Author Topic: Defog switch (Read 2930 times)

sreta · « **on:** July 10, 2022, 01:47:06 PM »

Can I remove the plastic knob from the switch without breaking it? I know there used to be a thread about it, but don't remember how everything turned out.
Thanks

Wallington · « **Reply #1 on:** July 10, 2022, 09:53:30 PM »

It's likely the same as the other knobs on switches, wiper and heater controls etc, where it has a slight barb pattern on the edges. So while firm from being a tight fit and 40 years of sitting, it will also be tight, have to try and wiggle one way, then the other, progress is usually slow at first. You can now get reproduction switches, knobs already attached though. Are you trying to add a decal over the faded lettering?

sreta · « **Reply #2 on:** July 11, 2022, 11:52:48 AM »

Thanks Ben!
I got the new custom faceplate for the windshield wiper switch made by the local engravery shop. Now I want to do the same with two defog switches(second will be trunk remote switch). I broke both knobs when I disassembled the wiper switch, but didn't care about that cause I was planning to replace them anyway.

Warren Seale · « **Reply #3 on:** July 11, 2022, 01:38:23 PM »

Quote from: Wallington on July 10, 2022, 09:53:30 PM

It's likely the same as the other knobs on switches, wiper and heater controls etc, where it has a slight barb pattern on the edges. So while firm from being a tight fit and 40 years of sitting, it will also be tight, have to try and wiggle one way, then the other, progress is usually slow at first. You can now get reproduction switches, knobs already attached though. Are you trying to add a decal over the faded lettering?

How close is this reproduction to the OE? It looks like the lettering is silver rather than white and the green light is recessed in the faceplate rather than protruding from it. Does anyone have first hand experience with it? Maybe the lettering is not epoxy ink that degraded over time and flaked off.
https://www.thepartsplaceinc.com/product/1979/1979-pontiac-firebird-transam-rear-window-defogger-switch-gm-10002806-477877-527363-497978/102433

Wallington · « **Reply #4 on:** July 11, 2022, 10:07:15 PM »

Yeah, none here, just that they had started listing them as new products. Look decent to replace a faded, damaged or missing original but already minor differences as mentioned. Hopefully someone has one to report back.

« **Reply #4 on:** July 11, 2022, 10:07:15 PM »

firebirdparts · « **Reply #5 on:** July 14, 2022, 07:02:43 AM »

Quote from: Warren Seale on July 11, 2022, 01:38:23 PM

How close is this reproduction to the OE? It looks like the lettering is silver rather than white and the green light is recessed in the faceplate rather than protruding from it. Does anyone have first hand experience with it? Maybe the lettering is not epoxy ink that degraded over time and flaked off.
https://www.thepartsplaceinc.com/product/1979/1979-pontiac-firebird-transam-rear-window-defogger-switch-gm-10002806-477877-527363-497978/102433

That is interesting. That picture looks like an old one. It still says "patent pending" on it 50 years later. not likely. Reviews are good. two reviews from year 2020.

Wallington · « **Reply #6 on:** July 14, 2022, 07:29:50 AM »

There's a few stockists, same photos used. Lettering is white. On the defogger switch the lettering appears to be a raised casting with top brushed over in white. There's also a 70-77 dash door-lock switch reproduced, it has plain flat backing and pad-printed lettering onto face, not raised.

Apart from the change in text, light colour, they are still listed as suiting 70-81, as are the dash lock switches only used until 1977. With the defog switch 1977 was also the year they swapped the terminals around to allow them to be used on other GM, so not as simple as fitting all models as they claim. GM issued a notice at the time on how to modify, it was also in the service manuals, I think. The reproduction photos aren't clear with their arrangement.

roadking77 · « **Reply #7 on:** July 15, 2022, 05:48:16 AM »

Ive never bought from the parts place but may get a couple of these. A lock switch would be nice as well. However the switch in the pic looks either used or not processed very well in the manufacturing. Terminals look a bit 'burnt' and the housing is very dirty. I try not to get picky but for $70 and expecting a new part, I want it to look new.

another10th · « **Reply #8 on:** July 15, 2022, 07:42:05 PM »

I have one of those rear defog switches from the parts place. The lettering is not as thick (?) as the original. There is also an external resister that is not present on the original. As noted, the pilot light is recessed. But that is not noticeable at a casual glance. I had to do a bit of filing on the back edges of the switch to make it fit in my original mounting bracket. I suppose it works, but my car doesn't sit outside so a functional defogger isn't really necessary. (I think only one or two elements in my window are intact.) One peculiar thing I noticed is that the pilot light on the switch flashes when I turn the car off. (With the defogger switch turned off.) I'll leave that for the experts to debate why that might be. Overall it's not bad, but it doesn't look as good as the one Eckler's sells for the Corvette. (Which looks exactly like the Firebird switch from the front.) Unfortunately, the Corvette's switch has the mounting ears in a different location.

Wallington · « **Reply #9 on:** July 15, 2022, 08:18:35 PM »

Would you be able to redrill new mounting holes? I've had to do that with half of mine, actually, all of mine, but several filed or trimmed to fit opposite side to designed. As long as the plug matches, they seem to have left that for the purchaser to discover later.

Back to topic...Sreta, any luck removing knob? I've done it on heater controls but not defogger switch.

another10th · « **Reply #10 on:** July 15, 2022, 08:32:02 PM »

Quote from: Wallington on July 15, 2022, 08:18:35 PM

Would you be able to redrill new mounting holes? I've had to do that with half of mine, actually, all of mine, but several filed or trimmed to fit opposite side to designed. As long as the plug matches, they seem to have left that for the purchaser to discover later.

Back to topic...Sreta, any luck removing knob? I've done it on heater controls but not defogger switch.

No, the tabs with the mounting holes are located differently.

Wallington · « **Reply #11 on:** July 15, 2022, 09:20:52 PM »

Is this the one? I though they may be from the same supplier, reusing common parts but this one looks different, at least to the stock photos used in the other. The terminals are fresh and shiny and the green light is not recessed. At least with the Firebird repro that features the INDAK electrical section, appears it could use original GM supplier and US-based for the repro, which isn't common these days. It would be a good unit for comparison in the NOS vs repro thread, or vs used in any case.

My car doesn't have the rear window grid and no real reason to add one on what would essentially be a sunny day driver, but still interested.

https://corvettecorner.com.au/shop/c3/wiring-switches-c3-68-82/switches-lighting-wipers/78-80e-rear-window-defroster-switch-9571/

sreta · « **Reply #12 on:** July 16, 2022, 04:19:33 AM »

Yes, I did it

With this home made tool, it was a two seconds job.

Wallington · « **Reply #13 on:** July 16, 2022, 05:27:57 AM »

Good stuff. Couldn't stop at one, went and did a second that couldn't outrun you!

Warren Seale · « **Reply #14 on:** July 17, 2022, 10:09:39 AM »

Quote from: another10th on July 15, 2022, 08:32:02 PM

Quote from: Wallington on July 15, 2022, 08:18:35 PM
Would you be able to redrill new mounting holes? I've had to do that with half of mine, actually, all of mine, but several filed or trimmed to fit opposite side to designed. As long as the plug matches, they seem to have left that for the purchaser to discover later.

Back to topic...Sreta, any luck removing knob? I've done it on heater controls but not defogger switch.
No, the tabs with the mounting holes are located differently.

The tabs look like they are in the same location when comparing the photos. Is it that the holes are located differently in the tabs?

« **Reply #14 on:** July 17, 2022, 10:09:39 AM »

another10th · « **Reply #15 on:** July 17, 2022, 05:07:06 PM »

Regarding the mounting tabs....
They do look similar in the catalog. But as you can see in the photos, the Corvette switch has them much farther back relative to the face of the switch. Also, the mounting ears on the Corvette switch has gussets (for additional strength, I guess.) I suppose one could cut them off of the Corvette switch and after eliminating the gussets, glue them into position to use in a Firebird. I don't know how much strength they would have. Also, whereas the terminals on the back look the same, they are actually inverted on the Corvette switch. Depending on the internal circuitry, that might not make a difference. The lettering on the repop Corvette switch appears to be "thicker" than the Firebird switch (was). The Firebird repop switch available from The Parts Place has lettering that is "thinner" than I remember the original being. (I can go out to the garage and photograph that one if someone needs to see it, as it is already installed in my car. (That's why I used an old Firebird switch for these pictures!)

Wallington · « **Reply #16 on:** July 17, 2022, 09:20:11 PM »

Good pics. Looks like the Corvette switch, if it remained the same over the years, may have used the same terminal arrangement as the 70-77 F switches. Pic shows the 77-79 arrangement as 80-81 had an extra terminal for relay timer. These switches can generally be identified before that point as they had the new rear demister standard icon light next to it.

1977 Firebird defogger heated backlight switch terminal update by Aus78Formula, on Flickr

sreta · « **Reply #17 on:** July 26, 2022, 03:34:13 PM »

New faceplates

Wallington · « **Reply #18 on:** July 27, 2022, 04:06:58 AM »

Nice work, you'll need to tell us about the trunk switch now. Custom using another demister switch for trunk popper?

sreta · « **Reply #19 on:** July 28, 2022, 09:01:57 AM »

Yes, the other one will be for the trunk popper. I hope that will be easy to make. The power goes to the alone terminal on the right and continues to the middle terminal on the left(above photo).

Wallington · « **Reply #20 on:** August 14, 2024, 09:51:14 AM »

Years ago someone asked me for a better scan of that bulletin update, Warren?? Either way, I only just came across it again and have scanned larger. It's still 10x larger than what it comes up as but here's a sample.

1977 Firebird rear demister switch change notice (1) by Ben, on Flickr

1977 Firebird rear demister switch change notice (2) by Ben, on Flickr

« **Reply #20 on:** August 14, 2024, 09:51:14 AM »

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Author Topic: Defog switch (Read 2930 times)