any solder, especially the lead free rubbish that's around these days. The existing solder is a special alloy with a very low melting point, much less than that of ordinary solder, even the better stuff with lead in it.
When this is done, plug it back in, and see what happens, but if the locks sound like they're sticking and the motors stay buzzing, unplug it again quickly, before the thermal fuse trips again.
This is NOT a fault in itself, but an indication that the locking ECU was overloaded, and the protection arrangements worked as intended.
Next thing to do is to resolder the spring, but it's very important that you don't add any solder, especially the lead free rubbish that's around these days. The existing solder is a special alloy with a very low melting point, much less than that of ordinary solder, even the better stuff with lead in it.
When this is done, plug it back in, and see what happens, but if the locks sound like they're sticking and the motors stay buzzing, unplug it again quickly, before the thermal fuse trips again.
The locks are always going to be stiffer if the central locking isn't working, because the lock motor in the lock you are turning with the key normally assists in a similar way that power steering does with the turning of the steering wheel. That said, if the mechanism is really stiff, after 30 years of no lubrication, then that just could be the cause of the thermal trip opening.
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RTTBMW
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Just thinking I did not check the boot lock or the fuel door for parts! I suspect these could be missing as the whole rear quarters and inners were replaced about 6-7 years ago!
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Brianmoooore
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Wouldn't affect the operation of the rest of the system.
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ChrisHC
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Yes that strip of spring sticking up vertically needs to be held against the top of the resistor and soldered on. It looks as though there is a fair bit of solder there to use, if not it is possible to buy low melting point solder online, but ordinary solder must not be used.RTTBMW wrote: ↑Mon May 04, 2020 11:51 amSorry I just noticed your reply! Is it meant to be soldered to the wire and the top of the resistor at the same time?Tzantushka wrote: ↑Mon May 04, 2020 10:47 amBirianmoore will confirm, but looks like that component in the lowest LH of your picture is the thermal cut-out fuse which has melted (as it should) and opened the circuit.
See pic from the Central Locking Wiki
![]()
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RTTBMW
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Well I just checked the car for the fuel lock and boot actuators. All seems to be in place! I'll solder that back on this week and connect up those few wires that are cut!


Boot lock actuator!


regards
Richard


Boot lock actuator!


regards
Richard
E30 325i Mtech 2 1990 (Registered in 1991)
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RTTBMW
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What is the best oil to lubricate these locks so they have little resistance to opening, so I minimise blowing the solder again?
Richard
Richard
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Brianmoooore
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It's ordinary LM grease that's required, not oil, and to do the job properly, any old hardened stuff needs to be removed first. This especially applies to the driver's key barrel assembly, which really needs to be removed from the car (big C clip) to get it working as it should.
Since you've dug your way into the fuel and boot lock motors, you may as well unplug them for the initial tests, just to reduce the number of potential problem sources.
Note that the locks won't set if the driver's door is open (they'll lock, but immediately unlock again), and fully open a window first, just in case the ECU decides to lock you out of the car permanently.
Since you've dug your way into the fuel and boot lock motors, you may as well unplug them for the initial tests, just to reduce the number of potential problem sources.
Note that the locks won't set if the driver's door is open (they'll lock, but immediately unlock again), and fully open a window first, just in case the ECU decides to lock you out of the car permanently.
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RTTBMW
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I tack soldered the thermal cut out fuse without even adding any extra solder so all good so far!
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RTTBMW
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I’m a little confused at the minute. See pics below. I was about to wire up the grey/green wires together but realised they aren’t connecting to anything but has a white plug connector. Taped up going no where. The yellow/blue I can’t find where it is to wired back to.


I need someone tell what have I missed. At the top of the first picture is a white square connector. What was that meant to be connected to?
Regards


I need someone tell what have I missed. At the top of the first picture is a white square connector. What was that meant to be connected to?
Regards
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RTTBMW
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I’ve struggled to get the c clip off. Seems to turn easily though.


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RTTBMW
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I took the connector off from the A pillar. Slight paint over spray on connectors. One slightly corroded. Red and black wire one.




E30 325i Mtech 2 1990 (Registered in 1991)
