Dome light, key fob, clock, no radio, VSC

To all you people who do not drive their Prius much, buy a battery maintainer and use it every time the car is laid up.. 12 V battery problems will go away and your 12 V battery will last much longer.

Get a modern automatic with AGM detection (or switchable) that charges 4-5 Amps and has a quick attach pigtail that you can permanently connect to the 12 V battery terminals. You should find something that meets that criteria for less than $50.

 

The reason I gave a critera list is that I can't really recommend a particular product, as I'm not that familiar with what is available on the US market.

The only only one I can personally recommend is the CTEK MXS 5.0 which is what I use.

However, I have seen others recommend a Harbor Freight charger and also I have seen people recommended
CTEK MUS 4.3, Schumacher 1000A-CA and Schumacher 1500A-CA. I don't have an opinion on them but would be happy to try any of them.

Also, in addition to what I said previously:

Make sure that you do not get a trickle charger (or battery maintainer), but one that is a proper charger that will go into a maintenance cycle after charging. This way you get the best of both worlds.

I just re-read my OP and want to expand/clarify this part (as editing the post is now not possible):

I should have said: buy at least a battery maintainer, which is good for keeping a relatively fully charged battery full, but even better get a proper charger that goes into a maintenance cycle once the battery is fully charged, and use it every time the car is laid up.

The way it was written made it a bit contradictory to later advice. Sorry about that.

Hope that helps.

 

My 12V battery is new ! I think it may be a problem elsewhere!

 

Hi ! You've solved the problem ? is the car okay ?? thanks

 

I have this exact same issue.

 

DOME fuse? Just guessing, since I don't have my drawings available right now.........

 

ANYONE HAVE INPUT ON THIS>

I have replaced relays- all fuses underhood and in fuse area at drivers foot
I am beginning to wonder about Body ECU.....

 

I have the same exact problem. I Checked fuses. Put in new 12v battery. At first all the electrical issues would come and go. Now all the issues have been constant for about a month. Car drives fine but no Radio, interior lights, clock, smart key doesn't work, VSC light is on. I believe all of these things are on the same line. My fuse is good so I was thinking broken wire or bad connector. I see a few posts with these same symptoms but no answer to the problem. My car has like 310000 miles so it owes me nothing but I do miss the radio and having to unlock the door using the actual key. Any ideas are appreciated

 

Let's start with the clock. It receives power from three fuses: 7.5A PANEL, 7.5A ACC, and 15A DOME. Check all three fuses by removing each and measuring continuity with an ohmmeter.

Also, measure voltage from the fuse socket terminals to ground. You should be able to measure 12VDC from one of the terminals to ground, with the ACC fuse removed, while the car is IG-ON or READY. The DOME fuse should have 12VDC at the socket regardless of whether the car is IG-OFF, IG-ON or READY. The PANEL fuse should have 12VDC when the exterior lights are turned on.

 

The dome fuse solved my exact problem. 5 th one up in the fuse box on bottom left row under hood. 15 amp LP fuse.

SM-N950U1 ?

 

I checked those fuses for continuity with my ohmmeter and all were good but I will check them again along with the voltage you laid out. I appreciate your help and will report back what I find out. thanks

 

I did check this fuse but will check again. Thanks for your reply

 

So I checked the fuses that you recommended and all were good. I also checked the voltage for each one and they all come up with 12vdc. Any idea what my next step is? Do you know if there is some sort of junction box or ecu (like mentioned above) that could be a problem. Any help is appreciated. Thanks

 

I am in the exact same boat
fuses all good. 12v at fuses.
leads me to think a body control or a wire is cut.... as no door lights/dome lamp
smart key, radio , dash lamps around smart key

 

The next step is to measure voltages at the clock to see which wire is broken. Then run new wiring as necessary. Time to get the electrical wiring diagram at techinfo.toyota.com

 

Im pretty sure the wire that is causing the problems is the one that goes with the Dome fuse. there are people with my same symptoms who end up having a blown dome fuse. Wish I was that lucky. Im hoping I can figure out the wiring schematics. Thanks for your help