Engine running, when I move the key around in the ignition of my 95SWB, a relay or something behind the instrument cluster clicks. Occasionally clicks on bumpy roads too. Is it a bad relay or bad ignition switch?
I have that click too. This click is somehow related to the key in the ignition. With ignition on...push the key-click, pull-click, twist-click, hit bumps-rapid clicking, hold key firmly over bumps-clicking stops.
I've had it intermittently on my '97. And it doesn't stop even when truck turned off. Have to start truck again for it to stop. Read somewhere that it may be the alarm ECU (green box on bulkhead behind cluster). I've seen it - but I don't have an alarm.
Oops - just realized we weren't talking about a 90.