The Stovebolt Site Forums The Shop Area The Electrical Bay FLASH! Bombshell turn signal discovery

Important meaningless info! I have discovered a disturbing GM Factory Fuse Panel Wiring Mistake. (FFPWM). This mistake has never been noticed in over 60 years. I reveal this copy written, intellectual secret here on Stovebolt.com. I can be contacted by PM/Email for interviews, by Nobel prize committees, magazines, job offers, letters of congratulations and so on. It is with great humility and modesty that I amazingly have become a idolized mentor guru who will serve my unknowing public.

Part 1: The operation:
Since GM started offering factory turn signals and in-cab fuse panels in about 1960. There was a two prong flasher receptacle. The flashers are of the "thermal" 552 type. We have always known that on those flashers that "X" prong is for ignition switched battery power. We also know that "L" is for "Load". The thermal flasher has two circuits inside, one small, high resitance wire coiled around a bimetal strip. The other circuit is the primary circuit, basically the strip inself flexing, touching a contact which passes full voltage to bulbs. These flashers could be called a normally open momentary switch or a relay, kind of. When the turn signal switch lever is moved, the switch connects voltage to either left or right bulbs. Voltage comes in the "X" flasher terminal thru the small coil circuit, out the "L" and into the turn signal switch. Voltage/current gets distributed by the turn signal switch to the proper bulbs, thru bulb and into ground. The low amperage coil-wrapped strip inside flasher gets hot, without lighting bulbs, and flexes to touch the primary contact. Then voltage takes the "big" primary path to light bulbs. Strip current goes to zero and strip cools. Strip flexes away from primary contact, gets some current and back and forth every ~ second.

Part 2: The "mistake":
At the rear (or inside) of a GM fuse panel, are the factory harness wires in and out of the panel. On the Chevy and GMC wiring diagrams that I have studied, 1960 to around 1973, they used a brown or red wire from battery switched power to a flasher socket and a purple/Vio wire, for the load, to the other socket The purple goes to the turn signal switch. There is only one way to install a two prong thermal flasher into the sockets. GM has the RED or BRN power wire wired to the "L" prong socket and the Purple or VIO load wire wired to the "X" socket!!!!! Holy Cow, how come nobody noticed? "How can millions of flashers work if it's so "wrong" Bartamos? or whatever your name is?"....because the heater circuit can be wired either way and heats the strip.... Then when primary contact is "thrown", full voltage goes toward the grounded bulb.... and The flasher never knows the difference. If GM ever noticed the error, seems they would have changed the diagram at some time.
I post this for those who are installing an aftermarket T/S switch with hang down flasher, for someone rewiring their factory fuse panel or buying a fuse panel for DIY harness build. It may help to avoid confusion if following a factory wiring diagram or copying and old fuse panel. No worry about harness kits, they have it "correct". With aftermarket column turn signal switches, follow direstions.
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WOW, what an amazing discovery! I have wondered which direction that the electrons flowed through my various vehicles over the past few decades,, err maybe more than a few.

The way I figure it, GM owes you a big check.

I would probably just assume it’s already in the mail and buy yourself something real nice in the meantime.

Next topic - who would you like to play the role of “you” in the movie? And who should write the screenplay?

Electrons (current) flows negative to positive. Current flows positive to negative. Most everything we use, and work on, is considered positive to negative. The word "ground" is only really used in DC.
After electrons were discovered it was too late to change to a more technical negative to positive narrative,...and it makes no difference to any DC circuits we live with as long as we know when something is wired as DC positive ground.

We can get into a tizzy discussing flow. Some folks confuse AC with DC flow in that discussion. AC has no flow direction, it reverses back and forth. As the name implies, "Alternating Current". Sine wave. AC "ground" does not carry the same meaning sometimes. It's circuits are described in terms of "HOT", "Common", "Neutral" and earth ground. Many folks get electrocuted I think because they see that neutral and the bare copper ground go to the same place and the nuetral is just like ground. NO.....the white and/or the black wire can kill you. I really hate discussing AC wiring for fear I will mislead, so don't pay ANY attention to my AC thoughts. I AM NOT UP ON AC AT ALL.

JW: I did put a down payment on an Island. I did get a call from GM but it was about a "late" truck payment. Minor issue.

bartamos I felt like things really went south when the 3 prong flasher came on the scene,muddied up the water. Then I became a truck inspecter in the intelligent state of Il.so everyone dumped their turn signal troubles in my lap. Worst was hog lot trucks,never fear Millard Pigg (his real name) said oh we just drop a plug wire on the ground,let it idle pigs wont go near it. Carefully reach in shut key off by leather cover(was ferd on left) put wire back on ...go.

In a company that big, it’s hard for the left hand to know that the right is doing. “Accounts Receivable” and “Big Rewards” departments just didn’t communicate with one another. Probably more than one bartamos in their systems. Dots never got connected.

Some middle managers will probably get a scolding. But from your end, I’d just ignore the late payment notice.

The notice was to shut me up....they know the horse manure business is slow becase of Covid and that supply chain thing.
Making flashers work backwards for years is no laughing matter. No one knows what illness that could cause years from now.

Backwards flashers are known to cause cancer in California.

This discussion is getting a bit off track guys. Might need to be moved to the 'Spoon.

KL, it's fine for now...

OK. Back on track everybody. Stick to flasher. My fault. Kevin is right, the schtick is for the spoon. Thanks Rusty.

Roger, Rusty
Good info on flashers that definitely belongs here in the Electrical Bay.

Gosh. On request, I'm gonna lock this thread until Rusty or Kevin can sort it out.

Maybe it's just too tempting. But ... the Mod(s) can sort it out, move funny business to Spoon and keep the actual electrical stuff in here.

Temp lock ....

Thank You Ms. Peggy. I've been mulling this one over for a couple daze now.

Since we have gotten the humurus out of the way, lets get back to business.

Mr. Bartamos, if you want this thread to continue to play out, I'll move it to the "Spoon.

R/S
Rusty Rod