Thread: Wiring power sources.

Do not run the pump from the cig lighter. It won't handle the job. But you could power the pump via a suitable relay and run the switching wire from the cig lighter or the accessories wire at the key. But remember to fuse appropriately. If you don't use a switch though the pump will run all the time the ignition or accessories are on.

Hello Landy,

I have Goss solid state universal fuel pumps. They draw 1 amp at full flow. Most cigarette lighters would be fused to about 30A, so I thought it would be a fine place to start.


Cheers,

Phill.

Originally Posted by Longtimer

Hello Landy,

I have Goss solid state universal fuel pumps. They draw 1 amp at full flow. Most cigarette lighters would be fused to about 30A, so I thought it would be a fine place to start.


Cheers,

Phill.

they are fused at 10 amps.

for your application pul the aux + for the trailer socket inside the real light cluster and use that, drive it to the feed and source voltage for a pair of relays, use the delivery for the relay to drive the pump and then earth switch the relays.

IF your Aux+ is live all the time there should be a brake feed+ that comes on with the ignition. failing that pick up the fuel pump feed.
faiing that run an AUX power outlet and tap the back of that.

b

Originally Posted by Longtimer

G'Day All,

I have finally gotten around to fitting my belly tanks to my 90. The only thing left to do is fit the OEM style switches into the dash, and run the wires.

So here's my questions, but please understand that I have not yet tried to remove the dash, so I have no idea on what is behind there.....

Where is the best place to take the pump power from? I am assuming the smoke lighter?

Just as an aside..... Has anyone else noticed that if you let the smoke out of the wires they don't work???

Is it best to try to come from the fusebox? Or is the back of the lighter ok?

Where is the best place to run the dash light wire from?

On the way out of the dash..... Which is the best way out, to run down to the pumps? Don't forget that there is one either side in front of the rear wheel...

And the earth..... Is there a good place to join a common earth?


Thanks for all recommendations. :-)


Cheers,

Phill.


PS.... My BAS remap has changed the way car performs. It's amazing!!!!! Don't just think about it, get one.

Phil,
I recently did almost the same thing you are trying to do with my winch master on/off power: OEM dash switch controlling the power to the system. The challenge is that the switches can not handle the current that the main pumps and motors need; the switch would just melt. Instead the switches are powered by 12V accessory, and act as the gate-keeper allowing the heavier duty relays and solenoids to only turn on with the key in the ignition and you pushing the button. This saves you forgetting the pump is on when you get out of the car, and run the battery down.
I will describe it for you in case it can help.
-OEM dash switch sourced from Mulgo
- illumination power from cig light socket in dash
- 12 V accessory power (and fused) from factory fuse box below dash. I used an empty fuse holder to create the factory looking fuse and power for the switch. Wires run from switch behind dash and pop out to back of fuse box.
- The switch can't handle the power supply to the pump, so run the switch to a relay as 12V accessory signal to the relay.
-Relay in between OEM switch and main solenoid to send switch signal to solenoid.
- Power the relay from battery (via fuse) and 12V accessory signal from OEM switch. Then the relay directs 'ON' 12V power to the solenoid that controls powered 12V+ from power source (battery) to the fuel pump.

Summary, each point in the system (switch, relay, solenoid) have their own power supply, but each receive the 12V accessory signal from the component upstream from itself. This allows the switch to control the power to a motor that it would not be able to on its own. Having the switch powered from 12V ignition prevents the human from forgetting its on and running the battery down as well.

G'Day ThorneGator,

Thanks for the info'.

All help is valued.

OK, so I need to get a couple of relays. Where is the best place to mount them? In my Series Landies there was plenty of room under the bonnet. There doesn't seem to be much room in my Defender's engine bay.....

Isn't there a main junction that I can take the power for the relays from, rather than the battery? If not I will have to fit one, as I don't want a whole heap of wires comming into the battery box. It's hard enough to get the jack in and out now. And once I go to twin batteries, there won't be any room.
Now here's a thought.... I wonder what they did when they fitted my spotties at the dealership????? I remember seeing the wires going back under the car, but I didn't make the time to follow them through.....

What about the earth point for the switches? Isn't there a common earth point in the dash somewhere?
And what about the dash lights hook up? How did you do that?
I am assuming that there is only one grommet to run my wires through.

I am hoping to have some time Saturday to explore where I will put things and how to get there....

Cheers,

Phill.

Tried the drivers seat box - relays all the way to the bonnet area is inducing voltage drop and wasting effort...

Phill. Both my sill tank pumps are fed directly from the ciggy lighter power under the dash. Current is not an issue as the fuel pump switches have no problems with running the pumps through them. I have run both pumps simultaneously for an extended period of time and had my two-way on and had my phone plugged in to the ciggy lighter outlet and no problems with the 10A fuse of the ciggy circuit. Yes, using a pair of relays is always a good idea but really is belt and braces overkill for the joy of spending and over-complicating things.

Originally Posted by Longtimer

G'Day ThorneGator,

Thanks for the info'.

All help is valued.

OK, so I need to get a couple of relays. Where is the best place to mount them? In my Series Landies there was plenty of room under the bonnet. There doesn't seem to be much room in my Defender's engine bay.....

Isn't there a main junction that I can take the power for the relays from, rather than the battery? If not I will have to fit one, as I don't want a whole heap of wires comming into the battery box. It's hard enough to get the jack in and out now. And once I go to twin batteries, there won't be any room.
Now here's a thought.... I wonder what they did when they fitted my spotties at the dealership????? I remember seeing the wires going back under the car, but I didn't make the time to follow them through.....

What about the earth point for the switches? Isn't there a common earth point in the dash somewhere?
And what about the dash lights hook up? How did you do that?
I am assuming that there is only one grommet to run my wires through.

I am hoping to have some time Saturday to explore where I will put things and how to get there....

Cheers,

Phill.

Phill,
I would look for space for the relays with the fuse box above the gearbox tunnel, there might be space there. Otherwise, I mounted them inside the battery box, mounted on the wall of the box...still enough room for the batteries. Another option is an exbox from Mulgo, that will give you extra room for your electronics.

As mentioned earlier, I would try to keep the relays as close to the power source as possible. Additionally, to avoid the wiring mess you can run one main wire from power to a fuse box.
I will try to take some photos of mine to show the wiring path.