-----Original = Message-----
From: John Rodgers <inua@HIWAAY.NET>
To: = vanagon@GERRY.VANAGON.COM = <vanagon@GERRY.VANAGON.COM&g= t;
Date: Monday, April 17, 2000 6:44 PM
Subject: Re: Flashing = dash LED

Andrew, you are going to get a lot of = response on this one.

The flashing light is the "low coolant level warning = light".

You have two water tanks in the coolant system. They are in the = engine compartment. There is the coolant expansion tank, and the coolant = overflow tank. The expansion tank is an active part of the system and when = the engine is running coolant circulates through expansion tank. In the top of = the tank is a sensor with two electrodes or prongs that stick down into the = coolant. As long ast the coolant is above the tips of the electrodes, a tiny = current can pass between them, keeping the LED light on the dash in the "off" mode. If the coolant gets low, the circuit is = broken, and the light comes on blinking, telling you to add or at least check = the coolant level.

As a self test, the light comes on at engine start, will blink = for a time and then go out. That is proper operation of the light. On occasion = the LED will come on during driving. If the coolant is very hot, the = light  comes on, and it will come on if the coolant/water mix is not 50/50. = And it will come on if there happens to be a little trash caught on one of = the electrodes.

The coolant system is a closed system, and includes the = expansion tank. As the coolant warms up it expands. The expanding coolant must = go somewhere, so the pressure cap on the expansion tank opens, and = vents coolant into the overflow tank. Once the engine is off and is = cooling down, the coolant shrinks, a suction occurs, and the coolant is drawn back = into the expansion tank.

I have found that replacing the sensor and the thermostat = every year contributes to good health of the cooling system.

Hope this helps.

John Rodgers
"88 GL Driver

Andrew Grebneff wrote:

I've never been able to work out what the flashing red LED in my 84
Caravelle's instrument cluster is = for. It starts flashing on startup, and
goes out some time later. A = couple of times it's come back on while
driving, but doesn't seem = to be warning of high coolant temperature.

What IS this LED for? I don't have a owner's manual and that = paragon of
incompleteness the Bentley manual doesn't mention it.

Andrew