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Home » Public Forums » GMCnet » [GMCnet] Help! What Could Cause Unidentified LOUD Alarm?
[GMCnet] Help! What Could Cause Unidentified LOUD Alarm? [message #350058] Tue, 12 November 2019 15:48 Go to previous message
Vern Crawford is currently offline  Vern Crawford   United States
Messages: 81
Registered: August 2016
Karma:
Member
There is a new, but very annoying problem with our 1977 Palm Beach. Lenore
refuses to go anywhere in our coach until I can somehow kill the irritating
culprit!

The loud buzzing alarm does not come on when the ignition is turned to the
Accessory position.
However, 18 to 40 seconds following turning the ignition switch clockwise
to engage the engine on position the buzzing alarm starts piercing our
ears. It does not matter if the starter is used to start the engine, or if
it is simply left in the ignition "on" position, the loud buzzing alarm
kicks in after the delay of 18 to 40 seconds, and does not stop until the
ignition switch is rotated back to the "off" position.

The time delay of of 18 to 40 seconds seems to vary based on a capacitor or
other electronic device loading up before actuating the buzzer. When first
turning the ignition switch to the on position it will take 40 seconds
before activating the buzzer. If the switch is turned off, which is the
only way to silence the loud buzz, then the switch immediately turned back
on the delay before the buzzing is only about 18 seconds or so. If then
waiting a half-minute or so before turning the ignition on and the buzzer
kicks in at around 30 seconds; wait a whole minute or longer and the darn
buzzer delays for the original 40 seconds. Over the last several hundred
miles of travel, and several hundred tries to diagnose the culprit this
timing variation has been consistent.

Our's is a stock tortoise shell instrument panel, with standard round
analog gauges, with a small blue indicator light for bright headlights
centered on the steering column and above the speedometer and tachometer,
with green turn signal indicators to the upper left and right of those two
gauges. To the bottom right of the tachometer is a small red trouble
indicator (idiot light).

All TellTale lights and gauges behave normally. When the ignition is
first turned on the "generator" light comes on, along with a totally
different higher pitched and equally loud alarm comes on, and remains on
until the engine is either started or the ignition is turned back to the
off position. The troublesome loud buzzing is in addition to the normal
higher pitched alarm mentioned in the preceding sentence.

The actual location of the buzzer itself is somewhere out of reach and on
the far side of the hard black plastic portion of the HVAC venting leading
to the drivers right knee vent, and continuing to the drivers left knee
vent via flexible tubing.

I have removed the plastic horizontal access panel below the steering
column, and taken out all of the screws that appear to be holding the upper
section(s) of the dash and instrument pane. I'm reluctant to completely
tear up the dash in the pursuit of finding and destroying the aggravating
buzzer with a sledge hammer. All of the exposed under dash wiring appears
to be in original mint condition, and I don't want to just use brute force
to bull out the buzzer itself. I much prefer to find what is triggering
this awful buzzing sound.

Over the past three years and our 30,000+ miles of driving the coach there
have been a few occasions when a low fuel condition has also activated a
similar sounding alarm, along with turning on a yellow warning light. But
switching the tank position to auxiliary (and stopping at the next
opportunity to put in fuel) has extinguished both the yellow light and
buzzer.

Also eliminated is the low engine coolant sender. When the connection to
the radiator is interrupted then the normal high pitched alarm is
activated, along the little red dash idiot light.

Hopefully someone else in our collective brain trust has run across this
problem and its solution! I promised to visit our granddaughter next week,
and I'd like to bring Lenore along with me in the passenger seat.

Thanks for any ideas,
Vern
--
Vern Crawford (and Lenore Langsdorf)
155 JJ Lane
Center Point, TX 78010
(618) 203-8296 Vern's cell
(830) 928-5550 Lenore's cell
VernCrawford@GMail.Com
LenoreLangsdorf@GMail.Com
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