04 prius --- dead !

I'm a newbie to posting here, but have been reading for several months, when I bought my first 02 Prius last fall. It was wrecked, but I rebuilt it and it's been running fine since. I put in one of the Miata replacement battery kit's, and the 02 has not had any problems at all. (just drove it on 800 mile trip)

Also bought a 2004 Prius recently (loaded Touring, 56,000 miles, smart key, etc.), and it was wrecked in the front. I put it back together, replacing bumper, hood, radiator, inverter reservoir, fender, etc....anyway it started up fine, and I drove for about a week. Started with no problems.

It seemed like the gas mileage was lower than it should be for the 50-100 miles or so I drove it, after first getting it running, after the accident repairs. (also making me wonder if the 12V battery was weak)

Then all of sudden the doors wouldn't lock with door handle push button, or keyfob. I drove it again a couple of days, and it ran OK.
Then when parking it last week, I shut it off...but needed to restart it to back it up a few feet, then....nothing...no dash lights or ready light, and car won't turn over or start...it's dead !

So, I figured the 12V battery was bad, and since I was going to keep the 04, I replaced the 12V, with the Optima replacement battery.
...but it made no difference...car is still dead...no dash lights.. except for red security light, and the slashed white key light, that seems to show no smart key?....I don't hear water pump running either.

The outside head lights, tail lights, interior lights all work. ......But no radio, display screen, etc (the drivers window is rolled down, and can't get it to work) but the doors will lock with manual door switch.

I also checked the small button setting to shut off the smart key system, but it is the on position. I also tried putting the smart key in the dash slot, and made it made no difference...it's still dead.

The smart key blinks when pushing the key fob buttons, but won't lock doors, or unlock them...the emergency red key fob button does nothing either.

So, what next !

 

Thanks for the comeback Patrick. I already did the fuse checking, and did find the horn 10amp fuse blown.

But I did go back through the 12V batt system, checking all connections, and retightening everything I could find. I also put a batt charger on the fuse panel jump starting post to run a charge through the systems from the front.

Presto change-o...it now starts and runs....so somewhere there was a poor connection...not sure where.

But after getting it running...and already replacing the 12V batt, with the Optima battery....it definitely runs a bit better, and I can see the gas mileage improvement go up, more easily than before. (Also changed the Key fob battery, but it made no difference, but it will work for a long time )

Anyway this is my second Prius rebuild and just bought a 2008 to rebuild. Needs a rear quarter panel, rear axle, and rear bumper. My son will get the 04 Prius when I get it completely done. Got a couple more small things to do.

Anyway working on the Prius's have been educational...learned a lot....very different from a "normal" car.