4 way hazard flashers

Hi, I recently discovered that my hazerd flashers aren't operating. Push in on the steering column switch and zero. After much work all other lights now seem to work correctly including turn signals. I've gotten a new 552 flasher unit which I believe is the correct one but I'm unsure where it should go. There is a gray, round plug marked flasher on the upper left side of the fuse box, is this it? Should there be one flasher unit for turn signals and another one for hazard flashers? There's also a grey square box type plug too, not sure of it's purpose. Any comments/insight would be great !

Sure your brake lites work? Don't know about 75 but on 79 the brake lite fuse is also the hazard warning lites fuse.Do the hazard lites come on but not flash? Mike

Also, at least for 79 there are 2 flashers in the fuse panel, one is for hazard. Don't know about 75. Mike

Yes there are two flashers. One for the turn signals, one for the flashers. First, do all of the turn signals and brake lights work? The front and rear turn signals, and brake lights are the same bulbs and wires from the turn signal switch. The turn signal switch separates all 4 corners of the car. Left and right, as well as front and back. You don't want brake lights in the front.
The brake light switch feeds the turn signal switch. The flashers just connect all four corners to the 4 way flasher at the same time. Also part of the turn signal switch.

If the turn signals work front and back, the wires and bulbs are good, and so is the fuse and t/s flasher.
If the brake lights work, the brake switch and that fuse is good.
If the 4 way flashers don't work at this point, the flasher unit may be bad. Either that or you have a bad connection from the fuse to the flasher, or to the t/s switch. If everything else is good, the t/s switch is bad.

The 552 flasher does not require a fixed load to operate, so it is used in the 4 way flasher. It can be used in the turn signals.
Turn signal flashers are designed for a given number of bulbs. So if one bulb burns out, the flasher won't flash and warns the driver of a problem. It will also flash too fast if an extra bulb is added, such as connecting a trailer. The 552 will flash if only one bulb works. It will also flash the same if more bulbs are added. It doesn't care what the load is. They are often used in the turn signals when a trailer hitch is added. It is used as 4 way so they work even if one bulb is out.

Ken Styer

The flasher that plugs into your fuse panel is for the 4-ways. The flasher for the directional signal is located behind the passenger side dash panel near the vent duct.

Hey guys, thanks for all of the excellent advise ! This forum is really great ! I hope someday I'll have some knowledge to give back to someone else. My car looks a lot like yours Brent except it's a 75 and strangely enough the orig dealer invoice says it was sold (still has) with a red conv. top even though only options were supposedly black or white. Anyway, thanks again to all !