The Lotus Grand Tourers

When the ignition is switched to pos. 2, the 2 fans will cut in, regardless of the temp condition and will stay on untill I pull the key!

I have pulled the connectors on the OTTER switch and the fans will not cut in anymore. Turning the a/c on will force the fans to run.
So it is very likely that the OTTER swich is dead (again)!

How can such an expensive piece (o.s.) break so often???
On top of that, it's hard to replace, also...

Yeh, I've had a couple on my Excel in 10 years ... luckily the engine management system for the fuel injection will soon take over fan control!

Same issue here (yet another on the long list of faults) - I've been toying with the idea of replacing the standard otterswitch with one of these : http://www.merlinmotorsport.com/index.p ... =1683_2113 or one of these https://secure.visav.co.uk/avshop/produ ... witem=1487

i had the same with the old engine in my car, the fans staying on... aws far as i know, it is a simple bi-metallic strip, that switches at he corrent temperature, unfortunately due the fan motor, being sooo torquey, it draws too much current, so it fuses on, maybe a capacitor could stop the arcing across the terminals...

Phil

I think a Saab one fits straight in. Lotus obviously didn't unstand ohms law as much of their electrical plumbing leaves much to be desired especially in the reliability department. I am removing all hi current switched circuits from within the car, so lights, motors etc all getting a new power feed and relays.

I'm pretty sure my car has a relay for the fans, I thought they all did! It still doesn't stop the damn switch packing up and it must only be switching a few hundred milliamps!

The otter switch is one of the first things I've ditched on every Lotus I've owned. My Excel runs a (Hyundai) Excel screw fit switch with some basic plumbing fittings I picked up at the hardware store. Honda ones are fine, as are VW Golf ones, it's just a matter of adapting something to fit in the existing housing, or making up a new threaded one. You can't braze or solder anything to it, in my experience.

Robert

Hi Guys,

thank you all. I will leave the switch disconnected for the time being, as it is still cold outside and the engine will hardly reach temperature these days. In case of an emergency, switching on the a/c will force them to cut in.

Roy, methinks 15 quid is still too much for an item which tends to go south regulary...

I think I will upgrade the switch in spring, as many of you have suggested.

Thannks

JB

Just checking (since I can't get to my car at the moment) - what's the diameter of the top hose ?

Hmmm - According to the SJ Sportscars parts list, the otter switch changed from a M22 fitting to a M14 sometime in 1990, around number 3007. Mine is 3036 (and, I hope, currently up in the air getting a new diff cover gasket fitted)!

I think I'll get one of the Pacet capillary thermostats from Burton Power and see how that works - it should be possible to insert it without having to let too much coolant out and reports elsewhere suggest that the pad kits supplied result in a good seal around the hose junctions so there shouldn't be leakage around the capillary tube.

I'll post the results of my "experiment" here (in technical articles perhaps ? Time we had something in there) for all to see.

I have been running with a Scimitar SE6a from Graham Walkers for around ten years now and no problem.

Suggest you check to ensure the correct relay is being used. If a higher rated one is being used, it could be drawing too much current and that could be the cause of the Otter switch burning out. Why not measure the current being drawn through the otter swich.

Nick

I think that the reliablility of the sensor is down to how it is fitted, the sensor is located just where all the water from the bonnet goes down, and when I got my car its sensor had the wires comming out sideways and the water was just washing over the guts of the sensor. so when I fitted the scimitar one I sealed the connectors and most importantly pointed it down so any moisture will drip off.

just a thought

Ian

Ordered the Pacet electronic capillary switch from Burton yesterday - it arrive today. Fitting it tomorrow.......

Pacet adjustable capillary sender fitted - works very nicely as a plug-in replacement for the original and the adjustable temp. range means I can tweak it for local conditions

Anyone interested in some photos of how it looks and a description of how I fitted it ?

Yep Yep

Phil