Narrative:

Airplane had just come out of an a check. Departed ZZZ uneventfully. When we got to cruise; we turned on the light override in the cockpit. A few minutes later; I realized that I had both bus a tie isln lights; both gen drive lights and all the window heat lights displayed. There were no associated EICAS messages for any of these. We were over the water; so we got a clearance towards land and started the APU. I had the first officer fly and do the radios while I contacted company on satcom. I spoke with dispatch; maintenance control and a duty pilot. No chief pilots were available. I looked through the QRH; but following it; would have directed us to disconnect the generator drives. That wasn't what we wanted and would have been detrimental in this instance so I decided that since everything seemed to be working; I wouldn't follow it. The decision was made to divert. We set up to land in ZZZ1. [We advised ATC]. On the descent when we turned the lights override off; we realized that was the reason for the faulty indications was the light switch. After landing; local maintenance found that incorrect led bulbs had been installed in these switches causing them to illuminate when the light override was selected.

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Original NASA ASRS Text

Title: B767-300 Captain reported incorrect bulbs were installed in cockpit switches; causing lights to illuminate incorrectly and requiring a diversion.

Narrative: Airplane had just come out of an A Check. Departed ZZZ uneventfully. When we got to cruise; we turned on the light override in the cockpit. A few minutes later; I realized that I had both Bus a Tie ISLN lights; both Gen Drive lights and all the window heat lights displayed. There were no associated EICAS messages for any of these. We were over the water; so we got a clearance towards land and started the APU. I had the First Officer fly and do the radios while I contacted company on SATCOM. I spoke with dispatch; Maintenance Control and a duty pilot. No chief pilots were available. I looked through the QRH; but following it; would have directed us to disconnect the generator drives. That wasn't what we wanted and would have been detrimental in this instance so I decided that since everything seemed to be working; I wouldn't follow it. The decision was made to divert. We set up to land in ZZZ1. [We advised ATC]. On the descent when we turned the lights override off; we realized that was the reason for the faulty indications was the light switch. After landing; local Maintenance found that incorrect LED bulbs had been installed in these switches causing them to illuminate when the light override was selected.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.