E48 relay wiring

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E48 relay wiring

Postby Jp69 » Sun Dec 23, 2018 4:16 pm

I have an old e48 ecu and loom that I have just fitted to a c20xe vauxhall engine. I'm a bit stuck on what wiring to use for both the ecu relay and fuel pump relay. I have wired everything up temporary and works perfect. What size wire should I use for the relay wiring? Switched +12v, permanent +12v etc. Any help would be much appreciated cheers
Jp69
 
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Re: E48 relay wiring

Postby stevieturbo » Sun Dec 23, 2018 5:40 pm

Size of wire will depend on the load of whatever device you are powering with the relay

The ecu triggers the relay via ground, not 12v.

The ecu itself would not draw much current, and fuel pumps vary.
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Re: E48 relay wiring

Postby Jp69 » Sun Dec 23, 2018 6:25 pm

Spoke to dta and was told that the ecu triggers the fuel pump relay via earth (pin 10 on ecu) which I have done and it works fine.
The ecu relay I have connected to pins 21,22,23,24 and 25 which I believe are for power to injectors, coilpack and ecu itself.
Both relays are 30a with a diode fitted, both 4 pin also. And are both connected to the battery vid 20a fuses.
It is running a standard vauxhall injection fuel pump if that makes a difference, but will be upgrading to a walbro 255 in the future
Jp69
 
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Re: E48 relay wiring

Postby katana » Mon Dec 24, 2018 6:28 am

Have a look at the S series manuals - they have guidance on wire spec's. page 105 in S60 manual.
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Re: E48 relay wiring

Postby Alex DTA » Tue Dec 25, 2018 5:26 pm

Pins 21 to 24 are signal outputs, they shouldn't be connected to a relay

Pins 21 and 22 (if used) go direct to the injectors.
Pins 23 and 24 go direct to the coil pack.
Pin 25 only should be connected to the ignition relay.
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Re: E48 relay wiring

Postby Jp69 » Wed Dec 26, 2018 2:50 pm

Hi Alex thanks for the reply. Without having the loom in front of me, I'm sure there was 2 thick red wires coming from what looked like pins 21-25 that broke off into a sub loom (round 2 pin connector) marked relays. I have connected both these to a 4 pin relay, along with a permanent earth, switched live and permanent live.
The fuel pump relay I've wired to the fuel pump, permanent live, switched live and the earth comes from pin 10 of the ecu.
The car starts and runs fine.
I think I'm going to use 17amp cabling for the wiring of the relays I.e switched live, permanent live (with a 20amp fuse) and also the earth.
Jp69
 
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