A friend of mine had a trouble with headlamps. He would like that I'm looking into the lamp switch to see if something is bad. Did somebody opened such a 1969-1975 switch or is that mission impossible? I don't have the switch yet, I should get it in the next few days.
Thanks for your comments!
I never tried to open one up, but they were used in millions of GM vehicles so are readily available new (probably made cheaply overseas). There are some minor differences with the pinouts over the years.
Don't be too fast to condemn the headlight switch, unless it's known to be faulty. The dimmer switch from the mid 60's to the mid 90's were famous to make poor connections. Especially the plug connection to the dimmer switch. They get hot, damp and dirty hanging out under the carpet.
Thanks for the answers! However, you missed the point: can the switch be opened or not?
Just for your info: the owner replaced the foot switch some time ago and found recently some badly "repaired" wires emerging from the switch. No need to buy another switch if the one he has is good, but how to prove it?
I'm reasonably sure they can be taken apart, just carefully. The last one I did was for a '59. It was a simple circuit board inside with old crusty grease and a top circuit board, (using that for the lack of a better term) that slid over the lower one to make the needed connection path.
The wiring connectors is what burns them out. The connectors get dusty, loose and then start getting hot, making the connection worse, then none at all. Much of that resistance starts at the headlight bulbs themselves because they are the first item on the path out in the weather.
Clean up all the connections first with contact cleaner, a fine wire brush and then when reinstalling, use dielectric grease on them. If you do have to condemn the switch, remove it, take it apart and clean it, again putting it back together with fresh grease and be sure the connectors going to the switch are clean and tight.
Yes, I've done it. But like others have said, it wasn't the cause of my issues.
A good cleaning of the grounding points at the headlights and the foot switch resolved my issue.
After opening it and cleaning it and having it not work, I bought a new one for about $20. It worked exactly the same as the restored one.
Indeed, the light switch is rather easy to open by bending the stell tabs at both sides. Contrary to earlier switches, no spring is flying as they stay inside a "chariot".
I cleaned the bi-metal's contacts, assembled back and it's ready to be installed back into the car.
New repro switches are available now for a tad over $ 25.00.
DSC03499.jpgDSC03501.jpg
That one got a little warm. Look at the contact points bar. Very discolored. High resistance from bad or weak grounds.
It's what I found too! There was a previous "repair" at the main wire to the dimmer switch creating the mess.