603 - electric windows

[Peter Hoskin]

I found the drivers switch for the passengers window stuck in the up position and the window was firmly closed and would not respond to either control switch. The drivers window operated normally. I changed the drivers 2 switches over so the previously stuck switch now operated the drivers window which it did so correctly. ie fault not in that switch.
I tested the window winder motor by direct connection from the battery and it operated the window up and down correctly. ie motor not the problem.
I removed the two Circuit Breakers, they appear to be sealed units, I assume they are overload devices that work on excess current (what Value?) and auto reset. Neither was in an open circuit state so I assume OK?
I have followed the wiring diagram and colour coding shown in the expanded diagram by a Mr C R Foster dated 17/09/99, which I checked against the more difficult diagram in the Drivers Handbook.
I am getting 12+ volts at both switches.
Any suggestions as to what I do next

[dwomby]

I am sorry if you already did this but have you checked continuity of all wires between the switch and the motor?

I don't have a 603 but imagine there are a few connections along the way.

David

[David C]

Are you able to post a copy of the diagram?

[David C]

Just found a schematic.

Are you able to swap out the passenger side switch with the driver's window switch?

As the driver's side switch for the passenger window is used at rest to supply power to the passenger side switch, both switches need to work to allow operation. You have tested both switches on the driver's door but seemingly not the switch on the passenger door.

It looks as though the breakers for the driver's side are in the positive line but those on the passenger side are on the negative line.

With all switches at rest it looks as though both motors have +12V on both wires relative to ground.

Let us know if you are still struggling and I will try to do diagrams showing current path for each option of switch operation.

[Peter Hoskin]

Very helpful responses to date.
Continuity of wires... I have checked about 30 different cable linkages but I cannot find a record of testing between the motor and the switch so will do so starting with the SR and SU in turn but have difficulty in understanding the circuitry, I presume if SU supplies voltage then SR is returned to earth? via Ru? and then supply to RU operates the window in the opposite direction?
I have not swapped the passenger two switches as I assumed fault on drivers side. Will do that.
I am trying to send a copy of the wiring diagram but it will not transfer altho I have reduced to below 1 MB. will keep trying.
sorry, not successful

[David C]

Understanding what the switches do is the key.

The motor is fed from the middle contacts of the passenger door switch. In its rest position the driver's door switch for the passenger window simply passes positive supply volts to the passenger door switch.

I have had a go at uploading images but only managed thumbnails. If someone can explain how to attach full size images I will try to make a better job of it.

[Kevin H]

Originally Posted by David C

I have had a go at uploading images but only managed thumbnails. If someone can explain how to attach full size images I will try to make a better job of it.

David,
Your uplaoded images are okay; only the thumbnails are shown in the post, but if anyone clicks on the thumbnail they will see the full size image.

The wiring diagrams are in the Resources section of the site here Resources - Bristol Cars - Owners and Enthusiasts Forum

Kevin

[Kevin H]

Originally Posted by Peter Hoskin

I am trying to send a copy of the wiring diagram but it will not transfer altho I have reduced to below 1 MB. will keep trying.
sorry, not successful

Peter,
If you are trying to upload the wiring diagram, the size limit for most image file types is actually now 2Mb. But feel free to email to me and I will upload them if required - webmaster@bristolcars.info

Also, there are wiring diagrams available in the Resources section of the web site here

Resources - Bristol Cars - Owners and Enthusiasts Forum

Kevin

[Kevin H]

I haven't had any time to look into this issue or check the wiring diagrams, but are there any microswitches which detect the upper or lower limits of the window travel?

[David C]

Thanks, Kevin. Is there a way to get the images into the body of the text?

[Kevin H]

Originally Posted by David C

Thanks, Kevin. Is there a way to get the images into the body of the text?

It may be possible but the forum software is not configured to facillitate this. One of the reasons for this was because the system did not auto-size the photos so we were getting massive images in posts which distorted how the posts displayed.

Maybe in the next version of the site if I can ever find the time to update it!

[douglas j]

I had no end of trouble with the windows, there is a cut off switch in the door which I came upon, this may be the problem. The switch stops the window when it reaches the top and it may have cut off the supply completely. If the switch on the doors are faulty you can use a universal rocker switch which looks almost identical and are readily available. Quite a bizarre way of wiring but probably typical.

[Peter Hoskin]

Thanks for all the responses.
Wiring diagram - drawing B680039 shown on the resources website quoted by Kevin is the one I am using. It agrees with the one in the handbook including colour coding.
Switches: I swapped the drivers window switch with the passenger's side window switch. Neither worked their respective windows. I swapped back and restored use of the drivers window. Conclusion-the passenger switch at fault but also a further fault in the circuitry.
Stripped the passenger switch- I rebuilt one several months back and this one seemed different. In this switch one of the floating copper bars is firmly rivetted to the connector at one end. I seem to remember on the previous rebuild these 2 copper strips were both floating? I cleaned contacts and re-assembled re-installed and did not work. Without any particular reason I connected the firmly rivetted end to BR at the 'down' end?
Micro switches- there are no micro switches, there function appears to be replaced by the circuit breakers which would appear to be current overloads that auto. reset? Neither showed an open circuit so I assume are serviceable?
Thumbnail of switch circuits- I will study these more closely and could find I have connected the passenger switch incorrectly.
more research necessary, it looks as if we will be attending the BOCA Rally in Victoria from 27 March without an openable passenger window!

[Kevin H]

It's 20 years since I did some work on my 411 windows, but I recall that both passenger and driver side switches had to be connected, not sure if they were interchangeable. I do recall removing mine from the armrest and reconnecting them with the door trims removed.

I can't remember whether one of my windows didn't operate or whether it was painfully slow, but I know I rewired them with good quailty heavy duty wire and replaced all the bullet connectors. This made a significant difference.

Peter, have you had a voltmeter on the motor terminals while you operate the switch? I'm just wondering if the issue is insufficient current.

Also, re the circuit breakers - you said they were not open circuit, but was this with power on them and the switch operating? If they are current sensing circuit breakers (which is likely) and the motor is trying to draw too much current, the circuit could be broken momentarily whenever you try to operate the passenger window. You could perhaps try bypassing the circuit breaker with a peice of wire with an inline fuse of a suitable value (20-30A?)

[Peter Hoskin]

Thank you Kevin, I will follow up your suggestions when I return from our forthcoming Rally. I have not time to conduct major work at present. I tested both passenger switches when in the idle position and in each case I found each terminal on both switches had 12+ volts!
I am expecting new switches and circuit breakers from Graeme Payne in the neartime so will be in a better position to conduct further testing.

[David C]

If you take a look at my sketch below you will see that +12V on all connections is very nearly what you need. It is only the top right connection on the left hand switch in the sketch that provides earth and causes current to flow.

[David C]

If you have +12 volts supplied from the driver's side switch then the circuit for the passenger switch can be simplified as in the attached diagram.

The best tool for fault finding will be a 12V bulb that draws a few amps of current. A digital multimeter may give misleading readings as it won't put any load on the circuit.

[Peter Hoskin]

Sorry for the break in communications, we had a successful BOCA Rally in the Victorian Alps followed by a couple of days in the Snowys.
I received and fitted to the passenger door a new switch, it did not work but did restore to working the drivers switch! progress!
Circuit breakers-in request for replacements I received cut off switches which have a 411 no. but of no use to me but following Kevin' s comments I applied brain and realised my logic was wrong. I assumed that an overcurrent sent the circuit to earth whereas it breaks the circuit to earth. Makes sense.
I attach a sketch of the connections on the new and old switches. The new switch corresponds to the connections shown on David's sketch except my Up and Down appear reversed. I have shown the connections with colour codes, the wiring diagram does not show which is the UP or DOWN end of the switch - can anyone enlighten me? I assumed the BY wire goes to the DOWN end of the Passenger switch?

[David C]

Can you confirm what you now have? It sounds as though the driver's window works as it should. Does the passenger's window operate from either switch?

The switches are symmetrical so, unless they have any markings, they will be fine either way up.

[David C]

Per my post of 22nd March, if all is well on the driver's side you will have 2 x 12V supply and 2 x earth on the passenger switch. Check on the passengers switch with a meter that the 12V doesn't drop to nothing when the switch is operated. If it does then you have a high resistance in the wiring or the driver's door switch.

You can use a sealed beam headlamp bulb with flying leads to test that you have good supply and earths. It will draw about 4 amps which will be enough to show up any high resistance in wiring or switch.

Assuming the feed to the windows is fused you can very briefly test with the breakers bypassed to earth, although I doubt the breakers are at fault unless you have bad enough luck that they have both chosen to fail at the same time.