Lotus Elan and Lotus Elan Plus 2 Forums

I have always been under the impression that there are no limit switches on the winder system, and as such, have always been careful not to try to get the glass fully up into the top seal. However, when looking at the gearbox with the cover removed, there does appear to be some sort of switching in there.
Informed information required before I reassemble the motors.

Hi Brian,

like you I always thought there was no limit switch as the motors were slightly modified window wiper motors from an Escort. From my ammeter they keep drawing current when at full travel, so there does not seem to be a (working) limit switch on my ones.

Not had one apart but could the switching be the remains of the original self parking mechanism?

Hi Brian,
The slip ring in the gearbox was used to achieve self parking in it's original role as a wiper motor.
In that application the motor ran in one direction only powered via the two wires which enter the motor case itself, brown/green +12v and green earth. The brown/green was permanent live and the green wire was earthed via the wiper switch when running, when switched off the earth connection was maintained via the second green wire through the slip ring in the gearbox until the wipers reached their park position. There would have been a wire from the other end of the slip ring to the spade connector on the outside of the gearbox which is not present in this application. Here the supply and earth wires are connected directly to the window switch which reverses the polarity to achieve raise/lower operation.

Thank you, Roger - excellent explanation.

i worry about the risks of these motors drawing too much current, particularly as they are not fused in the standard set up. i see that Maplin sell 'self resetting thermal fuses' in various current ratings. Their blurb says 'A range of compact circuit breakers with an auto-reset facility. Designed to withstand overload but to trip quickly on short circuits, the circuit breaker latches into an ?off? state under fault conditions and automatically returns to the ?on? state after a set period of time. If the fault condition still exists, the unit will immediately latch ?off? again. This process of checking the circuit will continue until the fault is cleared. The range is suitable for working at voltages up to AC 250V, and offers seven rated ?holding-current? values. Connections are via two solder tags 7mm long. Overall dimensions: 29 x 12.5 x 6mm. Supplied individually in the following ratings: 1.0A, 1.6A, 2.2A, 3.0A, 5.0A, 7.0A, 10.0A.'.
At under ?2 a go, they sound like a worrthwhile investment to me, but i haven't tried it and don't know what current rating to choose.
Richard

This is the type of cut out fitted to later vehicles.

http://www.ottercontrols.co.uk/sectors/ ... ction.html

Regards
John

I was unaware of that, John. do you have any details of what it looks like and where it is fitted? i can't see it on my 1973 Sprint.
Richard

Hi Richard

Sorry, my post was misleading. The Otter cutout was not fitted to Elan or +2 as far as I know but was fitted to other makes of car of later manufacured mid to late 70's to get over the current draw and subsequent damage when the window is fully closed, as soon as the thermal switch heat up it cuts out and this protects the motor, wiring and window control and then resets automatically as soon as it cools.

Sorry for the confusion

Regards
John

ricarbo wrote:i worry about the risks of these motors drawing too much current, particularly as they are not fused in the standard set up.

I sholdn't worry, I just held my finger on the switch - stalled current is about 2A, so at 14v that is 28W.

AHM wrote:

ricarbo wrote:i worry about the risks of these motors drawing too much current, particularly as they are not fused in the standard set up.

I sholdn't worry, I just held my finger on the switch - stalled current is about 2A, so at 14v that is 28W.

I think stalled current is typically a lot higher than 2 amps, my motors draw around 2.5 amps to raise the windows, 1.5 amps to lower and off the scale of my 5amp meter when stalled. Others have found in excess of 10 amps. See this previous thread on the subject.....
elan-mods-f31/window-winder-motor-t24850.html
Maybe you have a bad connection somewhere in your circuit.

oldelanman wrote:Maybe you have a bad connection somewhere in your circuit.

Yes, probably, my ammeter is built into the car, as are all of the resistive connectors, switches, and wires. I rely on the bloke who designed and speced it knwowing more than me.

What are the characteristics of your battery charger under load?

Well, looking at those current readings, I think I'd choose the 5 amp self resetting fuse and install it inside the gearbox of the motor, if there's room. I might take my finger off the switch as soon as the window is fully up or down, but I can't expect my passenger to do the same.
Richard

AHM wrote:

oldelanman wrote:Maybe you have a bad connection somewhere in your circuit.

Yes, probably, my ammeter is built into the car, as are all of the resistive connectors, switches, and wires. I rely on the bloke who designed and speced it knwowing more than me.

What are the characteristics of your battery charger under load?

Good question, I have no idea - it gives 14.4v offload but I can't check what it drops to under load as the motors are back in the car now.

I just checked my motor current again using the ammeter in the car (not very accurate I know) and with a fully charged battery the gauge barely moves off zero with the motor running but jumps to just above 10 amps when it stalls.