Yes, that is right. At least on 2.1 2wd models the temp sender for the
gauge is in plastic, sticking through into the coolant flowing by. If no
coolant is flowing the sender won't get a true reading of the engine
temp as the plastic does not transmit heat very well. The coolant level
warning system is a backup system to give a warning before the meltdown,
no matter which engine you have.

The level warning system is not that complicated but some people are
befuddled in their attempts to fix or even understand it. It does not
help that models before 85 had a level warning relay that pegged the
needle when it triggered the led, leading to confusion over what was
happening. Everyone should update to the later versions of the relay
that was fitted during the 85 model year and all after.

It also does not help that 85 and older vans hide the warning relay
inside the dash where is is difficult to see, much less put your hand on.

Mark

Edward Maglott wrote:
> I thought the reason for the low coolant light was that the temp
> sender for the gauge is not in the engine like in a normal car. It's
> remote in the thermostat housing. So if you get a sudden loss of
> coolant the gauge might not even register elevated temp because there
> would be no hot coolant hitting the sender. Is this right?
>
> Thanks,
> Edward
>
> At 11:04 AM 9/21/2011, Don Hanson wrote:
>> I probably would not even own my vanagon now if I'd heeded that LED
>> warning
>> light, which was flashing when I bought the van near Tacoma and drove
>> a few
>> hundred miles home. In fact, it may *still* be flashing, over 65k miles
>> later...I just taped it over, after about 3 frustrating attempts to
>> make it
>> work consistently and correctly.
>