Hey Bill –
I recently bought a 1978 Lincoln Mark V Diamond Jubilee Edition and there seems to be an issue with the lights. All exterior lights work and most of the interior except the instrument cluster. Not sure if there is a fuse for those lights specifically… I did change a fuse that said “inst. cluster” but it didn’t seem to do anything besides stop my clock. All the warning lights work as well as the miles-to-empty gauge. So all the lights work besides the instrument cluster which wont light… Id appreciate any advice you can give me.
Thanks – Rocco
Hi Rocco –
Nice cars those Marks. The Mark V is becoming quite popular among collectors. I can help you get started on diagnosis by explaining how the Instrument lighting is powered. The power for these lights does go through a small fuse in the fuse panel but this power originates at the instrument light dimmer that is integral with the headlamp switch. Possibilities for your issue are that the dimmer is merely rotated to the Off position or that the switch and rheostat itself is faulty. The above are only suggestions based on your information that must be verified with diagnosis. We can offer to test and repair your switch if necessary if you are unable to.
For DIY diagnosis you will require the Shop Manual, wiring diagram and a 12v test light. We usually have manuals and diagrams available . Trying to repair the electrical without some meaningful diagnosis usually results in frustration along with wasted time and parts.