Strange noise and negative triggers

[Parksy]

Hi all, I have 2 questions.

First is I have a strange noise coming from the back of the patrol after I switch off. After about 5 mins of switching off, a strange buzzing noise appears to be coming from around the fuel tank, maybe the fuel pump? Do they normally do this? It only lasts about 10-15 seconds and that's it. Noise gone. Engine is an efi unit. 4.2l.

Second question, I'm about to install an alarm into the patrol and the door trigger needs a negative trigger? Does the switch on the open/close switch give me this negative trigger or will I need to wire a relay off the cabin light to achieve this?
Where is the most accessible point to reach the cabin light circuit to wire in a relay?

Thanks all

Andy

[Clunk]

I believe its the fuel pump mate. Mine does the same but its within a few seconds of switching off the ignition. Some days more noticeable than others

[Parksy]

Thanks clunk, I have noticed it's more noticeable some days than others. Might have to have a close listen straight after shutting down. Any reason for it? Remove the pressure from the fuel lines maybe?

[Parksy]

Pink black wire running under drivers side kick panel is negative trigger. Figured it out.

[Clunk]

Thanks clunk, I have noticed it's more noticeable some days than others. Might have to have a close listen straight after shutting down. Any reason for it? Remove the pressure from the fuel lines maybe?

to be honest mate, I havent got a clue....... Anyone?????