2001 Prius speedo MFD disappearing

[windshearalert]

Good morning everyone. I have been reading the forum for quite some time and picked up some great information. I wanted to tell everyone about the 2001 prius I picked up about 2 months for a coworker. He was getting ready to retire, and just bought a new subaru Forrester. His 2001 prius has always been a topic of dicussion during our lunch breaks, so he offered to sell it to me. He purchased the 2001 from California brand new. He is a stickler for detail. It has had every service done at the dealer, and looks like it is completely new. Perfect interior, cold AC, clean as a whistle. Now for the bad. Or maybe not so bad.... It has 225,000 miles. Now for the good....I paid $1500 bucks for it and up until today has ran like a champ and rewarded me with 53 MPG each fill up. Prob 50/50 hiway city driving. Im very impressed with this little car! I am an aeronautical engineer so I have absorbed everything from the forum. Here is the good. He had a new HV battery pack installed 1.5 years ago. (Has about 25k miles on pack). Engine was replaced 3 years back at 160,000 miles) It runs and drives perfectly, until tonight.....
Here is what happened. Tooled over to a friends house and swam at pool party. When i got back into the car, it started fine, backed out driveway, turned on headlamps....and i looked over and no speedo? Digital numbers inop. MFD was "dimmed" down and looks like color was washed out of it also. Working, but just dimmer than normal. Turned lights OFF, ad speedo came back on! MFD brightened up back to normal. Turned lights back on and speedo went blank once again. Oh MFD also went back to dimmer output...All is fine when lights are turned OFF. Its still running fine, hell it pulled damn near 60MPG drive back to house (MFD was dim, but i could still see readout, and no speedo) Now in the speedo cluster, the headlamp icon and turn signal icons worked fine. As did the cold coolant icon until engine warmed up.
Headlamps didnt seem to be dimmer than normal, but the lenses are a bit hazed from age, but seemed normal. I got home and double checked the headlamp switch, indeed, when turned to ON, the speedo inop, and MFD dim. LIght switch off, MFD and speedo fine.
Do you think this could be a case of a bad 12v battery? I see it is the correct toyota battery installed. Another question, What is the best way to check the SOC for the 12V battery? ANd what is the preferred method of charging it? Honestly, im a tad scared with using a charger until i hear from you guys on correct amps to charge it with. I am assuming 2A trickle, but wanted your opinions.
I do have both the service manuals from toyota. As i said previous owner was anal about the car and even installed a mag lite under the front seat just in case he needed it. For last 2 months this think has put my impala ss and silverado SS in the garage. I honestly have fallen for mileage over horsepower. I have enjoyed all the forum information thus far! (LOL if you are interested, the previous owner installed aircraft valve stem caps on the tires...I have had 3 people ask me about the caps....ill send a pic if you want to see em.. LOL lil aviation humor there for ya)
Any help /ideas would be appreciated!


Justin

[windshearalert]

Well its official....its fixed...and i am an idiot.... LOL....after thinking simple I went outside and rotated the dimmer dial back up to where i had a speedo and MFD with lights on.....shesh..... I had my 10 year old son vacuum it out earlier in the day and he prob played with the rheostat....

Well, least it didnt cost me anything but the rash ill get on the forum!

Go ahead.... this is the perfect opportunity to have fun at my expense!

Cheers!

Justin

[Ogo]

[patsparks]

Justin, that is the oldest trick in the book mate and you fell for it.
Buy your son a lolly pop.

[Patrick Wong]

Originally Posted by windshearalert

Headlamps didnt seem to be dimmer than normal, but the lenses are a bit hazed from age, but seemed normal... What is the best way to check the SOC for the 12V battery? ANd what is the preferred method of charging it? Honestly, im a tad scared with using a charger until i hear from you guys on correct amps to charge it with. I am assuming 2A trickle, but wanted your opinions.

Hi Justin,

Congratulations on your purchase. Regarding the headlight lenses, you may find that plastic polish will remove the haze.

Regarding the 12V battery, you are right that a trickle charge of 2A would be appropriate. Assuming that you have the correct GS or Panasonic 12V battery installed, if you look at the top of the battery you will see a warning label that indicates the maximum charging current to be applied, somewhere in the range of 3-4A. Regarding SOC, measuring the battery voltage after the car has been IG-OFF for a few hours is one technique. If 12.6V-12.8V then it is close to fully charged; while 12.1V-12.2V would be considered discharged. However, even if the battery voltage without load is at spec, this doesn't guarantee that the battery is working since internal resistance may hamper the battery's ability to perform under load.