Subject: thermostat?

C1J1Miller at C1J1Miller at
Mon Jan 24 09:23:17 EST 2005

Dan Wing writes:
Could the thermostat (2 and 1/2 years old) stick in such a way as to trigger the sensor for the warning, while the temp gauge still reads OK?

Dan:  I think Phil may be on the right track; you may have a bad fusible link.  Driver's front inner fender, in a small black box, attached to the brown ground side wire of the fan.  May look good, but not provide continuity.

80-amp fusible link from the dealer; a VW dealer may have one even; seem to remember the diesels using a similar one. 

The cover of the box often breaks off; replace it if possible (electrical tape can hold the cover on).  The cover keeps the salt spray from the fan from corroding the link.

If you are losing coolant, check carefully to find the source.  Overheating due to a bad fan fusible link may have cracked the after run coolant pump housing, and it may seep, especially when the system is fully pressurized.  It can let go and drain all the coolant quite fast, so if it is bad, pull it and put in a length of pipe or a new pump. Of course there may be other sources for the leak; another plastic bit to check is the coolant control valve for the heater, located below the idle stabilizer valve by the firewall.  Oh, and the little hose across the front of the head... etc.


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