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Haunted Honda - Electrical Problem

Our 2002 Honda Accord is doing some weird electrical things in cold weather. My mechanic already replaced the ignition switch but it continues to have electrical problems in cold weather.

Here are the symptoms :

Oct. 26th - the back left window lowered itself when the car was turned on. I could not pull it back up from the front window control panel, but our daughter could from the back left door.

November 1st morning – The oil light flashed on and off, and when I stopped in a gas station to check I was only a quart of oil low. I filled it up, the light went off, but then started blinking and beeping the next time the car was turned on.

November 1st evening – I turned on the car and the back left window went down, the oil light flashed, the car beeped, and the windshield wipers turned on. Only after I turned the car off and turned it back on did I regain control of the window and the windshield wipers. The oil light continued flashing all the way home.

After the ignition switch replacement the oil light is still flashing and the car is making clicking noises. The back left window continues to open on it’s own when the car starts in cold weather. The mechanic now thinks we might need a new multiplex control box but he isn’t sure. Any thoughts on what the problem is would be appreciated.

Thanks for your help in exorcising the car!

An oil light does not come on when it is low on oil. It comes on when the pressure is low. The pressure can be low when the oil level is low but it could also mean that one of the engine’s passages is partially blocked or your oil pump is acting up.
After you added oil and the light going off makes me think that the oil pressure light is indeed indicating a real condition.

If you’re having two problems, I’d make sure that your oil pressure is indeed correct first.
After all, having a window open with a blown engine makes having that car moot.

The problem with the oil light and the window are most likely unrelated. The window problem is likely to be a short circuit. Unfortunately it sounds like the Mechanic you took the car to for the ignition switch is simply replacing parts. Take this in to a dealership or other skilled indpendent shop that knows how to diagnose and troubleshoot electrical problems.

You might even check to see if Honda has a TSB (tech service bullentin) published on this problem. Either way, a good tech will find this problem and not just replace parts

One thing that should be done whenever there are electrical problems is to clean up all grounding points. There could be one or two on the floorboard under the dash, these should be obvious because the wires are screwed into the sheet metal. Engine to body is another one which could cause a switch to have no effect. Battery cables could cause some of those problems too.

Thanks so much for the responses. The car is at the dealer today and have received no information yet.

I would first check the alternator for excessive AC ripple voltage. That might explain most of the troubles. The window problem is most likely due to a switch problem in the main panel.

Honda oil light will flash if there was a very short low pressure, less than 1 second. They feel you may not see the light on for this short time, so it flashes to let you know. This being said, a failing oil pressure switch can cause the same flashing light, and is the least expensive repair to try 1st. Your other problem does sound like a multiplex issue,but more diagnostics is needed.