98 F150 4.6L S/C 4x4 Manual 5-Spd, 346,000 Km - Just started today, didn't notice a serious miss with engine, but both the low fuel (yellow) and low oil pressure (red) flashed on simultaneously a few times, all for short times (second or two), while driving at city speed or less. Don't see a lot of similar threads out there. Oil/Filter and Fuel Filters were recently changed.

 

Neither filter would have anything to do with the lamps or you would have engine drivability issues.
Both lamps are supplied a ground from a solid state chip that has inputs from both systems.
That chip grounded both lamps for some reason.
Not likely to have an issue in two areas at once without serious engine results.
Likely a dash issue.
See pages 12-20/21 in a Haynes repair manual for the above layout.
Good luck..

 

low oil pressure will cause the motor to get noisy, so I agree that it is a dash problem too.

 

Thanks for thoughts on possible dash issue. Ran a scan with wifi reader, no error codes on any of the systems either. Haven't seen the issue since. Will look at that chip diagram though.

 

Call it an opinion or call it experience but I'd bet money yer gonna be looking for a new alternator soon.

 

Thanks for the note on the alternator, luckily I recently picked up a new brush set. That cheap replacement saved me on another alternator, different truck, that stopped charging this past winter. Have time to do the brush change, as I'm waiting to find a spring hanger that broke last week (hard to find any decent price on parts in Canada, usually ship from US)

 

Ok, so I waited on the brush change, but lights flickered quite a few times last trip (it hadn't for a few months), and luckily I made it home. So I finally pulled the alternator and removed the brushes. Sure enough one (furthest in) brush spring was maxed out, worn at least 1/8" further than the other. Will replace with the brush set I was carrying in the glove box. Hoping the regulator is fine. The pulley felt fine. Some other good timing, in removing the carb cover I found my throttle cable starting to fray.