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WebElectric DRL-2P installation into 2012 Prius v

Discussion in 'Prius v Accessories and Modifications' started by Offline, Jun 8, 2013.

  1. Ivan White

    Ivan White Junior Member

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    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    I have now used an add-a-fuse to fuse port 29 for both 12V power and the black wire. Since it appears to be a fused ignition-inverter-converter port, will power not be cut off when I power down? No need for a relay? Also seems to have fixed the on-off problem by adding the black wire. Thanks xliderslider!
     
  2. xliderider

    xliderider Senior Member

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    Model:
    Three
    The DRL module has automatic current sensing. It senses the difference of the car's 12v system when in standby supplied only by the auxiliary battery, and the 14.x volts when the system has the high voltage traction battery online (Ready mode).

    I'm just anal, the seller said the standy, or parasitic draw of the DRL module is very low, in the millivolt range. However, the Prius battery is quite small, so I put the relay on it.

    The relay is your plain old Bosch type 4 or 5 terminal automotive relay. It is wired between the positive wire from the fuse box and the DRL module. The signal wire is tapped off the ignition switched seat heater circuit mentioned in my previous post. You can use any circuit that is powered only when in Ready mode, the relay coil takes very low current to energize the coil.

    If your setup is working fine, don't put the relay in. I may be shortening the life of the DRL module by turning it on and off repeatedly instead of leaving it on to work automatically as designed. Kind of like the turning the computer off or leaving it on, which is better, debate I guess.
     
  3. xliderider

    xliderider Senior Member

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    I'm not sure that you should be getting the power from the circuit you are using (fuse 29) with the red DRL wire. The black wire is OK, because it is a low current draw. The red wire on the other hand is the main power wire and it has to draw enough power to light both highbeam bulbs at approximately 20ish watts, it's under 2 amps, but still, the way you are tapping off a fused circuit, the load is in addition to what's already on that circuit. That's why the instructions say to connect the red wire to the battery.

    It would be much better to draw power off one of the open terminals in the fuse box, like in my picture in the previous post. The deluxe DRL module has it's own fuse, so that circuit is protected.

    Just use the tapped fuse 29 for the black wire, or if you use a relay to control power on the red wire, you can also use the fuse 29 tap to supply power to the relay coil terminal since it is also low current and there will be no danger of overloading that circuit.
     
  4. Ivan White

    Ivan White Junior Member

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    Xliderider, great advice! Thank you. I think I'll go the relay route, but need some additional info. as it's been a while since I wired in a relay. I have a 12V 40A 4 prong relay with 85/86/87/30 poles. If I understand you correctly, I cut the red wire and wire it into 2 of those poles and add the black wire into a 3rd. Would you please tell me which terminals to use? Thanks again for all your help
     
  5. xliderider

    xliderider Senior Member

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    Here's a diagram I found for a 4 terminal relay:

    [​IMG]

    Terminal 30 is the one you connect to the fuse box (battery).

    Terminal 87 is wired to the DRL side of the red power wire.

    Terminal 85 is grounded.

    Terminal 86 is wired, in your case to the tap off fuse 29 (switched ignition circuit) along with the black wire from the DRL module. This will supply a switched power control signal to both the relay, which controls power to the DRL module, and provides a manual On signal to the DRL module (overriding the current sensing circuit).

    Assuming your relay is type NO, or normally open, where energizing the relay coil causes the circuit to close.
     
  6. Ivan White

    Ivan White Junior Member

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    Thanks again. Exactly what I needed.

    I may just hot wire into an open terminal in the fuse box like you did, rather than run another ground wire for the relay. In my car, the terminal where your red wire with red connector is located has a 30 A box fuse in it. Just below it, and where your red wire with white connector is located in your photo above, the space is empty with a large single blade inside. Is this where I might pick up 12V power? The fuse box cover diagram does not indicate this is active.

    I really appreciate all your help on this. I initially used the #28 and #29 fuse location, as that's where the Webb DRL installer at the beginning of this post suggested. I FORGOT that he was using LED turn signal lamps for his DRL's that presumably use much less amperage , so he was probably safe in doing so. Thanks for pointing out the 2 amp load from the 30% high beams on this fused ignition circuit! A relay is the way to go if I use that fuse for 12V power!
     
  7. xliderider

    xliderider Senior Member

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    Yes, single blade connection, use any 1/4 inch crimp on connector with insulation or use heat shrink tubing to insulate. The terminals are always hot, so they're OK to use with a relay.

    SCH-I535
     
  8. Ivan White

    Ivan White Junior Member

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    Wired in the red wire to the single blade hot terminal and black wire to Fuse 29. Works perfectly now and no risk of overloading the ignition circuit. Decided against the relay to avoid more wires, as the phantom voltage to the module should be quite small. Xliderider, where did you mount the module? I now have mine velcrowed against the front of the fuse box. Seems stable enough and the wires are tight enough that it won't fall far if it come loose. Thanks again for all your kind help.
     
  9. xliderider

    xliderider Senior Member

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    I have my DRL module, along with the relay and all the extra lengths of wiring (didn't want to cut any wires, in case I move it to another vehicle later), enclosed in a plastic project box and mounted in the space in front of the driver's side wheel well, below the headlight. I fashioned some brackets out of steel angle braces and mounted the project box from some available mounting points.

    Glad to hear everything is working well in your installation. (y)