Warning Buzzer for Low Coolant/Low Oil Pressure - PeachParts Mercedes-Benz Forum

777funk · #1 06-14-2008, 05:30 PM

I've been working today for a couple hours in the instrument cluster trying to figure out a way to connect a buzzer to warn that the coolant is low/and/or Oil Pressure is low.

Here's where I started, let me know if my logic is wrong:

1. The light on the Instrument Cluster lights up if the coolant reservoir ever goes low (level sensor) as does the oil. I'm not sure what the oil light does on the cluster. Any ideas what that is sensing?

2. I plan to use the 12V signal on these lights to also run an annoying sounding buzzer to let me know to TURN THE ENGINE OFF NOW.

In order to isolate I was going to use diodes, not that this part matters much but just for explanation's sake.

Here's where I'm confused as heck... I figured the lights would have two wires and I could just use the hots. But... the power to the lights I care about (oil pressure, and coolant level) come off of the 15 wire socket. Anyone have any idea which wires on the harness are these?

Lastly, Anyone got a better/easier idea of how to accomplish this?

with the 603 I think it'd be especially nice (more so than with a 61x engine) to have a buzzer to warn if it is going to overheat (low coolant).

bustedbenz · #2 06-14-2008, 05:52 PM

Quote:

Originally Posted by 777funk

1. The light on the Instrument Cluster lights up if the coolant reservoir ever goes low (level sensor) as does the oil. I'm not sure what the oil light does on the cluster. Any ideas what that is sensing?

Oil light senses low oil level. One or two quarts down from recommended level and this lights up. Sensor is in the side of the oil pan.

bustedbenz · #3 06-14-2008, 05:53 PM

Quote:

Originally Posted by 777funk

with the 603 I think it'd be especially nice (more so than with a 61x engine) to have a buzzer to warn if it is going to overheat (low coolant).

The dash light signal for the coolant tank is useless for this function. Not sure if you were proposing to use it or not - it would certainly be a good warning if the coolant were low leading to overheat - but supposing the serp. belt breaks... you'll overheat and never lose a drop of fluid.

Diesel911 · #4 06-14-2008, 06:09 PM

Here are some threads concerning the low oil pressure alarm.
http://www.peachparts.com/shopforum/search.php?searchid=2638752

Jeremy5848 · #5 06-14-2008, 06:50 PM

Neither low coolant nor low oil level are immediate "threat to life" problems. Low oil pressure and high coolant temperature are much more serious and deserving of an "annoying buzzer." Both gauges are electrical on your 603 engine; some kind of transistorized alarm circuit would be nice.

777funk · #6 06-14-2008, 07:05 PM

Quote:

Originally Posted by bustedbenz

The dash light signal for the coolant tank is useless for this function. Not sure if you were proposing to use it or not - it would certainly be a good warning if the coolant were low leading to overheat - but supposing the serp. belt breaks... you'll overheat and never lose a drop of fluid.

Very true,
I suppose maybe a battery to buzzer would be good as well. That way when the alt. stops turning it'll sound the alarm letting you know something's wrong.

With cars this old, it's nice to have something to help preserve them as long as possible. Things are bound to break. Nice to know when it's happening instead of letting smoke, steam, and cracked heads let us know. Also I guess in the case of oil pressure dropping off the timing chain snapping and cam breaking wouldn't be as nice of a sound as an annoying warning buzzer.