Re: After run coolant pump??? 86' 5KCSTQ

[Pcarselle <pcarselle@worldnet.att.net>]

Martin Pot wrote:
> 
> After run coolant pump works smoothly if I put 12 V on it. Fan comes on when
> I bridge the thermoswitch. When I disconnect ground to fan and bridge
> thermoswitch, I hear the relay but coolant pump does not work.There are 3
> wires at the pump, 2 of them are together. If I separate the two mating
> wires and do the bridge test, the relay won't click. I just can't figure it
> out. Thanks, Martin.
Martin:

There are two thermoswitches involved ( I believe):
Injector Cooling Fan 
Turbo Coolant Pump
The injector cooling fan has its own control relay (15) which is
controlled by the Injector cooling fan thermoswitch, located to the rear
of the engine below the Idle Stabilizer Valve and close to the
wastegate  and mounted on a sheet metal type bracket part with a single
wire connection red/blue wire. If gounded, the relay will pull and the
cooling FAN should run. This cools injectors thru a metal shroud. 

The turbo coolant pump is controlled by the Radiator Coolant After Run
Relay (22), and the Turbo Coolant pump thermoswitch ( 2 wires Red from
Pump and Red/Green to Radiator Coolant Fan After run relay (22).
Two red wires must be together and connected to pump one has 12v the
other feeds Turbo coolant pump thermoswitch ( not the INJECTOR COOLING
FAN THERMOSWITCH).
If the two terminals of the thermo switch ( located in entrance of the
upper radiator hose into engine block with an hexagonal base )( two
wires red & red/green) are bridged, both the radiator cooling fan and
the and the injector cooling fan MUST run !
If they run, two possiblities in your case:
1) engine is too cold
2) bad thermoswitch
HTH
Pablo