I have two relays that I want to close with a single closed circuit.

So I though I could connect the relays in series. I thought it made sense. But it appears not so.

If I connect ground at “X” and apply live to point “A” I can close switch 1. But it doesnt close switch 2.

If I apply live to point “B” I can close switch 2, but not 1.

Is there electrcikery inside relays effectively preventing this from working as I think? Obviously I just need to connect them in parallel instead, but just wanted to check.

Cheers for any pointers.

Is b earthed somehow?

if they are 12V relays you;d just be best to connect the relay supplies to 12V in parallel, the switching side can still be in series if that is important

I’m surprised either of them work, you’re only dropping 6v onto a coil which needs ~10v minimum to close the relay!

Thinking about it, I’ve never seen relays wired in series like this (on ships), 1 relay would surely do what you’re trying to achieve in that picture?

I’m surprised either of them work, you’re only dropping 6v onto a coil which needs ~10v minimum to close the relay!

Mwah. Love you.
I was being dumb and didnt really twig that it needs the full voltage to work!

Thanks. Will wire in parallel.

Chuffed that my heated windscreen test rig with a 10m timer works perfectly. momentary live for on, momentary live for off, or 10m delay auto off!

I need 2 relays as I need 2x 30A, one to each side of the screen.

Ah right, so switches 1 and 2 won’t be wired in series like in the picture?

good point. no they wont.
Although for the purposes of the illustration it doesnt matter.

Jaysus! Put a fuse in the line would ya… I take it you’ve never seen a shorted cable of that size connected across a battery of that size!
You don’t get much chance to stop it manually!