Because of some ongoing dash work I've left the trim pieces off including the headlight ****. I noticed when I touched the metal pull switch one night that it was kind of hot. After letting it cool off by going into the store, when I got home it was still pretty warm. I'm pretty sure there's some corrosion in there somewhere, but would it be better to clean it somehow or just replace it? This is on a 1978 98.

 

There is a resistor built into it for the dash lights. That will naturally generate heat if you have them dim.

 

This is normal.

 

But I dont have them dim, I've got them cranked up to full intensity. If you're saying it's normal under that circumstance too then ok, I'll believe you. Just thought I would ask, better safe than sorry.

 

Any resistor will impede/resist electron flow - same as stating electrical voltage will be reduced/impeded. A resistor is installed to "resist" electron flow causing the voltage to drop. The heat you feel is normal (as stated). Resistors can be of a single ohm or a w/in a range of ohms. This reduced voltage (resistance) via the resistor is converted to heat - less heat (resistance) at full intensity, more heat (resistance) when fully dimmed. In both cases any resistor impedes/reduces electron flow which decreases voltage - this decrease in voltage is converted to heat and is normal as stated.

 

I figured it was a good idea to go in and clean the switch connectors. Im glad I did, there was a fair amount of corrosion on one of the leads. I'd like to post pics but right now the site won't let me.

 

Warmly suggest that you reduce heat by removing corrosion/dirt/etc. This is a multi step process to me. First up, recognize that the light switch and especially high beams are high amperage, high heat connections. GM, or at least Olds didn’t really design for deterioration in way that would work for 50 years or more. So when you disassemble the components, you’ll find melted insulation, heat scoring, melted plastic shells, and so on. These conditions are normal and not a problem, until they short. Then you have at least mild fire danger.

If you’re restoring the light switch and related plastic/brass connector, the first move is pop the brass female contacts out of the plastic shell on the wiring harness side. Then use a dremel to clean off all the corrosion leaving a nice clean brass connector. It doesn’t need to be shiny, just free of corrosion. Shiny is good too, but not a goal.

On the switch side, use fine sandpaper (300-800 grit) to sand off corrosion from the spade terminals so that, again, you minimize heat and have a strong electrical connection to the female (wiring harness) side. You can also use Deoxit 5 to clean terminals if you prefer. I usually clean heavy crap off both terminals with a dremel wheel, then Dexoit for max conductivity and minimal heat.

You may want to get a new plastic shell because your old one is melted from previous troubles. The system is called “Packard 56” and you shoudl be able to buy replacment male terminals, female terminals and plastic shells to restore your system to factory specifications. Personally, I have a tackle box full of terminals that work with various wire gauges and tons of plastic shells that fit male, female and multi-connector terminals. But I’m probably a wiring nerd with that tackle box. I’m a big believer in having parts on hand to fix whatever’s broke on Sunday at 7:40 p.m. when all the stores are closed…

The last thing to suggest is dipping the resistance wire / heat sink in evaporust to remove years of corrosion chemically. I’m not sure this will work. If you don’t like that idea, go at the resistance coil wilt a dremel wire wheel to get the dust off as best you can. More or less, dust = heat. Minimize dust and corrosion wherever you can for best longevity.

Years ago before I went through the light switch on my 98 convertible, the switch heat sink and related components got so hot the high beams would just cut out while driving. It took me a couple of decades to figure out the fixes I mention above. I hope this helps you solve your problem in less time and with less effort than it took me.

Cheers
Chris

 

The middle connector was the problem, the rest were surprisingly clean.

Yes indeed, I went with a wire brush and CRC electrical contact cleaner.

 

Nice you have been able to identify the apparent issue - looks like both connectors need to be replaced - that's a sizable crack which appears deeper than a simple surface crack. Good detective work.

 

I actually didn't notice that crack at all, thanks for pointing it out. Is that just from heat warpage and is just cleaning the lead sufficient? Is that crack going to be a problem going forward?

 

I don't know if the crack is the result of the heat (likely) or a possible manufacturing 'weak-spot' defect (possibly). It is likely the crack is going to be a problem moving forward - replace it.

 

Ok. I see RockAuto has a "GM Genuine" replacement that looks to be the right one, I'll get that ordered up. Out of curiosity, what could go wrong with the crack if the switch isn't changed out?

 

The crack (opening) represents a loss of integrity w/in the connector. It's possible corrosion/oxidation has entered the connector via the crack (opening). It's possible the crack (opening) provides an increased opportunity to develop corrosion w/in the connector on one or several of the underlying metal pins. Heat increases the rate of chemical Rxns. If there currently exists corrosion/oxidation on a single pin or multiple metal pins additional corrosion/oxidation will continue unabated. This would likely increase the resistance of the connectior pin(s) resulting in more heat facilitating a continued loss of integrity until (possibly) the connector melts as the resistance (and heat) increases. I don't know the exact answer other than to suggest the integrity of the connector appears to have been compromised & warrants replacement.

 

Maybe try these.

https://ipatools.com/product/8040-di...inal-cleaners/