Rant: Door light switch’s poor design

[RSBob]

I have no doubt replaced eight of these suckers on three cars, on one twice. They seem to last about 3 years before I have to wiggle the rubber cover to make contact. And we all know how fun they are to replace, especially the time the wire drops into the black abyss.

There must be something better or a way to rehab them so they don’t wear so quickly. Anybody have a better solution or a good fix when they start acting up?

[pete3799]

To my knowledge the switches in my car are the 38 year old ones they put in it at the factory.
In the 9 years i've owned it i cleaned them once and replaced the rubber. Work every time.

[universeman]

Try some Dexoit 5 on them before you replace them. All you're trying to do is get a ground to happen between the switch and frame. That should not require much contact.

[uwanna]

Originally Posted by universeman

Try some Dexoit 5 on them before you replace them. All you're trying to do is get a ground to happen between the switch and frame. That should not require much contact.

^^^ Do what he says! DeoxIT D5 is magic on electrical connections. I used it on my flakey door light switches and they haven't failed since.
I used to work in the high dollar commercial and home theater business,
and DeoxIT D5 is the standard of the industry for preventing and cleaning up oxidized and corroded electrical connections. Get some!
!

[porschenut]

Remove the rubber caps and leave them off. Over time they stiffen up and the spring isn't strong enough to overcome the tension from the stiff rubber, which prevents the switch from making contact. The rubber caps just aren't needed.

[uwanna]

Originally Posted by porschenut

Remove the rubber caps and leave them off. Over time they stiffen up and the spring isn't strong enough to overcome the tension from the stiff rubber, which prevents the switch from making contact. The rubber caps just aren't needed.

why not replace the 30yr+ old rubber caps with some new, cheap,
soft ones. I did as they get torn over time. Looks better IMO.

[ossiblue]

Yes, the main culprit is the rubber cap, not the switch. Replace the rubber or remove it altogether and the switches will likely work for a long, long time.

[RSBob]

Great info. Loose the caps and use DeoxIT. Thanks!

[88911coupe]

I have determined that the drivers side switch on my '88 does not work. If I turn off car and get out I can still work the windows with the door open and even after I close the door I can reach in and the windows still work. However, if open and close the PASSENGER door the windows STOP working, which as I understand is the correct function. I have noticed that if I open and close the driver door (not the passenger door) and come back a little later the window relay in the trunk is faintly warm. I assume this may be the cause of what appears to be battery drain? Also, not sure if this is relevant, but the relay NEXT to the window relay (window washer relay?) is ALSO very slightly warm. Is this another problem. I hate electrical issues.

[darrin]

Originally Posted by 88911coupe

I have determined that the drivers side switch on my '88 does not work. If I turn off car and get out I can still work the windows with the door open and even after I close the door I can reach in and the windows still work. However, if open and close the PASSENGER door the windows STOP working, which as I understand is the correct function. I have noticed that if I open and close the driver door (not the passenger door) and come back a little later the window relay in the trunk is faintly warm. I assume this may be the cause of what appears to be battery drain? Also, not sure if this is relevant, but the relay NEXT to the window relay (window washer relay?) is ALSO very slightly warm. Is this another problem. I hate electrical issues.

Buck -- congrats on tracking down your battery drain issue -- I had exactly the same situation with my '86 targa, replacing the pin switch resolved my problem and it's been fine for over 15 years now

You might want to try the DeoxIT trick first, and/or removing and cleaning the switch -- once out, it was pretty simple to see what caused my switch to stop working and clean back to new condition.

As for your washer relay, not sure but have a feeling it too will correct once you sort out your door switch/window relay issue.

[88911coupe]

I don't quite understand how having power to the relays would drain the battery? As long as the windows aren't being opened or closed how does it "use" battery power? I will definitely clean or replace them, just trying to understand the function.

[darrin]

Buck -- as I understand it, when the ignition's off and the door's open, the door switch activates/opens a relay that's normally closed. The relay's activated/opened by an electromagnet and the electromagnet draws current/creates heat. No big deal if the relay's only activated for a minute or 2 while door's open, but drain adds up if the "door never closes" because of the broken door switch. Make sense?

[88911coupe]

Ok that makes sense!

[88911coupe]

Quick question…now that I may have found my battery drain wanted to see if my battery is acting “normal”. I keep the car on a charger and have a fairly new battery. The car is rarely driven. Last night at 8 pm I took car off charger and tested battery which was 12.73, few minutes later it was 12.68. 6 am this morning it’s 12.53. Is that normal drop for 10 hours? Car has no alarm.

[GH85Carrera]

On my 85, it can sit for 6 weeks and still fire right up. Only in middle of winter will I bother to put it on the trickle charger.

[djpateman]

Originally Posted by 88911coupe

Last night at 8 pm I took car off charger and tested battery which was 12.73, few minutes later it was 12.68. 6 am this morning it’s 12.53. Is that normal drop for 10 hours?

A drop in battery voltage over a period of time is normal after the battery has been charged. This charging can be from driving the car and the alternator is doing the charging or from use of a battery charger.

The charging circuit is designed to have a higher voltage than the "normal" voltage of the battery itself. A 12V lead acid battery normally should have a resting & fully charged voltage near 12.8 volts. The charging system needs to be above this to force current into the battery to recharge it, so the typical charging voltage is near 13.8 to 14.2 volts. Once the charging voltage is removed you can observe the battery voltage to decline from the charging value to the resting value. There is what is called a surface charge on the plates of the battery; this is very similar to the charge on the plates of a capacitor. It is the surface charge dissipating that results in the battery voltage decline that you observe. The charge dissipates via the chemical reaction that is intrinsic to battery operation, and from any small current draw like the clock.

[Anglocanadian]

I'm toying with the idea of using small LED tap lights for interior, trunk and engine compartment !
Think of the weight saving : )