Fan switch - thermostat

Hi all you lovely folks,

My poor van overheated recently  I have been told it needs a new switch/thermostat as the fan fails to cut in when the engine gets hot, stuck I traffic etc.  Has anyone wired a manual switch, placed somewhere on the dashboard to manually turn fan on when needed, ie. stuck in traffic etc.  Any help would be great, hope ive explained it adequately.

Cheers,

M1strals

Have you tried cleaning the contacts on the fan relay switch?
It is quite susceptible to corrosion.

Having a manual switch is a common addition but you need to make sure there is no underlying issue that would have caused it to overheat sooner than it did. Try cleaning the contacts as suggested first.