relays

Hi. Does anyone know why if there is power into the heater relay, there might not be any signal out of it, brAND NEW RELAY too! Ignition signal doesn't come live into relay(should it?), fuse does, earth good. Got a diagram f some one can briefly describe how it works, i'll work with that.
thankx a lot
undark

Hi Undark,
Relays are only switches that are operated by electricity. When you apply power to the coil the contacts make the circuit of whatever you are operating. At the same time double throw relays can be used to break a circuit when they are energised. I suspect you have a single pole relay. If it clicks when power is supplied and you are not getting any power out of the contacts, it is because there is no feed to the contacts that you are operating. To recap, you need two supplys. 1 to power the coil that operates the contacts and 2, to supply the item you wish to switch on.

Hope this makes sense.

thanks rewmer, useful stuff. I managed to fix the heater and the rear demist and the rear wiper, but this keeps blowing fuses, again the relay I think. Does anyone know the location of the relay for the electric mirrors and the rear wiper? cheers
undark