I have a 99 Lumina, 3.1 and it was running ok with no issues except a very very intermittent starter/starter relay issue- 1 out of every 100+ starts it won't start the first time. (I'm planning on installing a new starter eventually). I parked it last week for 3 days while away on a trip. I return and the battery was stone dead. I took it out and recharged it (no bad cells found). Upon hooking it back up, the right fan turned on- not the left. It's never done this before. The keys weren't even in it and the fan should not have started. I began troubleshooting and removed each of the 3 fan control relays 1 at a time and only with Fan Control relay #2 removed, would the fan not turn on with the battery reconnected. So now with the fan not on, I attempted to start the car. The lights all worked, but the car would not start. I ran out of daylight tonight for further troubleshooting.
Any thoughts?

thanks!
John

 

I'm guessing seperate issues. I believe that one fan is designed to run even with the key off, until the temp is at a certain level determined by a temp sensor. It not starting would be another problem, but try putting the relays back where they belong first.

 

First , it sounds like you have maybe several electrical issues , posiably with the most severe causing the others ?

But here is a simple first try . I am betteing all 3 fan relays are the same ? ( my 96 Lumina only has 2 fans , yours has 3 ? ) Try swapping them out to see if you have a bes relay . Best I remember they are not too $$$ to replace & I figure your local parts store has them .

Next , if I remember correctly , the relays are not controled directly bu sensors . The computer reads the temp sensor or sensors and triggers the fan relayor relays . All this also depends on if the A/C is on or not . And if one or both fans are needed .

Or , lastly , something caused your battery to go down . If the relay is defective & turning the fan on , in error ? Or if there is a " computer / sensor " problem causing the relay to be turne on in error ?

What kind of temperature reading are you showing on the dash ?

God bless
Wyr