Rainbow 1 - only 1 pickup working

I have just acquired a Rainbow 1 and have discovered that when plugged in,I only get output to the amp from one pickup when flicking the 3 way pickup selector across the 3 positions

Is it most likely to be the 3 way pickup selector which is at fault or could it be a dislodged wire from the other pickup or a fault in the pickup itself?

Working on hollow bodies is not something I have done before so any advice would be much appreciated.

thanks

Richard

The same pickup across all 3 positions? First thing I'd be trying would be to shoot some quality contact cleaner into the switch, work the switch a few times and see if things get better. 
After that, on a hollow, I'm clean out of ideas - on a solid, I'd pull the switch and swap it for a known good one, then its the pickups; pull 'em out and check their output.

Yeah working on an electric hollow body can be a *ahem* challenge.

Do try the contact cleaner first. Most times oxidation is the culprit. But be sure to squirt it from the underside, don't hose it from the outside. To do that insert the tube through the  F-hole. The switch is fairly close and should easily be reached.

If that doesn't do it, you'll need a small inspection mirror to see inside to look for a detached wire or loose connection. Unfortunately, the only physical means of accessing the circuit components is via the bridge pickup opening with navigational guidance through the f-hole. Not a job for the faint hearted. It can be tedious to remove and replace everything.

Thanks for advice guys, I suspected it might be a tricky job!

p.s. If squirting the switch doesn't resolve the problem, before you take any of the components out, give the pots some as well. You should be able to at least reach the volumes. Might save you a headache or two.