I have fan issues but it is more 19 yr old girls that stalk me!

I would first check the earth or wire a new earth, many cossie looms get corroded at this age. Rod Tarry could build a new loom and that would solve lots of future probs. you can get new sensors that are stand alone and cut in to the pipe work from demon tweets with their own relays etc. You can also wire in a 30 amp relay to manually over ride or buy a stack gauge that has a control.

If in any doubt just call a mobile auto electrician