Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Fan Speed Knob

That’s more like it!
Only comment is that if it’s going to be mounted behind the dash, it might be wiser to go for the fully enclosed version to protect against the infamous Morgan water leaks, which is what has wrecked many of the original pcb installations.

In the end I went with this one for £11.00 from a UK seller:



* Internal forward & reverse relays so the original Lorlin 1a rotary fan switch can be used

* Easy to wire in the original fan switch

* Remote pot

* Rated 40a (30a continuous)

* Vented enclosure

Obviously I just need the forward circuit, but the forward and reverse versions use relays which I prefer given I want to use the original Lorlin 1a rotary fan switch.


Search eBay item number: 204515866552

Hi Rog,

Is the stop something that can be adjusted by me, or is it set when the switch is manufactured? and hence why I need a new switch.

Have been looking at new switches and it also looks like I need to know if the current switch is "Make" or "Break" before make, does anyone know which it is.

Thanks

Yes you can adjust the stop. It’s the little tab here that you poke in the appropriate hole.



My switch looks to be a Lorin and here's the data sheet. There are lots of other options here.

I’m sure the electrical wizards will confirm, but perhaps if you used a 3 pole 4 way, you could use all the pole contacts and maybe have triple the 1A @ 24V per contact current rating? Depending on your new fan load, you might save yourself a relay?

For reference, here’s the back of mine.

Thanks Rog,

That looks really simple to do.

So forgive the next stupid question.

Could I connect 2x Poles together to make a bank of 6 position that would share an earth and then limit to the 4 positions I need? or is there some electrical rule that says this is not a good idea?

So it's appears to be a wafer switch allowing up to 4 poles and up to 12 way but not both. Also an adjustable mechanical stop.

The data sheet suggests different wafers are needed to achieve the various combo's. As Morgan OE it appears to be set up for single pole 12 way (make before break) with the mechanical stop set at just three 30° position increments. Does this sound correct Rog?

If so then Mark would need a different wafer or most likely order a different switch combo from your eBay link, as 2 pole 6 way is an option.

It does appear that having the four pole, three way wafer the poles and corresponding contacts could be paralleled up to give 4 amp rating...... maybe

If I understand the question correctly, it can't be changed. There are 12 positions with 4 poles, each pole having 3 ways or contacts. The number of ways is fixed by the switches wiper geometry. However, the number of positions can be reduced using adjustable stop



I think Mark needs 4 ways/positions so maybe only 3A?

I hope that I have my poles and ways the right way around

Thanks that's exactly how I understood it Rog

So in answer to Mark you can order a new similar two pole six way switch via Rog's eBay link and put the mechanical stop at fourth position. You would need to parallel up both the poles and the respective four way contacts though to take advantage of the increased current rating.

Here is the knob on my 2014 Roadster showing the connections. It is bottom left of the 3 controls. Also note the bowden cable connector & quadrant

Dave, is that a bi directional pot? If you swapped it for a regular single direction long shaft pot, with a switch incorporated, it might all fit neatly in place of the Lorin switch. Then you would have full control using the standard knob.