Headlight Flash EV Mod

[kdmorse]

I remember the post in which someone detailed how to move the pin that controls the headlight flasher into the hole that controls EV mode for a quick and easy EV mod. (My OEM button is on order, but it may be a *long* time before I see it).

But now I can't find the post, and the forum search and I are not getting along again. Could someone who remembers which thread it was in point me in the right direction? I'd like to see if I can do it while waiting for my OEM button...

-Ken

[efusco]

Originally posted by kdmorse@Feb 3 2006, 02:51 PM
I remember the post in which someone detailed how to move the pin that controls the headlight flasher into the hole that controls EV mode for a quick and easy EV mod.  (My OEM button is on order, but it may be a *long* time before I see it).

But now I can't find the post, and the forum search and I are not getting along again.  Could someone who remembers which thread it was in point me in the right direction?  I'd like to see if I can do it while waiting for my OEM button...

-Ken

[snapback]203320[/snapback]

http://priuschat.com/forums/kb.php?mode=article&k=5

It's toward the bottom of the article. You DO still have to run a wire for this mod.

[kdmorse]

Ah - thanks - that's what I was looking for.

Would it perhaps be safe to clamp-splice the new wire to the existing purple wire in the steering wheel, instead of unpluggin the existing purple wire and replaceing it?

Or would I have to put a few diods in to prevent any backflow, which would completely negate the idea?

-Ken

[efusco]

Originally posted by kdmorse@Feb 3 2006, 04:36 PM
Ah - thanks - that's what I was looking for. 

Would it perhaps be safe to clamp-splice the new wire to the existing purple wire in the steering wheel, instead of unpluggin the existing purple wire and replaceing it?

Or would I have to put a few diods in to prevent any backflow, which would completely negate the idea?

-Ken

[snapback]203365[/snapback]

Not sure, maybe some of the electonic gurus have a comment on that.

[kdmorse]

Success! I can now toggle in and out of EV mode on my new 2006 (4 days old) simply by pulling the headlight stalk (That's just so cool). It took about 4 hours, and got a bit tricky when the sun went down on me. But having done it once I could probably do it again in under an hour.

(I did it as documented, didn't try to splice the to together)

Major hangups included all steps relating to fighting the white flasher plug (I only got the hang of it when I was all done), and fishing behind the head with real fish tape, which I stupidly got caught on a bundle of cables behind the nav unit, out of reach. It turns out inserting the pin into the ECU plug far enough was quite easy, and the least of my problems.

A few comments on your instructions, including a couple of tips that would have saved me some time.

>>To remove the pins, you can use your paper clip to start the process of sliding them out, and then they just pull right out.

It's worth pointing out that in order to release the pins, you must press down the little metal tab, *exactly* as is being done in the photograph. Not realizing this at first, I fought for an hour trying to remove the two pins by applying pressure elsewhere.

>>You may also need to unclip the little hydraulic piston that keeps the door from falling open too quickly.

I think this really needs to be done *before* pushing in the sides of the glove compartment to release it. Otherwise, no longer attached, the glove compartment can pull the piston off it's inside connection and possibly break it if too much pressure is applied to the glovebox.

>> Next, grasp the bottom of the silver vent piece next to the glove box.

Fought that vent for over an hour. No practical advice to add, just cursing the vent.

>> You'll eventually need to remove the driver's side (far left) vent piece as well.

Never did get that off, never managed to get behind it from any angle to release the clips.

>> Finally, remove the smaller square plastic piece just below the passenger side vent--it pulls straight out.

This plastic piece does not appear to exist in the 2006 model. There's a gaping hole in it's place.

>> You'll now solder your wire to one of the connectors

I made the mistake of using 24 gauge solid wire for this, and when I was angling to insert it into the ECU plug, the copper broke on me. Stranded wire worked much, much better on the second round.

>> Pull out the purple wire from the flasher plug and insert your EV wire into the now open slot.

Properly removing the purple wire will require splitting the two rows of pins into their two separate connectors (which are snapped together in a stack). A thin sharp knife between the two pops them apart quite easily, making it possible to release the purple wire properly but pressing on the same spot you use to release the spare pins. Just yanking it out otherwise is not a good idea. It also makes it easy to ensure your replacement is inserted properly, as you can see the pins end-to-end.

If the car starts buzzing after re-inserting the flasher plug (as mine did) - it's probably because the door is open.

Many thanks for putting these instructions together, there's absolutely no way I could have even come close without all the little pictures guiding me. (And they gave me a warm and fuzzy feeling that yes, I was tearing the right part off my 4 day old car). Everything went back together with no rattles, no left over parts, and no external evidence of any modification.

Thanks, Thanks, and more Thanks!

-Ken

[efusco]

Glad it worked out.

[letsail]

Just joined today; as I'm looking to wire the EV switch on my '04 Prius. I'm leaning toward using the headlight flash; I've found the full explaination of adding a momentary switch; but I like the idea of having the change "invisible" as my dealer changes my oil regularly.... and not needing a ground. Is anyone aware of a set of photos and/or detail for the unique part of the installation?

[kdmorse]

I didn't take any photo's, but there's really very little to it beyond the excellent directions posted for the momentary switch. There's already a picture of everywhere you need to go.

Make sure you're completely comfortable with all the steps involved before starting - ripping your car apart is a hell of a thing to do

Don't reassemble the steering cover after takeing a few pins out of it, you're not done with it.

Instead of running your new cable all the way to the left side of the car (where the switch would go), stop once you get to the steering column. This should be fairly easy, as when I ran it, it passed though the steering column on the way anyway, and I just reached in and grabbed it (after I had recovered from my fish-tape accident).

The plug that you stole the pins from, is really two identical pieces of molded plastic snapped together. One for the top (mostly spare) pins, and one for the bottom (mostly used) set of pins. You need to snap these two apart to get to the bottom set, containing the purple wire.

Note carefully which hole contains the purple wire. There is at least one unused hole, two wires over, don't loose track of which hole the purple wire came out of.

Remove the purple wire and pin, just as you removed the spare pins. (if you depress the metal catch with a paperclip, it should slide right out with little force - don't just tug harder).

Insert your wire and pin in it's place.

Snap the two plastic rows of pins back together, make sure you put the right one on top. When you're done you should see the mostly empty set of pins, and your new wire should be in the bottom, now inaccessible set of pins.

I personally chose to test it before reassembling the steering cover, vents, glove box, etc... When it worked, I reassembled the car.

-Ken

[pfile]

Originally posted by letsail@Feb 9 2006, 09:21 PM
Just joined today; as I'm looking to wire the EV switch on my '04 Prius. I'm leaning toward using the headlight flash; I've found the full explaination of adding a momentary switch; but I like the idea of having the change "invisible" as my dealer changes my oil regularly.... and not needing a ground.  Is anyone aware of a set of photos and/or detail for the unique part of the installation?

[snapback]206903[/snapback]

i did this mod a few weeks ago. my only advice is that when you are disassembling the "stack" connector from the steering column, be very careful. the plastic is very brittle and i managed to break one of the tabs that holds the stack together.

also bear in mind that the lights-on headlight flasher switch is still connected after this mod, so at night you will be flashing headlights all over the place when you are entering and exiting EV mode. i've become kind of gunshy about EV mode at night since i dont want people thinking i'm pissed at them.

also, generally speaking its easy to hose your gas mileage playing with EV mode. i usually only engage it if the battery meter shows green (7+ bars) and disengage when there are 5 bars left.

finally, i wonder if the "real" reason the EV button doesnt exist in north america has to do with the 10-year warrantee period on the hybrid drivetrain. having had the car for a couple of months now, i've come to realize that the drivetrain computer's #1 priority is maintaining a sane SOC for the traction battery. i've never seen the battery get down below 3 bars without EV mode, but the first day i had EV mode going i managed to get the battery way down into the purple zone... i know there's still lots of charge left even when the battery display is empty, but i guess what i'm saying is that the SOC excursion seems to be much greater when you are using EV mode, and i wonder if this has any effect on the battery's longevity.

[letsail]

Excellent thoughts; I really appreciate the advise.