603 - electric windows

[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.