Hello,

I drive an '02 Subaru Outback with a manual transmission that I bought last August. When I bought it, it started overheating on short, city trips so I took it to a mechanic and they told me that someone had replaced the relays but stuck them in the wrong spot. They fixed it for me and it hasn't overheated since. I mention this because for the past month or two, maybe even longer the blower for the AC/heat will fluctuate a little, especially when it is on full force and at night you can see the interior display and headlights flicker a little too. This happens when the cooling fans turn on and off which they do pretty regularly when I'm at a stoplight. Maybe every 30 seconds or so. When they turn on the idle jumps to just under 1000 and when the fans shut off it drops back to to 600-700. Sometimes the car will shake a little when it does this but it hasn't stalled. I took it by AutoZone and they tested my battery/alternator and both were good. The person who helped me thought it was probably an electrical issue or the motor for the radiator or condenser but didn't have the tools on hand to test further. Is it possible to diagnose this and fix it myself? Is it something to worry about at all? If I need to take it to a shop, what would be an acceptable price range or are there any common, expensive problems that I definitely don't have? Not entirely sure I have a mechanic I trust and while I'd like to learn I don't know a whole lot about cars. Car does not hesitate to start and has no noticeable issues at speed, this is all just happening at stop signs and stoplights.

Thanks!