Hello chaps,
I have a small technical issue with removing a B200. The engine loom is seperate and easy to understand, but there are two wires going into the main vehicle loom that I can't find a purpose for. Here are some pics I took to illustrate the query:
They connect to this relay which is mounted to the little stell bracket which supports the airflow meter:
The reasons for this engine carry on will be made clear soon, but for now I'm off to sleep, to dream that people come to my aid and explain TEH WIR3Z to me.
So could I do without them entirely and have my fuel pump controlled by a switch? That's how I have it in my 340. The thinner of the two wires appears to be an ignition live, perhaps the other is an earth?
Sounds quite likely that the ignition would have a dedicated earth rather than just a grounded to the body/chassis - you my friend need a wiring diagram:
Hiding as I can't remember LE jet wiring this morning...
From the greenbook in Ronnie's link, that relay is I on P10 (11 of the PDF), referred to as J12 elsewhere. It's called the control relay, and it provides power for the LE ECU, fuel pump and lambda if the car is fitted (which as yours is a UK car, it won't be).
I can't see what colour the car wires are (they look both blue... but thats a bit special...) however on the LE jet loom they are brown and white/grey? I am wondering if the 2 blue wires car side are non Volvo, brown is always ground in a 300, and Volvo always put brown to brown as far as I'm aware.
The LE jet loom should just pull away, and you never have to touch any of those wires again if you don't want to. I've a guess as to what you are doing though, and in which case there should be provision to run the fuel pump off of that loom, again, entirely separate to the LE jet one. If you do the job properly you'll be able to add the new loom in one piece like the LE jet one, and keep everything separate.
Cheers Chris, you might have jumped the gun a bit but you're on the right track regarding what's going in this silver car next. I'm fitting the B200 to my ex-valvo, mainly for the stronger drivetrain and because I'd like the blue one to be a T5 LPG daily eventually. So basically I need to know where these two wires terminate so I can replicate them in the 340. I know your feelings on redblocks but I just want something bulletproof for the winter.
The blue wire is a switched live, switches on and off with the ignition. The white wire is a coax cable carrying the RPM signal from the Renix. That relay is more than just the fuel pump. It works the entire LE-Jet system, powering the injectors, ECU, TPS etc as well as the fuel pump.
All the 700/900 stuff, Motronic, LH2.4 etc etc use a different system, where the ECU is energized by the ignition and then the ECU decides when the fuel pump should run, more the traditional way of doing it rather than this rather strange way of controlling it. Its the reason you won't hear a fuel pump priming when you turn on a 360 until you try to start it up.
Thanks Andy. Been messing with a multimeter, and both wires change voltage with the ignition. The blue behaves exactly like you'd expect an ignition live to, with 12 volts. But the other appears to give 9v with the ignition on, and both appear to give a tiny trickle of current whether the key is turned or not.
The latest idea is to transfer over the whole engine bay wiring snake from the GLT to the 340, can anyone foresee a problem with this?
They look almost exactly the same, the only extra electricals on the GLT are leccy windows and fogs. And this wire disappearing into the car is for the fuel pump:
