I have a MIA Hotrodded P-Bass. I changed my strings 2 days ago from Fender light/medium to Ernie Ball heavy/medium. I discovered that with the Ernie Ball strings the neck has more relief and higher action. I know that adjusting the trussrod will correct the relief but I have never attempted that adjustment before and there aren't many guitar techs where I live.

My question is should I just change strings back to the gauge I used before or attempt to do small trussrod adjustments? If I leave the Ernie Ball strings on will it hurt the neck?

I agree with GlennW..

This is going to happen any time you change gauges of strings, and it's going to be more noticeable when you have only a small amount of relief and low action.
Those heavier strings are pullin' more tension for the same tuning.
Here's a couple of tips... make a small mark on your truss nut so you'll know just far you've actually turned it. This really helps, especially considering that you'll probably have to make more than one adjustment.
I believe in loosening my string tension when "tightening" a truss. Others will surely disagree, but turning a truss nut with all that tension on it could possibly cause it to strip.
If you ever try to turn the nut and it's really tight, not wanting to budge, don't force it. That's a good time to see a tech and get this figured out.

Good luck , and you should have her playin' nicely in no time..
Mag..

Thanks for the tips. I detuned and tightened the trussrod about an 1/8 turn last night and tuned back up and let it settle in overnight. It seemed to help. I'll check it again tonight. I was wondering because I was really wanting to check out how those EBs sounded on my P-Bass and didn't want to just "deal with" the higher action.

This was a common occurance for me until I found a brand and a guage I liked. The two gents who answered are dead on. Just be patient, don't force anything, and it will work out. I think I had about 2 months where I was adjusting the rod 2 or 3 times a week with string changes every 10 or so days. I eventually settled on one of the lightest guages I could find and had to back the rod off almost 1 1/2 turns.