Took an LR3 out today and one of the turn signals was faster than the other. All of the bulbs were working. Probably a simple thing but I can't turn anything up with the search. Is this a sign of something more going on with electrical? Just wrong bulb maybe? Thanks.

 

Many designs of flasher depend on the current in the bulb path to control the speed of the flasher. So if one bulb out, and current drops, flasher will usually not blink, to inform driver. Of course, being Rover owners, our electric window may not work and we can't give a hand signal at that point to the dump truck rapidly filling our rear view mirror....

You would be correct that if mixed types of bulbs were used, the current drain can be different, and sometimes from various factories. Also, could be an indication of build up of corrosion around the socket, either to ground (increase current) or just on bulb terminals (increase resistance and lower current).

So you might want to remove each bulb and inspect, clean with small wire brush, etc. If in an area with road salt or sea salt, or if you take the truck wading, consider some type of bulb grease, from plain old vaseline to dielectric. This will reduce corrosion.

Your existing problem, if caused by corrosion, will continue to grow at a slow pace.