1970s 1976 Cadillac Eldorado Headlights - Hi-Beam

[amarzano]

This is going to be a one-step-forward, one-step-back story.

I replaced the carpets in my Eldo. It all went well, but afterwards I noticed my High Beams no longer function. The low beams function normally, and the high beams will occasionally flash when depressing the floor dimmer, but will not stay on. 

My car does have the Twilight Sentinel option. I assume that if the low beams function, the dash switch must be okay.

That leaves the floor dimmer or possibly the Sentinel unit behind the grill. I removed all 4 connectors from the floor dimmer and cleaned the contacts, no change. Again an occasional flash of the high beams, but they do not stay on.

Any suggestions as to the culprit part for this failure? My first guess is the floor dimmer. Anyone happen to have a working unit for sale?

Thank you,

Alex

[Big Fins]

Back up. Let's determine what you actually have. The GuideMatic auto dimming feature, the Twilight Sentinel or the combination of both.

The GuideMatic has a sensor in the grille. The Twilight Sentinel has the sensor in the left front speaker grill. Of course, having the combined system means that you have both.

You also mentioned a 4 connector plug on the floor switch. This indicates the GuideMatic system if I'm correct. I would have to look. Your shop manual can confirm this.

The dash switch also has 2 rheostat rotating adjustments. The upper one is for the auto dimming and the lower one is the timer for the lights after shutting off the vehicle.

Check www.partsgeek.com  to see if they have the floor switches. I got mine there and I only have the Twilight Sentinel. OR... just remove your original switch, open it up, clean out all of the old hard grease, clean the contacts, lubricate it with dielectric grease, put it together and put it back in. It also has to have a good ground to the floor.

[Big Fins]

Twilight Sentinel wasn't available until 1964. I'd consult the 1961 Service Manual.

Huh? We're talking about a 1976 car. Where did you get 1964 from? Or am I skim reading something?

[amarzano]

[yes my car has both options. The dimmer has the 3 prongs on one side and an additional prong on the other. I did remove the connector's and clean the terminals. That did not resolve the issue.

These dimmers are not easily obtainable from the usual sites.

I'm looking to see if zip on the correct path with my trouble shooting and if so, does anyone have a working unit for sale.

Thank you

Alex

quote author=Big Fins link=msg=571474 date=1753108204]
Back up. Let's determine what you actually have. The GuideMatic auto dimming feature, the Twilight Sentinel or the combination of both.

The GuideMatic has a sensor in the grille. The Twilight Sentinel has the sensor in the left front speaker grill. Of course, having the combined system means that you have both.

You also mentioned a 4 connector plug on the floor switch. This indicates the GuideMatic system if I'm correct. I would have to look. Your shop manual can confirm this.

The dash switch also has 2 rheostat rotating adjustments. The upper one is for the auto dimming and the lower one is the timer for the lights after shutting off the vehicle.

Check www.partsgeek.com  to see if they have the floor switches. I got mine there and I only have the Twilight Sentinel. OR... just remove your original switch, open it up, clean out all of the old hard grease, clean the contacts, lubricate it with dielectric grease, put it together and put it back in. It also has to have a good ground to the floor.
[/quote]

[Eric DeVirgilis CLC# 8621]

Huh? We're talking about a 1976 car. Where did you get 1964 from? Or am I skim reading something?

Disregard.

[Eric DeVirgilis CLC# 8621]

I have the opposite problem in a 1977 in which it's very difficult to switch from high beam back to low. I'll probably have it bypassed altogether. I hardly ever use it as it never worked very well, even when operating normally.