Me again ... I will be replacing this pump some time next week. I am reluctant to drive the car I don't want to do any damage to the transaxle. To prevent the 12v battery from discharging I plan to do one or both of this. 1- turn off the smart key and 2 disconnect the 12v battery. Will removing the positive lead at the jump point isolate the battery or is there still a drain on it. Also can the jump point under the hood be used to charge the 12v battery. I've been working on cars for over 60 years but with all the electronics on this car I'm very weary of doing damage in my attempt to learn how this car works. Please bear with me if my questions seem simple.Thanks for all the help Don
Don. You can charge the battery from the jump point under the hood. At the jump point if you undo the nut that holds the battery cable you can pull the cable eyelet up wards off the bolt. This has the same affect as disconnecting the battery at the rear, but is easier to get at. You can still then connect your charger to the eye terminal on the cable to keep the battery charged. This does stop all possible discharge routs. If you disconnect the battery in the rear of the car and shut the tailgate you cannot open the tailgate from outside. The single biggest problem with the Prius is reverse connection of a jump start or charger "less so with the charger". The maximum charge rate is 4 amps. It's the apparently simple things that can bring trouble. John
Don have you checked with your local dealer to see if your pump was changed under the recall. It may be that the dealer will replace it free of charge if it was not done. John
watch this video and save their website, a lot of great info and DYI videos VIDEO - Gen 2 Prius inverter water pump P0A93 - Luscious Garage | Hybrid Specialists Luscious garage or just look them up on youtube or google remember if you disconnect the battery in the trunk you cant open the hatchback from the outside
John It's not eligible according to the Toyota web sight. The replacement doesn't look to hard getting the air out should not be a problem thanks to Pat Wong instructions. I won't be getting to this job until next weekend. I just replaced the 12v battery, so my concern is by not running the car for over a week the 12v battery will go dead. I'll hook up my smart charger and keep it happy.
If you are going to hook up a 12V charger during the next week, then you don't have to worry about disconnecting the 12V battery from the Prius electrical system. Because it is easy to disconnect the + terminal at the dedicated jumpstart position in the main relay/fuse box next to the inverter.
Why so much concern with the 12V battery? Turn off the SKS and it should be fine for weeks. One week shouldn't be a problem at all, even with the SKS on. I leave my SKS on at the airport all the time for one-week trips. Removing the negative cable in the battery compartment is pretty easy, though.
Thank for all the great advice. First of all let me explain ... this is my partners car. It has 79000+ miles and it's time that things begin to happen for example the inverter coolant pump. In an attempt to save money on repairs I have gone back into the car repair business as a shade tree machinist. If this was a plain old car like my Ford Ranger there would be no problem but this thing is so full of electronics ... well buzz boxes and me just don't get along. I'm afraid in my attempt at some repairs I will be doing damage to the electronic. So I'm attempting to learn as much as possible about this car . Every time I learn something new another question comes up. Such as. When charging from the jump point under the hood should the positive terminal be removed from the past? This should isolate the battery and prevent back feeding any other components with charging voltage? Is it necessary to isolate the battery? Should I be worried about this? Thanks again Don
If you meant to say "should the positive terminal be removed from the post?": no. Seems to me if you disconnect the positive cable from the battery, you've broken the circuit: if you hook up a charger under the hood the electrons are not gonna make it to the battery. Per Frodoz, if you want to isolate the battery, isn't it traditional/safer to disconnect the negative terminal? I'm not sure why, but this is what I've always heard.
No you do not need to remove the positive terminal at the jump point to isolate battery. You can safely charge the battery with the car off and the charger connected to the positive (+ or red) jump point and the negative (- or black) connected to an engine or car frame bolt.
I assume that "past" is intended to be "post". The answer is no. If you want to isolate the battery, then disconnect the cables at the battery. The reason to disconnect the battery negative cable first is because if the wrench touches the body, nothing will happen. If you start with the positive battery cable and the wrench touches the body while the negative battery cable is connected, that will create a big electrical spark. No, this is unnecessary and you should not be worried.
