"Auto Dimmer" Repair Information for Your Imperial

Imperial Home Page -> Repair -> Accessories -> Auto Dimmer

Tip from Timothy:

Auto Beam Changer: Should dim you lights for oncoming traffic (and roadway signs that are highly reflective and a few other things). The senor eye is the lovely sci-fi-esque thingy standing up on your dash. The sensitivity control is a knob on the back of the sensor unit. On my 60, you turn the knob to the right to make your lights dim sooner (more sensitive) and left to make them dim later (It is best to make these adjustments with the car pulled parked on the shoulder of a nice two lane highway at night). You can override the system at anytime by using the foot switch. To go back to automatic you just hit the floor dimmer again.

Question from David (1965):

I have a 65 Imperial with auto dimmers that will not respond to the manual override switch in the floor. I have replaced the floor switch but still the dimmers work only on automatic and cannot be forced to dim manually. Can anyone help?


From Norm:

If I remember correctly, the floor switch may be a different kind. I seem to recall reading in a manual somewhere that in order to activate the system you had to press the floor switch half-way down, which somehow engages the system. Now, it seems to me that if I recall this fact correctly, there must be a different floor switch used with some kind of intermediary position(and wiring for it) to accomplish the aforementioned objective. As always, when dealing soley with unaided re-call, I could be WRONG. Check it out just in case.

I am not entirely certain, but I seem to remember that the book says you have to "set" the system by pushing the floor button halfway down and releasing . This is done when the headlights are first turned on and seems to tell the system something it needs to know in order to operate properly. My current 66 convert has the system but it is not working so I cannot test the theory. I seem to remember that my last 66 had the system and it did, indeed respond to this regimen.

From Ed:

Recalling my long ago experience with things electrical (P-51 Mustangs in the 1950s), I am pretty sure that the floor override switch does no more than "bypass" the dimmer system. I would get someone with a meter to locate the wires that come from the high and low of the lights, and the manual override floor switch, and connect them in such a way as to bypass the dimmer system. Then work backwards from that to bring the dimmer system on-line when the floor switch is disengaged from "manual on."

From Dick:

I don't have access to a schematic of the system, but from your symptoms, I'd check the wiring from the floor switch to the control box for the SS system. It appears that the control box doesn't know you are changing the setting of the floor switch. If you have the FSM, you should be able to buzz out each wire individually to make sure all is connected properly.  Just to nit pick a little, I think you are asking about the Automatic Headlight dimmer option, not just the Safeguard Sentinel option.

Question from Kerry (1964):

Driving today in the rain with the headlights on in the 64. Noticed this clicking every 30 seconds or so and realized it was the headlight relay cycling the lights. When I got home and parked where I could see the lights I noticed they were going from high beam to high beam with a 2-3 second no light interval. I have the auto dimmer set to max and a piece of electrical tape covering the eye. I even tried putting my finger in front of the eye, no change. How do I just bypass the dang thing, or rather, can I bypass it?


From Dick:

I'm not sure on the early ones, but later on, just selecting low beam with the standard dimmer switch would turn the system off. If that doesn't work, take the fuse out of the power feed to the amplifier.

From Dave:

I went to look in my 65 owners manual (the FSM is with the mechanic right now), but it did not say a whole lot about the dimmer. The owners man. does say to turn the knob to the right to increase the sensitivity. I don't know if this will help but it can hurt.

From Jay:

I had a similar experience in our '66 with AutoDimmer on a not-so-straight two lane mountain road on a moon-less night.

When faced with large reflective road signs around a sweeping curve, my own high beams bouncing off the sign got the AutoDimmer into a fast cycle "high-low-high-low" action that ended (after about 1 1/2 seconds) with an "all lights out".

I was doing about 55 through the sweeping turn.

It got SO dark SO fast that to this day I swear that it turned off ALL the lights including the instrument panel! Doesn't seem possible, but it was SO dark that it seemed like I closed my eyes (would I dare blink in that situation?).

I got to that floor switch so fast and started pumping the dang switch trying to get some light back on the road. I did, but it took me quite a while longer to get my heart pushed back down out of my throat.

My family slept through the incident (thankfully).

I never got the solve the problem, but my guess is that the dimmer relay has some sort of circuit breaker that trips when overloaded/overheated.

Be careful with your AutoDimmer when going "rural - at speed."

Question from Henri (1965):

What is the torpedo shaped thing on my dashboard? I  really can't find out.


From Neal:

If that "torpedo-shaped thing" is like mine, it is the automatic headlamp dimmer. According to my owner's manual, when you turn them on, the headlights should default to high beam The dimmer will dim them to low beam when it senses bright lights, like street lights or on-coming cars. Mine still works pretty well, but it's annoying when it constantly goes on and off. You can override it by using the foot dimmer.

From Bob:

There should be a way to adjust both the "dim" and "hold" time. On GM products with Autronic Eye, there is a box on the driver's front wheel well towards the firewall that you can remove the cover and adjust either one. I'm not sure how Chrysler's work.

Question from Allen (1969):

I recently bought on Ebay an Owners manual for my 69 - had never seen one before - it answered a question I had - if you have the auto headlamp dimmer, it illustrates that the same delay switch for the twilight sentinel operates it. I don't remember anyone telling me this! Now I know mine never had this option.

Reply from John:

Behind the sentinel delay knob, there is a lever that adjusts the dimmer sensitivity.

Question from Eric (1966):

Help!! I think that my headlights are possessed. Both dim light work fine, but when I turn the brights on, the drivers side dim light goes out, and the driver's side bright light doesn't come on. Both lights on the passenger's side come on though. Sometimes after pressing on the dimmer switch to turn the brights on it returns to to dim position. Is this a problem with the switch, or???


From Dick:

The outer bulbs have two filaments. When you switch to high beams, the "dims" are supposed to go out. The reason your outside left bulb goes totally out when you switch to high beams is that the high beam filament is not lighting, probably because the bulb is partly burned out. If neither left side bulb lights on high beam position, either both bulbs are bad or you have a wiring problem. The dimmer switch is connected to both sides of the car, and since the right side is OK, the dimmer switch must be OK.

The business of it returning to the "dim" position after you have switched to brights is possibly your automatic headlight dimmer just doing it's job (if your car is so equipped)- it is enabled when you switch to the brights, and if the sensor sees a source of light that is bright enough in front of the car, it will dim your lights automatically. If this is your situation, the next time this happens, put your hand in front of the automatic beam sensor (the thing with a lens facing front, probably on your dash board [not sure where it is on a 66??]) and it will switch back to high beams as soon as you shield it from ambient light.

If your car is not equipped with the automatic beam changer, then I'm all wet (again), and you've probably got a bad dimmer switch.

From Gary:

I have had this problem before, my problem was found to be with the headlight switch itself , when I hit the dimmer switch my lights would go out and only have dim lights, it was found that the light switch on the dash (Through age?) would no longer handle the full power of all lights on any more, I put in a relay and it cured the problem permanently, this was successfully done with a number of my cars, this is not to say it could not be something else, it may be the dimmer switch, does your model come with factory fitted relay?

From Steve:

I'd replace the dimmer switch and check connections to it. If it is anything like mine, it is inexpensive and cheap insurance against an old one going bad on some dark, back road. If it returns to "dim" on it's own...it is faulty and not clicking all the way thru. Check the connections/plugs on the back of the headlights for corrosion and looseness. Check the headlights for broken filaments by either looking in the bulb for broken ones or by using a multi-meter. If all is ok, check for power at the headlight plugs. It sounds like you have a bad switch and a bulb or two out.

From John:

I would say that the lights not working correctly have one of their stages burned out. Replace those & all should be fine.

Question from John (1981-1983):

Could someone could tell me where the high beam headlight switch is located?

Reply from Dick:

I see you've received answers to all your questions, but I wasn't clear if you were asking how to operate the headlight dimmer control, or where it is physically located. In case your query pertained to the latter, it is mounted on the steering column down near the floor. It is on the upper surface of the column, and you need to remove the access panel described in the other responses, then slither in there on your belly and look above the column. The dimmer switch is operated by a long metal rod which moves up or down in response to pulling on the turn signal lever. The mounting screws are in elongate holes for adjustment of the switch.

Question from Erik (1967):

My new Imperial has no headlights, tail lights, or dash lights. I assume this is the headlight switch. I went to every parts house in the Eugene-Springfield area today, trying to find one, but no luck. Where should I look? Will switches from any other year or make interchange with the 67?? Thanks for your input.


From Dick:

It could indeed be the switch, but if it is, it can be repaired. If you are not comfortable doing it yourself, there are others on the list that will repair it for you (myself included).

But, before you go to all that trouble, check to see that your twilight sentinel (if equipped) is not causing the trouble, and that the circuit breaker is not open. If you have an FSM, these parts will be easy to check. If you don't, I'd advise getting one. These cars are very complicated electrically, it is virtually impossible to repair them without a manual.

From John:

I had this problem on a 60 & it turned out to be the high beam switch was bad.

From Chris:

I'd suspect a couple of fuses (or simply a disconnected headlamp switch) before I sought out a replacement switch (which, by the way, can be from a '67 or '68 Imperial but nothing else). It is odd that all those functions would go out together (and unlikely that the previous owner let all of them fail one at a time).

The switch is fairly easy to get at. You need to remove the instrument cluster, which means about ten screws, disconnecting the cable behind the speedometer, and unplugging a few connectors. Once it's out, I'd remove the headlamp switch from the instrument panel and reconnect it, checking for loose or dirty connectors and jumping the wires to see if bypassing the switch illuminates the lights (sorry, don't have the schematic handy but I could get a copy of it to you in a few days if needed... I recommend buying a factory service manual).

If you have twilight sentinel, this could be the culprit, too.

And I'm sure one of our vendors on the website (Bob Hoffmeister, Murray Park, etc.) can find you a switch if you end up needing one.

From Ron:

Your choices are either 1967 or 1968 Imperial and several years of Chryslers "C" body switches. 1967 and 1968 Chryslers, Plymouth and Dodges also used the same type flip switch for the headlights. Obviously, these are more common in the salvage yards.\

From Bill:

A switch from a 68 will fit a 67. Does your car have the auto dim and the sentinel? If so, this might be your problem.

This page was last updated on December 5, 2001. Send us your feedback, and come join the Imperial Mailing List - Online Car Club