Nik_Lee
This reminds me I think I forgot to send you the details on the solid state relay I have been using in mine. sorry about that.
I am using a Stinger SGP38 80 Amp Battery Isolator and Relay here is a link to one and I have also seen a couple of electronics stores on ebay selling them.
https://www.elite-electronics.com.au/In-Car_Entertainment/Accessories/Capacitors/Stinger_SGP38_80_Amp_Battery_Isolator_and_Relay
It's OK, a few weeks ago I found this thread where you included the same product link:
https://www.mr2australia.com/mr2play/tm.aspx?m=122053However, I was confused because I thought that you were using a solid state relay. As far as I can tell, the Stinger SGP38 is NOT a solid state relay. I think it's still a mechanical relay, but I'm sure it would do a much better job of handling the required current in comparison to the original power steering relay.
Knightrous
https://www.jaycar.com.au/solid-state-relay-4-32vdc-input-30vdc-100a-switching/p/SY4086
Yep, you gave me that link a while ago, thanks! I am leaning towards that solid state relay. The only potential downside is that solid state relays get hot and in doing so their maximum current reduces, so I need to make sure that the heat can be dissipated. I think it should be OK with it bolted straight to the metal chassis of the car anyway.
BTW, when I was talking to you about it you mentioned that I'll need a diode to suppress the EMF spikes, but it occurred to me that the factory power steering driver unit probably/hopefully already has a diode for this purpose.