Fellow CLC members,
I "finished" my restoration of my 1958 Cadillac SDV 3 years ago, but of course, you're never really finished.
My latest project is getting the trunk tell tale indicator light to work. When I open the trunk and have the ignition on, the trunk light does not work. I checked the obvious - the bulb and socket were cleaned and tested. All of the wires are intact with no splits or cracks. The printed circuit board is also good.
According to the schematic in the shop manual, the trunk tell tale is the dark green wire and the manual just shows it going into the trunk harness.
My questions are:
1. Where does this dark green wire go after it plugs into the body harness? I see where it plugs in but I do not see it in the trunk.
2. What is the theory behind its operation? What goes on when the trunk opens to make this bulb go on?
Any help, as always, is greatly appreciated. Thank you in advance!
Matt
CLC #21633
Matt,
The switch for that light is in the lower pull down mechanism. The ’61 shop manual has a picture of the complete pull down unit in the body section of the manual.
The wire for the warning light is blue in the unit and becomes dark green on the body side of the connector in the trunk. I believe it will be the same for the ’57 â€" ’58 cars.
I don’t believe you need to turn on the ignition to have the light work.
If you need pictures from the ’61 manual to help you let me know.
To expand a little on Glen's reply...
The pulldown mechanism has some microswitches in it. As the motor pulls the trunk lid down, and reaches a certain pressure of tightness, one microswitch is activated, and that cuts off power to the motor. When you release the trunk to open it, two other microswitches are activated. One reverses the motor, so the latch rises bck up to the position where the trunk will latch again. When the latching mechanism reaches a set height, the original microswitch stops upward movement and resets for "pull-down" mode. The other microswitch (the one your question concerns), completes the circuit to the warning light on the dash. Any time the trunk is unlatched, and the mechanism is raised, this warning light shuld glow. None of it is tied into the ignition switch. that is, it should operate at all times even without the key. These microswitches are very delicate.
As gGen says, they connect near the pulldown motor itself. Mine is covered by the metal protection box, but the connectors are right there at the base of the trunk.
The 1961 shop manual does have a very good diagram and picture, and as Glen again says, it should be very similar to yours. I'll be haqppy to send pics or scans of my '61 system.
Glen and Jim,
Thank you both for the reply. I feel foolish for mentioning this now, but my '58 SDV does not have the power trunk. Did only the power trunks have the trunk tell tale feature? If that is the case, that explains why mine never worked!
I thought the trunk tell tale was standard on all models because the schematic has the wiring for it, but mentions the power trunk plug in as "optional".
If you can still send me the excerpt from the '61 manual, I would appreciate it. I'd like to learn about the mechanism although my car does not have it. No such thing as bad knowledge!
Thank you both for your responses. Please let me know if the trunk tell tale light is void for models without the power trunk. I'll feel foolish, but I will have my answer!
Thank you again,
Matt
CLC #21633
minnocenzi@wdpa.com
G'day Matt,
Don't feel foolish.
It is the foolish that don't ask questions that they would like answers for.
Bruce. >:D
If your car did not come with the pull down unit then the trunk light will not be connected.
It takes a welder to install the pull down unit in a car that did not come with it from the factory. It’s a totally different mounting bracket from the non pull down bracket.
I did install the release unit in both my ’61 Coupe Deville and my ’68 ELDO. I believe this was a dealer option to have only the release.
I hooked up the light to a switch similar to the door switch on the bracket for the lower latch. It grounds the green wire from the dash and lights the light. I think I had to also install a bulb in the socket too.
Looking at the wiring diagram it looks like the ’61 needs a power feed to the switch. I’m sure the ’68 only needs a ground to light the light.
Hi Glen and Bruce,
That answered my question - my trunk light is not hooked up from the factrory because I did not have the pull down option.
Thank you for the replies and addressing my concerns. If I ever decide to install the unit, at least I have some guidance. For now, I will keep it just as it is from the factory.
Thank you again Glen and Bruce!
Matt
CLC #21633
My latest project is getting the trunk tell tale indicator light to work. When I open the trunk and have the ignition on, the trunk light does not work. I checked the obvious - the bulb and socket were cleaned and tested. All of the wires are intact with no splits or cracks. The printed circuit board is also good.
According to the schematic in the shop manual, the trunk tell tale is the dark green wire and the manual just shows it going into the trunk harness.
My questions are:
1. Where does this dark green wire go after it plugs into the body harness? I see where it plugs in but I do not see it in the trunk.
2. What is the theory behind its operation? What goes on when the trunk opens to make this bulb go on?
[/quote]
Hi Matt,
I have a '58 Sedan deVille also without the power pull down, my tell tale on the dash also does not work, it is on the list of things to look at one day - although from other posts maybe it has never worked. A question I shall post on the '58 Owners list.
However, the light in the trunk should work without this tell tale glowing.
The '58s have a mercury switch that is part of the bracket that holds the bulb in the trunk.
A live wire comes from the body harness into the lid of the trunk (from memory this is dark green) and into the back of the bulb holder. Inside this bulb holder is the mercury switch which is sort of shaped like a glass fuse. When it is vertical (trunk lid closed) the mercury is all down one end of the glass tube and therefore does not make contact, when it is horizontal (trunk lid opened) the mercury runs to both ends and makes contact with the live wire and the base of the bulb, the bulb earths through the bulb holder and glows.
A little difficult to explain, but if you take the bulb holder out and remove the bulb the mercury switch is under the bulb.
Have a look it makes more sense to see what I'm trying to describe.
The mercury switch is insulated in a cardboard tube so it can't short out.
If yours is not working maybe this switch has lost it's mercury or the connection to the mercury switch is bad or ????
Cheers, Rob.
Rob McIntyre NZCLC 162
Christchurch
New Zealand
Hi Rob,
Thank you for the reply. My light works fine in the trunk, just the tell tale did not work. As I learned from some of the previous posts, the tell tale feature is inoperative for trunks without the power pull down feature. So, as you restore yours, don't go crazy to diagnose why yours isn't working considering you do not have the power pull down either!
Matt