98 caravan. 3.0L, flashing indicator

a 98 caravan, 3.0L, after changing battery.
everytime, when the engine is started, some indicator lights on the button flashing continuously ( including A/C switch, air recircuration switch, rear wiper switch and rear wiper delay switch). it lasts almost 20 minutes, then back to normal. everything still works well. a/c, wiper..

anybody knows what 's going on?

thanks so lot

I'm not sure, but it sounds like something may be going wrong with the ECU.

i read the wiring diagram. it seems the lights are controlled by the A/C,HVAC control module. they are the LEDs. but i have no idea why flashing? it seems the problem of capacity. or PCM?????:banghead:

Take it to AutoZone or something like that and have them pull the codes...it's free.

as mentioned, there is a computer that controls the climate control system. When a code is set and/or the computer senses something very wrong in teh system, it flashes like you say.

Autozone or other part stores will not be able to read the code. They can only read OBD2 codes, and this will definitely not be an OBD2 code. Well....extremely unlikely anyway.

It could be many things wrong, unfortunately. It needs to be properly diagnosed

thanks everybody

according to the wiring diagram, for A/C control module, there is only one wire connected to the PCM. the A/C switch signal to the PCM. any idea?

thats the CAN bus....why do you ask?

The entire car is wired with a CAN bus....between the ECM, TCM, EVAC and BCM (whatever is applicable) there very well could be a CAN bus problem....but trust me, you don't want to even know what it takes to diagnose it.

you didnt by chance happen to hook the battery up reverse polarity and pop some fuses? check the fuses, make sure none are blown.

its step one in any electrical problem diagnosis