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Old 12 June 2018, 04:23 PM
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bengo
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Default Twin Bosch 044 Wiring

I'm currently in the process of fitting twin Bosch 044s and a swirlpot to the back of my Bugeye.

I've added 2 fused wires from the battery to 2 relays in the back and have grounded the relays and pumps to n earth point in the boot. What do people usually do to trigger the pumps? I was hoping to be able to splice in to the fuel pump connector at the top of the fuel tank but I'm not sure which wires I use, does any body have any advice please?

Thanks
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Old 12 June 2018, 07:29 PM
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trevsjwood
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on my Blobeye wagon I have the relay wired to the fuelpump controller which is in the offside rear wing, access through boot inner panel. I would think there's a fair chance it's the same on the bugeye saloon.
I cant be certain now as it's a while since doing it but you should have 6 wires running to controller. I think it's the two large black/white wires you want and relay 85 is wired to 2nd one in and relay 86 is connected to the outside b/w of the 6.
That way the 044's act the same way as your fuel pump, prime and stop on ignition etc.
Sorry can't be certain as I don't seem to have the definitive record of what I did anymore but that's where you want be.
Trev

Last edited by trevsjwood; 14 June 2018 at 10:17 AM. Reason: typo correction
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Old 13 June 2018, 10:16 AM
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bengo
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Hi Trev,

Thanks for the info, unfortunately I'm even more confused now lol!

I was hoping to just splice into one of the wires connecting to the intank pump and use that as the trigger, but if the controller is in the boot it seems like a better place to tap into.

Are you saying:

* pin 30 - goes to the battery (fused)
* pin 87 - goes to the positive on the pumps
* pin 85 - goes to 2nd from outside wire on controller
* pin 86 - Outside b/w wire on controller

I take it i'm splicing into the original fuel control wires too (as I need to original pump to work as normal for the lift pump)?

Thanks, should be easy I'm sure, but I'm crap with auto-electrics!!

Cheers

Ben

Last edited by bengo; 13 June 2018 at 10:25 AM.
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Old 13 June 2018, 11:23 AM
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trevsjwood
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hello Ben,
I don't know auto electrics much at all but got info mainly from NASIOC when I installed a few years back.
Yes agree with those relay pin settings.
No you don't splice into fuel pump wires elsewhere if that's what you meant?
Re- connections, just to confirm, with the FP controller face up- pin 85 to wire 2nd in from left, pin 86 to wire outside right. However, because I'm not dead certain I would test it before taping up i.e. that it primes on ignition switch and then shuts off as with car fuelpump. The only other alternative is 86 to outside left, 85 to 2nd from right and that's where I'm not sure.
I have it 86 is a live, 85 is a switched earth.
Trev

Last edited by trevsjwood; 13 June 2018 at 11:49 AM. Reason: add info
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Old 13 June 2018, 12:34 PM
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Thanks Trev, that's really useful.

Have you had any problems running your pumps off the controller with the relays? I only ask as apparently the fuel pump controller is PWM (for controlling the speed of the intank pump), but the relays won't work with PWM meaning that the external pumps wiil be constantly at 100%?

Regarding the splicing, what I was trying to say, when i cut into the wires at the controller for the relays, I take it I need to resolder the original wires back in place after adding the new wires in?

Once i've got this sorted I'll post a wiring diagram and some photos as finding info has been really difficult!

Cheers

Ben

Last edited by bengo; 13 June 2018 at 12:37 PM.
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Old 13 June 2018, 03:28 PM
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re- splicing. yes keep the original wires as they were.
Yes the external pumps run 100% whilst the engine is running, required fuel pressure is met and excess fuel just feeds back to the tank. All you get from the controller is basically an on/off but it happens insyncro with car pump. I did find my fuel pressure went up 0.3 bar at idle so I tweaked back to normal pressure, that's just with a single pump. I run an adjustable FPR (fuelab) with gauge and a Stack in car gauge. No issues other than the raised FP.
Trev
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