1990 200tqw-overheating

[Arryn Milne]

Based on Dad's '87 5ktqw:
There are three relays for the fan: Stage 1, Stage 2, and Stage 3.  Stage 
one comes on with the afterrun system, stages two and three are triggered 
from the thermoswitch in the radiator.  There are two relays in the fuse 
panel (in locations 1 and 6 I think), and one in the dash above your knees.
If you jump the motor, use decent wiring as it draws about 40 amps.  Don't 
forget the resistor pack in front of the radiator.
Things to check:
fan
wiring
relays
resistor
thermoswitch
http://www.sjmautotechnik.com/cooling.html
Happy hunting,
Arryn


At 08:57 AM 12/27/00 -0500, Ron Frazier wrote:
>I need some help trouble shooting an overheating problem. The coolant
>warning light comes on as the temmperature of the coolant gets in the
>vicinity of where or past where the fan should kick in.  I originally
>thought it was the thermostat but I replace it and it didnot change.  I also
>put in a new reservoir because it was slightly leaking.  I think the
>overheating problem must be caused by the fan not coming on. I checked the
>fuse box and it seemed ok.  Two summers ago I had a problem with the fan not
>running when the AC was on.  I replaced the radiator thermo switch to
>correct that problem.  I have yet to put 12v on the fan motor to see if it
>is working.  I understand that there is a fan relay that is under the dash
>that could be a problem.  Where is this thing?  Also there is a thermo
>switch at the top hose connection to the head that sends the temp gauge data
>and alarm to the  instrument panel and controls the fan?  Could this be part
>of the problem eventhough it is sending the alarm and the temp gauge seems
>to work as usual.  What are the other two sensors in this connection.  How
>does this relate to the radiator thermo switch.  The aluminum strip fuse in
>the fan wiring looks ok. Trouble shooting advice is requested.