If you wire the fan directly does it work? could be the connector to the fan is an issue. That's what I recently went through. Could also be the fan is just failing. To check my relay we used the DRBIII scanner and had it trigger the fan on etc. This way we could see if the fan was coming om as designed, and if there was an issue with the relay. Found one of my 'backup' relays was no good this way. Being intermittent though, I'm thinking fan or fan connector. I've only experienced the relay failing. Never being tempermental.
As for the overhead, had mine acting strange beeping low coolant when there was nothing wrong. Seems to have gone away. Not sure what's up with that. Don't think it's related at all though as it only goes to the float in the overflow bottle. If it drops too much as in fluid is too low, it'll trigger it to go off on the overhead. Same with the washer fluid, although the float is different.
The beatings will continue until attitudes improve!
HID Quad bi-xenon + foglight retrofit