Why would someone bypass a perfectly good radiator temperature switch?

I've been fiddling under "Graham's" bonnet.
The primary task was to sort out the rad temperature switch that was bypassed.
I assumed that the rad switch was broken - hence the bypass with a switch on the dash.
I restored the wiring back to the original then shorted across the rad switch connector and the fan came into life.
Then drained the radiator to get the old switch out.
The coolant was green without oil or rust - a good sign.
I took off then fan so I could get a big spanner on the rad switch. It would be handy to have a deep socket for the job.

Before I fitted the spare, I thought I should test it.
I clipped an old speaker lead to the spade connectors of the rad switch and put the switch in a pan of water on the cooker. When the water was boiling the switch made contact OK. I let it cool down and heated it up again and it worked OK.

:idea: Then I thought I'd test the old one and it worked too.

So if the old switch worked, why did they bypass it? :bang:

C.T.

There are many strange people in this world and that question could have a myriad of answers.

Maybe they were bored one afternoon and just fancied trying? Strange one.

Failure or suspected failure of thermostat or suspected head gasket failure ? For someone to go to the effort of wiring in a bypass, there must have been a reason.
Rgds.

So what do you think I should do?
1. Restore it to the original?
2. Use both together in parallel?

I'm worried there may be something strange lurking yet to be discovered.
Though I can't think what.

I noticed that the rad fan fuse has been changed, as it is a solid white 25amp.
(All the other fuses are the, original, translucent plastic.)
So perhaps the fuse went and someone didn't realise and bypassed it.
The bypassed wiring is only live when the ignition is on. So it won't cool when the engine is off.
:idea:
I think I'll restore it as it should be and see what happens.
C.T.

Agreed, restore to original but do not take the bypass wiring out until you have proved the system.
Rgds.