Chriscolt

I own a 2008 RX400h and had problems with the radio/cassette/CD changer system on 2 occasions both times every day until I replaced the12 Volt battery. I have to replace the battery every 3 to 4 years since replacing the original battery from 2008. I have read that these hybrids chew through the regular 12 Volt battery. I recently had to change the Brake Control Power Supply Assembly (part in hybrids only - p/n - 89680-33010) under the cargo deck due to a "Yellow Brake Light" on before and after a complete brake job including new calipers (USD$1900 - yikes) because they were completely rusted/corroded through (3 of 4). Bought myself a scanner (CGSULIT SC510 Elite for Toyota/Lexus - Amazon for under USD$100) as Midas (service station that did brakes) said that they researched and light should go out by itself after 300-600 miles - nonsense. The error code C1377/108 indicates bad capacitor (indeed after I opened up the "BCPS" there is at least 1 very leaky electrolytic out of 2 banks of 6 unlabeled capacitors). I mention this because just having rear hatch open and the little dome-light on sidewall of hatchback so I could install new Brake Power Supply (took 3 hours) dropped my battery to under 50% charge, leaving radio on with car off for more than 45 minutes will prevent RX400h from starting, Indications that battery needs replacing 1) if it is 3 years old or older, Steering wheel power lift motor when u remove or insert key before starting engine starts Squealing, radio display starts to turn on/off by itself or radio completely shuts off while driving. Warning lights come on/off intermittently & I believe that a weak battery made have caused the Brake Control Power Supply to fail - since it depends on health of 12V battery to properly charge the 12 capacitors inside unit. Check Battery first - if not a maintenance free lead acid with removeable electrolyte covers - remove covers and check electrolyte especially on ends closest to negative & positive battery terminals - I bet these are very low - possibly showing battery plates - fill with distilled water and put on a HQ battery charger that slow charges the last 10-20% of charge (in my case a charger with a winter mode for charging when temps are below freezing) and replace battery with proper deeper cycle hybrid compatible battery. Weak/old 12V batteries cause many intermittent electrical problems with Lexus Hybrids that may falsely point to more complex/costly problems that are not real.