Radiator Cooling Fan System - Change
87VW1Applies To
JETTA (from March 1986)
GOLF GL, GTI (8-VALVE), GOLF GT (from 1987 M.Y.) gasoline engine models only
Group
19
Subject
Radiator Cooling Fan System Change
Part Identifier 1908
Key Points
Radiator cooling fan timed run-on
^ To cool fuel lines and fuel injectors
^ To improve hot start characteristics A 278
Number
87-01
March 18,1987
Jetta, Golf GL, GTI (8-Valve) and Golf GT vehicles are now equipped with a radiator cooling fan timed run-on system to cool fuel lines and injectors after the engine is turned off to improve hot start characteristics.
How the system works
When the underhood temperature is higher than 110~C (230~F) after the ignition is turned off, the thermo switch will trigger the time relay to switch on the radiator cooling fan.
When the temperature falls below 103~C (217~F) the relay will turn off the radiator cooling fan.. This cycle will repeat once or more for maximum of 10-12 minutes.
WARNING
Never touch the radiator fan blades. They will rotate spontaneously when the time relay turns the fan on. Heat in engine compartment may cause repeat of this cycle more than once after the ignition is turned off.
New components
Thermo switch
Mounted on bracket on cylinder head (injector side) between cylinder one and two.
Time relay
After thermo switch is grounded, operates radiator fan at first speed for 10-12 minutes after ignition is turned off.
Golf GL, GTI (8-Valve), GT-Fuse relay panel position 13:
Jetta (Gas) - Fuse relay panel position 14:
Location
Troubleshooting
Time Relay
- switch ignition on and off
- connect thermo switch wire to ground. Make sure fan runs on first speed.
Note
Because the time relay is only operational for 10-12 minutes after the ignition is turned off, testing must be done within this time period.
Thermo switch
ON = Grounded when engine compartment temperature is over 110~C (230~F)
OFF = Not grounded when engine compartment temperature is below 103~C (217~F)
Electrical wiring
For electrical troubleshooting see wiring diagram:
Vehicle Wiring diagram Jetta (gas) Wiring Diagram Manual Golf, GTI, Jetta models 1985-1986 Service Publications No. W42 001 136 1
Golf GL, 86-56 of Sept. 22, 1986 GTI (8-Valve), Golf GT