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940 Fuel pump wire location?

Sjeng

Member
Joined
Sep 3, 2017
Hello tbricks,

I am looking for the +12V wire which goes to the fuel pump.
Any idea which wire this is/where to find it?

Reason I ask is because I am converting to MS and this is the last bit of wiring I need to sort.

Kind regards
 
Using a 1994 schematic, there were two EFIs...Bosch...Regina.

Are you wanting to power up the fuel pump(s) directly, or via existing relay? Eyeballing LH 2.4 MFI ECU, pin 21 (R wire) appears to activate relay....it would use a ground on this wire to activate relay. P colored wire at relay is direct to fuel pumps

For Regina, it uses a ground from ECU to power up relay...if needed, I'll fetch pin and wire color
 
Footnote - It may be possible to use your MS hot wire to power up relay, and just permanently ground relay. This way, there would be no real load on MS's +12V wire. I'll post schematic if interested.
 
Sjeng, do you have the wiring diagrams for your vehicle? I believe I have a full PDF for the 95 model..... as close as I could get you. PM if you want the file.
 
Pg. 60 shows the fuel pump, component 6/33, connected to fuse 11/11, from relay 2/23, using a pink wire.

Battery>>>11/1>>>Relay>>>11/11>>>P wire

Around battery area, you could catch 11/1 and hook MS's wire here, then pull out relay, and insert a jumper wire from 11/1's terminal to 11/11's terminal in relay's sockets.
 
Thank you all for the replies!

I will probably use the pink wire from 11/11, want to power the pump directly using my new relays.

I have thought about using the stock volvo relay and let MS ground it (using the wire coming from the LH2.4 ecu), but apparently the relay has a high current draw and MS might not like it.
 
I have thought about using the stock volvo relay..

I'm clueless how your MS wires are routed, and where your MS box will be located. Are you splicing into existing Bosch LH wiring, or doing a complete new setup?

Two Choices:

1. In engine compartment
2. Inside vehicle.

There are different ways to do it....and if you can use a ground or a 12v source, then more options.

You may be the last owner of this vehicle, but myself, I would attempt to kept wiring setup similar to OEM, when possible.
 
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