2006 TD4TI glow plug timer / module problem?

[Training Wheels]

So I bought a factory 2006 TD42 GU patrol a month ago and have had problems since..

Car started making a weird noise from the engine after about a week of driving it.. (rattly)

The dash started playing up.. glow plug light and check engine light would dim in and out instead of having a solid light when I’d flick the key and go out after about 5secs or so. Now the glow plug light glows in and out and never goes out and when I start the engine it sounds very rattly. Also there was a loud ticking noise coming from the wire connected to the injector pump so I suspected it needed a new wire or something. Anyway with that all going on I started the car and the lights would stay dimming in and out and the rev gauge wasn’t working and the car sounded like ass ( very rattly)

So got a auto elec around.. nothing. Took it to a mechanic and they timed it and gave it a service.. no fix, still screwed. Took it back and got the injection pump replaced and modified to a mechanical pump (no more wire) and got new injectors. Now the ticking noise came from the relay which I think is meant to happen but it never turns off. When I went to start the car the check and glow light would still dim in and out. Anyway started the car (thought it sounded better, it didn’t) drove it back to my place and on the drive it would go from operating properly (lights went out, car sounded right) back to no rev gauge and the glow and check engine light dimming in and out never Turing off (car sounded like shit when this happened) (while driving it was going from good to bad to good to bad)

Got the glow plug relay replaced today and the car still wouldn’t start.. I’m no expert or anything so can’t exactly explain what’s going on with the glow plugs and timer but the mechanic said it’s most likely the glow plug timer causing the issue, so they added a button to press to activate the plugs manually before starting the car.. which I’ve been told has got the car running again (not sure if the rattling is gone haven’t got it back yet) but the dash is still having the same issue which an auto elec has told the mechanic that it’s PROBABLY all running through the glow plug timer (which cost $1500 new apparently) so for now I got the button until I find a 2nd hand one for cheaper.

(I’m sure I’ve got a lot of this backwards and missed a few things)

Now.. suspecting the rattlings gone and the dash is the only issue, I’m curious if the dash does run through that module? and if putting the button in should have fixed the dash also? Or if there’s a better way to add the button temporarily whilst also having the rev gauge, check engine and glow light operate correctly? Or do I just need to fork out the money and pray it fixes my issue?
(Not sure what they’ve done to add the button in, will ask when I pick her up this arv and update)

Also anyone have an idea why the car sounds like ass when the dash does play up? (Will update if the noise has been fixed by what should now be working flow plugs)