Turn Signal Converter

Vibration or voltage would be my guess I'd change them over to LEDs as an easy attempt to fix this.

I'm not an electrician or auto mechanic, but have you considered vibration? Although auto bulbs are pretty resilient, the filaments will break under a lot of vibration. Had this problem on an old pickup many years ago. Check your installation and make sure the bulbs you added are firmly attached to the housings. Just my $0.02.

Dave

jeffo,
Well, this is a bit odd. I'm not a fan of adding additional bulbs and sockets but, that's just me. I've wired the stock bulbs to work just fine for over 25 years on seven different Jeep Wranglers with out issues. But, it's up to the individual to choose how he want's it done.

Now, you say it ALL works fine, until you blow bulbs. Well, obviously something's possibly shorting out at certain intervals. I don't think anything is getting too much voltage because, 12V is 12V and there is no more than 12V in those systems. So a short sounds like the possible answer to me. But, why at intervals? I mean, why does it all work fine and then, the bulbs are out?

You also say your rig has "Amber" turn signals. I'd just about bet my house that you already have a "three wire to a two wire" converter inside the coach wiring prior to the plug on the coach. Just about no 7 pin plug is wired as a separate right turn and left turn, with a dedicated brake light wire. So, if you say that your system is working "FINE" until the bulbs blow, then you're getting the correct signal to the newly installed bulbs. That is, a RT/brake and a LT/Brake.

Now, there is a possibility that maybe your converter is shorting out and causing the bulbs to blow? Sure it can. It's electronic and, is quite capable of screwing up. They don't goof up very often but, it happens.
Scott

Verify that the seven pin is wired so that the turn signals and brake lights come off the same pin for left and right.
I am guessing that there is no turn signal converter installed. You will need a three to two converter.