My 2001 Grand Caravan is having issues. When I turn my exterior lights on it goes into fail safe mode. If I turn my heat on it goes into fail safe mode. My engine also overheats adter about 30 minutes of driving my fan is working. I have taken it to a transmission specialist three times and they tell me its electrical so I take it to a electrical specialist and they tell me they have no idea what's wrong. That's after they kept it for three weeks! Please any advice would be greatly appreciated!

 

Do you notice headlights, interior, dash lights dimming as you turn on the A/C or blowers? I take it your battery has passed a load test and the battery cables have passed a voltage drop test and shake test. Did they verify a tight clean power connection from the battery at the IPM (fuse box) and ground connection elsewhere (??). Did they verify the alternator is producing enough voltage (~14vdc) to charge the battery?

The IPM is infamous for corrosion problems. I would take a look at the connections on the bottom and inspect for corrosion or any other damage. May be worth a look inside too. If all looks good and basic battery/charging functions are good it may be the TCM isn't handling normal voltage fluctuations and is cutting power to the EATX relay when it shouldn't. Verify connections are clean and tight then consider a new TCM. You could try the routine input output sensor change option but if your speedo is steady that's a doubtful fix. No codes right?