Fan Switch!

[erbs 42 1 Cars]

another prob found.

 

where is the radiator fan switch usually located?

 

also which is the best way to test the fan?

[johnnyboy666 195 1 Cars]

It's a temp sensor switch, plugged into the radiator itself, quite common for them to fail. Theres different types that kick in at different temperatures, so bare that in mind when sourcing a new one. Or some people bypass it completely and run wires to a switch in the cabin, can be handy, but also a pain!

[damien 22 1 Cars]

dont want to sound rude but a search would help you.

 

the switch is on the top right (battery side) of the rad.

there is a brown plug somewhere on the loom to the switch, you can cross 2 termals on the plug which will turn the fan on

[welshpug 1,677]

if its a phase 1 it can be found on the right hand end of the rad near the bottom hose, but all later ones are just under the top hose.

[erbs 42 1 Cars]

as welshpug said on the top right, i replaced the fan switch and now comes on and when engine is turned off the relay is working too as the fan keeps spinning

 

just sorting out the mechanical's 1st so i do apologize for asking questions, i do look in the search but its usually just off the mark of what i need to know

 

i got a like for like switch as my one has a red band around it so it comes on at a certain temp but thanks for helping me

 

just one other question

 

what are the silver like cylinders that sit around the front of the engine bay do?

[welshpug 1,677]

there's no relay on single fan arrangements, its a permanent fused live running directly through the thermoswitch.

 

the silver cylinder is a resistor for the low speed, there's also one under the n/s headlamp for the dim dip headlamps.

[lagonda 42]

One of the cylinders is the resistor for high/low coolant fan speed. The other is the headlight dim/dip resistor.

 

In my experience, it's usually corroded connections that stop the fan working, rather than a fault with the sender unit itself. Originally the terminals on my sender needed cleaning, then more recently, it was the earth terminal (one of those in the yellow block near the n/s headlight.

[erbs 42 1 Cars]

well i did all that, i cleaned the terminals on both the switch and the plug but still nothing so i decided to test the loom and just bridged the terminals and the fan came on, so when i run it up to temp

 

the fan should come on but nothing happened so the last resort was to get a new switch and when i replaced it, the fan came on when the engine was hot so i think that the switch was at fault in

 

this case, it was the original switch and being 21 years old i kind of suspected it be that so just to be sure i just tested it