12+ volt ACC wire

If / when I do, I'll post some pictures.

 

Dang Chapmanf!! That's a very elegant solution to potential battery problems. Went online and ordered a VCM-06 from Waytek. Thanks!

 

Happy to help! I'll be interested in what you do with it.

-Chap

 

Well, it wasn't as elegant as I'd anticipated. In fact, it was a pain. The firewall penetration is on the passengers side, behind the glove-box. With the glove box removed, you can see the penetration behind an electrical junction point (it's to the right of the cabin air-filter housing).

I was assuming that the plastic tray the surrounds the windshield wiper assy. was removable (like the one on my 2005) but I found that it might not be, so I didn't go any further. This was going to be the means of accessing the firewall penetration (it was the routing that I finally did take, but there were more deleted expletives than I care to mention). It would have been a much easier job were I 30 years younger.

The project that took me to this endeavor was a new Kenwood TM-V71A dual-band transceiver (ham radio stuff). I learned a heck of a lot about disassembling / re-assembling the various components of the new Prius. Not sure I'd go through it again. I did take pictures, but I'm not sure if they're worth trying to post. I also installed one of the InPower low voltage disconnects suggested by ChampanF. Good suggestion, and a clean install.

Now, I'll check the SWR for the VHF and UHF bands on the new radio, and see if I can hit any of the local repeaters.

 

Please do post some pics!

73 de S56OA - Ogo

 

OK, but it's going to be a chore. Not real familiar with the process, but I'll do my best.

The "very first thing" to do, is to remove the negative battery terminal, and isolate it so that it doesn't touch the post while your working on the car. Rubber / cardboard or another insulating material works just fine.

 

Next, remove the glove box. This is very similar to the older generation Prius models. Un-hook the return spring lever on the Right side; pull the upper left side of the glove box to the right; the box swings down and pulls out. From the floor, you can see the cabin air-filter housing. Very easy to open the tray, and install a new air filter yourself when needed.

 

I mounted the control head of the radio to the bottom of the shift lever housing. All wiring between the radio (which is located under the front passengers seat) to the control head is routed through the plastic side moldings along the floor and the kick areas. These pull off for the most part, but there is a plastic push-nut on the kick panel, which unscrews by hand.

 

To remove the trim at the shift lever console, first unscrew the shift knob. Then "gently" pull the trim ring out (be careful, as you can actually pull the black "trim cover" off, rather than the trim itself).

 

Bad Toyota!!!! The buttons are still attached to the trim ring: the "park" button on the left, and the "drive mode" "EV mode" buttons on the right. The problem is that there wasn't a lot of slack wire to the back of the buttons, so you can't pull the trim out far enough to "easily" remove the buttons. But, the buttons can be pried out of the retainers easily. Start on the passengers side (the dual buttons). Once these buttons are free, then transfer to the drivers side, and gently pry the single button out.

 

This is a picture of the console, with the trim ring removed. I don't have anything further picture wise. In order to remove the actual housing around the shift lever, it became necessary to remove the kick panel from the drivers side foot compartment; and the bottom cover under the steering wheel. This allowed me enough room to pull the left side of the shift lever housing out, and remove the housing completely in order to attach the radio control head.

 

This is a picture of the final 12V connection at the battery. Both the positive (+) and negative (-) conductors are fused. I also purchased a VCM-06 low voltage power disconnect, and installed it in the circuit. The VCM-06 is a very useful and, in my opinion, necessary protective device to any "after market" electrical installations on the Prius. Many thanks to ChapmanF for bringing this device to my attention.

 

One thing about the VCM-06, I'm not sure it's perfectly sealed; there's that little hole for the time-delay adjust. If I were putting one in the engine compartment, I might put a little blob of something over that hole.

Another thing that surprised me about it was that I measured something like a 7 mA (IIRC) draw from it when off. I emailed InPower and the response was something like, yeah, that's about right, powers the microcontroller inside. And I thought, huh? wouldn't you just design it to be OFF when it's off? You could use a simple trigger circuit to wake it up when the voltage rises; shouldn't need the microcontroller except while it's ON....

 

you have a good point, VCM-06 even if it drew little power would be devastating to the prius lead acid battery. Parking for months only to find out the prius battery is dead and costs $100s of dollars down the road. Solution should have been simpler where tapping into 12v cigarette lighter port. Im also looking for 12 switch acc power line on the trunk for tilt alarm. Can seem to find it. I dont want run across


thi

 

There's still one in my Gen 3. I just make sure to drive the car a little every week or two (even under COVID-19 measures); that wards off many kinds of damage.

The 7mA quiescent draw doesn't end up being a problem on that timescale.

 

Yeah I measured something like 16~18 milliamp's background draw, with momentary spikes to a bit over 40 (maybe every 5 seconds, didn't seem to coincide with the little security icon blinking on dash, but seems a likely suspect). Anyway, an additional 7 would be a healthy 1/3 increase, over that steady draw.