mtndew

So I'm driving down the street and all of a sudden my car starts making a really LOUD high pitch noise. It's some kind of warning buzzer. And after a few minutes it's goes from a steady beeeeeeeeeeeeeep to pulsing beep beep beep.. i shut the car off and let it sit for a few and it goes away for a while then comes back after a few minutes off driving again. The add Coolant light is on but it's full. Other than that there's no warning lights or anything. What's going on here ? I don't like that noise and it hurts my ears!

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LizardFC

iTrader: (1)

That's the low coolant buzzer. There my be air bubbles in your radiator due to a small leak, or the sensor itself/wire to the sensor could be bad. It's that little guy on top of the radiator with the single wire going to it.

mtndew

Hmm, what if there's no sensor and the wires just hanging? I've got an aftermarket race radiator in there with no spot for a sensor, how can i get rid of the light/noise? Or at least just the noise

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ray green

iTrader: (14)

It sounds like it's the Oscillator. That screeching sound is very diagnostic. Has it been raining out there in WA lately?

The definitive diagnosis and repair is simple. Find the Oscillator up by the left headlight, attached to the chassis right in front of the battery.

Unplug it. If the noise goes away, it's the Oscillator. To fix it, leave it unplugged.

When the rain stops, try plugging it back in. Usually this does the trick.

DreamInRotary

iTrader: (49)

I've had a similar issue. Annoying as all hell when driving. Just follow Ray's advice and all will be well.

stevensimon

iTrader: (11)

thats like putting electrical tape over warning lights.

ray green

iTrader: (14)

Actually not. The oscillator system is a redundant system, so if your temperature sensors and coolant level sensors are functional, it's not needed (especially if you're in the habit of routinely checking your fluid levels, as you should with any 25-30 year old car).

If your oscillator is screeching, it's a good idea to immediately unplug it to avoid permanent damage to your ear drums. This also should serve as a reminder to check your fluid levels just to be sure it's a false alarm.

That said, ideally it's better to have it working if possible. That's why plugging it back in after giving the connections a few days to dry out usually fixes the problem.

Until you get another spat of cold wet weather.

mtndew

Thanks for the info, I'm gonna try that out in a few minutes, but as far as plugging it back in, they call Seattle rain city for a reason. May have to look into a way to water proof it.
For the add Coolant light, i know it's a good idea to keep the system working but like i said before there's no spot in my radiator for the sensor and i check my fluids pretty much daily so I'm not too worried about deleting it. But how would i do it with just one wire? Ground it out?

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DivinDriver

iTrader: (15)

Grounding it should work; it's just a dipping sensor that grounds through the anti-freeze. Keep an eye on the current though, to play it safe. Might need a resistor in line.

ray green

iTrader: (14)

He may have two separate problems. It sounds like the check cooling light has always been on and just a minor annoyance because of his aftermarket radiator.

The Oscillator Screech is something else. It comes on suddenly, at the worst possible time, and sounds like an amplified radio warning for a nuclear attack.

After a minute or two, when the Oscillator starts to get hot from putting out all that screeching sound, it fades to a dieing rabbit sound, kind of a gasping eerch, eerch, eerch.

.

Qingdao

iTrader: (3)

I unpluged my warning buzzer

but every time I drive the 7 my Dakota has at least a half tank of fuel and a towbar in it with keys dangling in the shop :P

mtndew

Ray, perfect description! I couldn't have said it better. But what is the oscillator? And what's it for? And why the hell is it warning me of the incoming nuclear attack lol!?

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ray green

iTrader: (14)

The oscillator oscillates, that's all I know. It's one of the more mysterious components on an FB.

It sits up in front of the battery, behind the driver's side headlight, attached to the front chassis panel by a small pronged bracket. There's an electrical socket connected to it, just slip this off while holding the oscillator so you don't bend the bracket - sometimes that connection gets pretty tight after all those years.

If the noise goes away, it was the oscillator. If anything else also happens to your car (overheating, small nuclear explosions, that kind of stuff) let us know.

That might help us understand why FB's have an oscillator.