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Wire Route through bulkhead / firewall

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Old Oct 4, 2008 | 06:26 AM
  #1  
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Default Wire Route through bulkhead / firewall

Hello, can anyone help me?

I have a UK RX300 2004 model (roughly the same as US rx320).

I am running a 12v supply to an aux towbar connector from the battery to the towbar connector.
Can anyone suggest the best route through the firewall to the battery - i've removed the glovebox and see that there are 2 grommets with looms going through - but these appear to be too tight to thread a wire through.

Alternatively is there anywhere else i can pick up +ve for the supply?

Cheers all
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Old Oct 4, 2008 | 10:08 AM
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Based on 99RX [for USA market ... left hand drive], the main fuse box in the engine is engine is on the driver side and the distribution fuse box is by the driver left knee. The wire bundle runs in through the driver side wheel well ... tucked behind the plastic liners. The wires enter the cabin through a rubber grommet ... way up in the corner ... couple of inches below the windshield. The nice thing is that the entry point does not compromise the fire-wall.

I routed an accessory wire through it ... and it was hard as the original harness was made to match the hole in the rubber grommet.

You can always pick switched 12v from the cigarette lighter.

Salim
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Old Oct 5, 2008 | 01:10 AM
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Originally Posted by robbiemcve
Hello, can anyone help me?

I have a UK RX300 2004 model (roughly the same as US rx320).

I am running a 12v supply to an aux towbar connector from the battery to the towbar connector.
Can anyone suggest the best route through the firewall to the battery - i've removed the glovebox and see that there are 2 grommets with looms going through - but these appear to be too tight to thread a wire through.

Alternatively is there anywhere else i can pick up +ve for the supply?

Cheers all
Best not to run power wires like that next to critical electronics wiring loom anyway. You can get electrical interference through the insulation. That's how you are able to read the draw with an amp clamp. I did code3 outfitting and we had to be conscious of where we were running power wires so that they didn't produce interference with radio and other critical electronic gear. The insulation on wiring may protect you from shock but not from interference with electronics at close range. The PCM (power control module- computer) loom runs through 1 of those grommets on the R side behind the glove box.
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Old Oct 7, 2008 | 01:26 PM
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Default Transceiver power lead direct from battery thru firewall?

Originally Posted by code58
Best not to run power wires like that next to critical electronics wiring loom anyway. You can get electrical interference through the insulation. That's how you are able to read the draw with an amp clamp. I did code3 outfitting and we had to be conscious of where we were running power wires so that they didn't produce interference with radio and other critical electronic gear. The insulation on wiring may protect you from shock but not from interference with electronics at close range. The PCM (power control module- computer) loom runs through 1 of those grommets on the R side behind the glove box.
Hi Code58:

I need to run a DC power lead direct from the battery for a 50 watt VHF ham radio transceiver, drawing 20 amps. If I ran it through this grommet, would you expect interference? I would not expect RF to feed back thru the power lead, but nor would I want the power lead to pick up electrical system noise to interfere with the radio operation. Any comments appreciated; please forgive if my ack/response is late -- am travelling overseas with poor connectivity. Thanks.

Last edited by tawm; Oct 7, 2008 at 01:27 PM. Reason: mis-speling
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Old Oct 7, 2008 | 03:03 PM
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You may have physical limitations, before you run into electrical interference.
Lots of electrical interference can be eliminated by caps and filters in the dc supply.

Salim
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Old Oct 8, 2008 | 07:03 AM
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thanks for the replies - where would you suggest - drill another hole?
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Old Oct 8, 2008 | 10:47 AM
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That is where the problem is. If you drill a hole, you will compromise the firewall. If you do, make sure you use a rubber grommet to protect the wire and some how seal the opening.

Salim
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