INSTRUMENT PANEL ON 1977 LINCOLN MARK V DOES NOT ILLUMINATE

[OldSchoolLincolnGuy]

Hello everyone. Just bought a 1977 lincoln mark V. Love the car.

A problem that I discovered at night is that the instrument panel does not illuminate. The cruise control, radio, antennna, warning lights, signals, hvac, headlights all work. But the instrument panel does not illuminate. Checked the dimmer and it doesnt seem to work.

Looked in 1977 manual and replaced fuse 1 which is 6 amps for the instrument panel and it still does not illuminate. I am stumped. I want to avoid taking apart the dash.
If it was the bulbs some lights would work and some not or some would be faint. Not the case here.

Totally out here, anyone, please advise.

[Dan Szwarc]

The problem is likely the dimmer contact to the wire-wound resistor. Inspect the connection and make sure it’s not bent, damaged, or corroded.

You can pull the headlamp switch carefully and inspect the contact finger. Make sure it is touching the coiled resistor wire.

Report back what you found.

[TonyC]

That is one very possible option. However, that will involve infiltrating (for those in Rio Linda, that means "breaking into") the dash to access and remove the headlight switch for inspection. It can be frustrating if you go through all that and find none of those tell-tale signs.

I suggest starting simpler, like checking the fuse that regulates that circuit. If the dash lights do not come on at all, a blown fuse could be another culprit. As fuses are easier to reach than headlight switches, I'd go there first; identify the fuse that powers the dash lights, and pull it for inspection. If it's blown, replace it with the same kind. If it's not blown, then go after the headlight switch.

---Tony

[LithiumCobalt]

Tony, he already said that he replaced the fuse.

[frasern]

Most likely the switch, but possibly a bad printed circuit or the plastic housing on which it mounts. Where is the car from?
I recently took one apart, it is a little tricky but do-able, I will take a picture later today.

[John Mc]

Experience tells me 90% of the time the headlight switch is the issue. Unless, it’s an auto-lamp system, it’s a $30 part at NAPA. I would just change it.

[frasern]

Here is the back of the cluster, and the switch.

I think the switch can be removed from beneath, but not sure, The two upper terminals in the photo. can be seen going to the rheostat, power should be at both when the switch is rotated, if no power, the problem is before the switch, if everything checks out here, check the terminal on the back of the cluster, Left side, 3rd down.

I recently sold the speedo to a member in France, so I had these parts already removed for photographing.

[OldSchoolLincolnGuy]

I want to thank you all for taking the time to respond. I replaced fuse 1 for the panel lights. It didnt make any difference. I have a manual headlight switch not autolamp. My Mark V was a plain jane so it does not have additional power accessories that many are used to. How do you pull the headlight switch?? From underneath or unscrew the dash?? I am sorry if I sound like an idiot but I never did this before and I dont want to cause additional problems to the car. How do you test the switch/dimmer?? What do I look for on the switch/dimmer??

[Dan Szwarc]

I think headlamp switch removal is described in the shop manual.

It’s also been described on this forum in the past.

[TonyC]

Tony, he already said that he replaced the fuse.

Oh...

Right, I see that now, too late. Never mind.

[OldSchoolLincolnGuy]

I will probably replace the headlight/dimmer switch (seems to be the culprit 90% of the time according to others here. On Ebay I have seen them for about $49 free shipping and free returns, its worth changing. Also I need to fix the clock which does not work. Maybe I can lubricate it or at least bench test it. Called Clockworks place in WI and the guy there wants about $190 to repair, seems expensive to me. Maybe I can repair mine if I can. I will have to open the dash anyway might as well kill two birds with one stone, Lol. Thank you all for your guidance.

BTW. When I disconnect the old switch do I have to turn off the vaccum lines to the old switch or it does not matter??

[LithiumCobalt]

The Clockworks does good work. I have used them in the past. Surprised that they would offer to service your clock, though. Supposedly “the Cartier clocks were junk from the beginning and there are no parts available to fix them”. Direct quote from
Them when I inquired about the clock for my Mark III

[OldSchoolLincolnGuy]

Update fixed the rheostat part of headlight switch. Just needed electrical connection cleaner to clean the gunk and dirt around the rheostat and the dash lights illuminate! Didnt have to change the headlight switch or install dash lights. The original dash lights from when the car was built in 11/76 still work!

Exterior pic of car 1

Interior pic of car 1

Interior pic of car 2

[TonyC]

Very nice...! Glad all the controls needed was a cleaning. I have to say, the Mark IV wheel covers make your car look even nicer.

---Tony

[OldSchoolLincolnGuy]

Thank you Tony. Those wheel covers were standard on the Mark V. The Mark V had other optional wheels like the deep dish and turbine ones.