Bad speedo and oil pressure senders -- underlying electrical issue?

On a recent (2000 mi!) road trip, my speedometer/odometer suddenly stopped working. Around the same time I noticed the oil pressure gauge was acting erratically. I confirmed through tests that both sender units were bad, and I now have the replacements. My question is this: could there be an underlying electrical issue that caused these components to fail (like a bad voltage regulator?). These parts are expensive, and I want to eliminate the possibility that there's a deeper issue before I reinstall them, lest I have to replace them again.

On the other hand, the car ('87 3.3 coupe) has 55K mi and these components do have a tendency to fail, so maybe it was a coincidence that they both gave up the ghost on the same trip.

Thanks in advance!

 

Interesting. I'm hoping I've got the right part with my 3.2. But I doubt it'll be a 45 minute job because I'm probably going to have to fabricate a tool to access the hex fitting. Maybe the sender is in a more accessible location on the 3.4 motor.