Electronic problems when interior of car hot

When my 2000 stratus ES car interior is hot, these symptons occur. These symptons occur whether engine is cold, warm, hot.The security system deactivates. Doors will not unlock when button on key depressed. Car will open only with manual entry. The odometer reads 0 and will not advance. The tachometer, temperature gauge, and speedometer are not responsive. The display to indicate transmission gear does not display, the transmission behaves normally. The windshield wipers will not work. The blower works. The air conditioner will not come on when the button is depressed although the light indicates it is on. The headlights, power windows, lock switches, and radio work. The selector switch to divert the blower air will turn, but whatever setting it was on when car last ran is all I get. The car starts and drives normally.

When interior cools down all functions return.


I am searching for a solution to similar problems that arise sometimes when outside air temperature is reported above 97oF (36oC). I have been informed by an UNreliable source that they suffered similar symptoms several years ago, and solved the problem by tightening each of the cable connectors, under the assumption that thermal expansion was opening the connections.

I have not yet been able to trace cables to attempt reseating connectors.

If you attempt reseating connectors, please post the results here.

Vent visors installed on my car have reduced the interior temperature by at least 20oF (thermometers that used to break at temperatures above 132oF displayed during the week following installation no interior temperatures above 112oF.).

Do you put a reflector in the window when you park the car in the sun? [yes]
Do you leave the windows cracked when you leave the car in the sun? [yes]
How much of the dashboard is exposed to the sun,
REAR of the windshield AND FORWARD of the reflector? [less than 5mm]
What temperature does a thermometer left on the passenger seat report? [100-122oF]
What temperature does a thermometer between the windshield and reflector report?
What outside air temperature does the car’s thermometer report? [97-107oF]

The prior owner of my car placed a reflector all the way forward using 1cm standoffs to prevent the reflector from getting caught and tearing in the defroster vents. I use a more convenient 5cm PVC pipe. The pipe exposes about ~3cm of dashboard to sun between the glass and reflector. The “instrument wire” and connectors to dashboard electronics are located near (within 8cm) of the exposed dashboard. At the suggestion of the prior owner, I am now placing the reflector further forward, to see if this makes a difference, within the next 14 days.

If all these things go out at the same time then I would search for a common power connection problem to those areas. The locks should work at all times so the ignition switch area isn’t at fault. The trouble will most likely be tied to a fused circuit under the hood that has continuous power. Having a test light probe to check for power would be a good thing to have on hand.

I Would Suspect The Large Connector At The BCM (Body Control Module) While Hoping The Problem Isn’t In A Printed Circuit Within The Module. Sometimes Light Corrosion Causes A Connector To Become Intermittent.

Sometimes just unplugging and replugging the connector works. A light application of dielectric grease would probably prevent corrosion.

I’d catch it in the act. Expose the BCM / BCM connector and let the car stew in the heat. When it acts up then wiggle the connector and retry everything.


Unable to determine from the Toyota Avalon service manual, any way to access the connectors without removing everything from the center console forward, I watched a professional mechanic remove and replace the Multi Information Display with ~10min of dashboard only disassembly. I hope I learned enough to reseat the connectors myself, when the problem reappears, as coworkers predict, in a few years.

See Repair and Maintenance topic “overheating dashboard electronics” (http://community.cartalk.com/discussion/2276766/overheating-dashboard-electronics/p1) for details.