Can Anyone Help with this Relay?

I've got a Boomslang Harness, but my headlights have stopped working. I've previously had an issue with the right hand relay

One of the terminals corroded and overheated, slightly melting the relay holder. The headlights went off. Cleaned the terminals up and all good. They've gone off again, so I've changed the fuse holder for a new one. This did not cure the problem.
I've tested the relays and they switch when I apply 12v. This creates continuity across the other terminals.
I've tested the switch on the steering column and it seems good. I'm not getting 12v at the headlight connector though. This connector plugs in to the boomslang harness and is supposed to make the magic happen.
The left hand relay works when you pull the main beam lever. It clicks and the main beam comes on! I'm not convinced the right hand relay is broken, but H5458 gives me nothing on Google. (Other than pictures of boomslang harnesses) Can someone tell me what the relay is? Is it a 'change over relay' like this one? https://www.autoelectricsupplies.co.uk/product/174/category/36

Yep, looks the same to me - should be loads on the bay too...

have a nosy at item # 262397420942 ..... also same ....

I just searched for 12V auto relay - sure the zone will have em too ....

edit to add:- zone item "number" :- B07BK4DBPB

Think what you're looking for is a SPDT switching/changeover relay

Disco1BFG said:

have a nosy at item # 262397420942 ..... also same ....

I just searched for 12V auto relay - sure the zone will have em too ....

edit to add:- zone item "number" :- B07BK4DBPB

Click to expand...

Cheers, mate. If I'd searched 12V auto relay, I wouldn't know what I was looking at.

Al2O3 said:

I've got a Boomslang Harness, but my headlights have stopped working. I've previously had an issue with the right hand relay
View attachment 248851
One of the terminals corroded and overheated, slightly melting the relay holder. The headlights went off. Cleaned the terminals up and all good. They've gone off again, so I've changed the fuse holder for a new one. This did not cure the problem.
I've tested the relays and they switch when I apply 12v. This creates continuity across the other terminals.
I've tested the switch on the steering column and it seems good. I'm not getting 12v at the headlight connector though. This connector plugs in to the boomslang harness and is supposed to make the magic happen.
The left hand relay works when you pull the main beam lever. It clicks and the main beam comes on! I'm not convinced the right hand relay is broken, but H5458 gives me nothing on Google. (Other than pictures of boomslang harnesses) Can someone tell me what the relay is? Is it a 'change over relay' like this one? https://www.autoelectricsupplies.co.uk/product/174/category/36

Click to expand...

Just make sure you get the correct rated relay. Should be 40A

(my high beam failed yesterday & Mrs said it took a few seconds to realise to turn the high beam off to get normal lights was scary)

The relay on the right is a change over relay, as shown on the relay casing diagram.
The relay on the left is a non-change over relay, again shown on the relay casing diagram.

If not sure see how many pins the relay has, 4 = on/off relay, 5 pins = changeover relay. you can of course use a 5 pin in the place of a 4 pin.

Use the relay as a center point, find which side is at fault before striping switches or connectors.
Do you get a switched 12v when required on terminal 85 or 86?
If so your switch is good
Do you have a feed to switch on terminal 30?
If so short it to 87 to simulate the switching of the relay.

Thanks for all your advice gents, much appreciated.
I've been back at it. Disconnected the two boomslang connectors from the two headlights and connected the standard ones. Headlights worked straight away
Took them off again, plugged one of them back in to the boomslang (one original connector acts as the trigger) and the two boomslang ones back in to the headlights. Bingo! Headlights worked through the boomslang - no idea how that sorted it.

When I first fitted the harness @nobber asked how the voltages had changed, but I didn't measure them at the time. Did this time though
With engine off:
Voltage at original headlight connector 10.56v
Voltage at boomslang connector 11.85v
Voltage across battery terminals 12.08v

Don't think my battery is in great condition!