Proper operation of slow down lights

Here's something I haven't been able to find the answer to. When I turn they key to the run position (not started yet), are the slow down lights supposed to illuminate, then go out like the seat belt warning and brake failure lights? I'm curious to know whether these lights on my car work, or if they've been disabled.

When I was poking around under dash to replace the brake light switch, I saw something that had a wire disconnected. I know now that this is the warning buzzer/ringer and I understand now why it was disconnected -- it's annoying as hell! This makes me wonder if there are other annoying things that have been disconnected.

This is on a carb '78 GTS.

 

Yes -- see page 25 in your 150/78 OM. The operation of items 84 & 85 (the overtemp warning lights) is described.

 

Yes, I reconnected mine, not remembering why I disconnected in the first place in 1984.

FWIW, you don't want to try and disconnect it while it is buzzing, it seems to put out a high voltage, low amperage current, similar to those metal foil covered joke books with the battery in them when you touch teh case and wire at the same time. Or maybe the buzz frequency excited the nerves in my arm up the elbow in a similar fashion, but I let go of the wire connector and box real quick.

Doug

 

Ah, I see. Yet again, the OM has the answer. I was looking in the "Running instructions" section and didn't carefully read the description of the lights themselves. Guess I'll start chasing this one down as well.

 

Ha ha -- maybe that's the buzzer's self-defense mechanism to keep from getting disabled I don't necessary mind warning devices, as long as they're not too annoying. The one in my VW is a musical chime with different notes. The one in the 308 sounds like an old school doorbell buzzer. Annoying!

 

Just now circling back to this -- how should I go about troubleshooting this problem? Seem to me the slow-down light are pretty important in heading off a major problem. I don't know if mine have been disabled or it's something else. I opened the panel in the passenger footwell (after pulling out an old Blaupunkt stereo amp that was jammed in there) and can see the slow down ECUs, but I don't know how to troubleshoot from here. I do see that some of the insulation has disintegrated from the ends of the wires (the ones with the spade connectors), but nothing else looks obviously out of the ordinary.

It's my understanding that the thermocouples in the cats generate voltage (on the order of mV) to the ECU, which in turn will light the warning lamp. Is there a way to simulate an overheating situation to get the lights to come on? How do you remove the light from the dash? Perhaps it's as simple as bad or missing bulbs.

 

After staring at the wiring diagram and more staring at the ECUs, I found the problem. Some joker had removed the bulbs! Why would anyone want to disable this system?

 

Classic trick by worthless (so-called) mechanics to sell a car with a warning light coming on. Sad really.

 

You give me an idea for when I go to sell my car. Wire the slow-down lights to the starter position of the ignition switch. (My car came with test pipes). That way they will illuminate properly at startup and never cause anxiety while driving.

 

I like the way you think. Neither of my cars have cats therefore, no warning lights. But if they did...