Dash temp guage goes to red on 2000 ford focus dohc zetech

New thermostat, installed, saw, new coolant made a little mess filling reservoir, (normal) checked fan fuse for some reason, and condenser fan fuse (xxx ?:), and temp guage, is slightly lower on gauge (than normal?) (disconnected xxxx? quit? a bit? to get to thermosta?.t no dash warning lights have a feeling I popped a relay.

Answer:

ok, you did a coolant service with STAT,

and it failed.

tell us what works right and wrong, symptoms only.

over heating? parked, (fan never comes on)? as it hits 225F?

under heating? ( fan stuck on , up North can cause huge cold engine)

dash gauge stuck low. (thermostat wrong heat range 180f is best. see FSM for spec. on this temp. spec..

Dash guage varies.? oddly (air in system)?

Dash gauge too high.? (Stat put in upside-down or bleed hole (jiggle) not UP side. higher side of mount , trapping air.)

Does something wrong happen only driving?

leaks?

does cap on rad hold 12-14psi pressure, hot.?

if car has fan belts, are they tight? (for sure water pump does)

Check the heater hoses for warmth at the heater core. Some designs do not use a waterflow valve, but instead always have heater core flow and use the air flaps to regulate heat.

Now there is a difference in some thermostats and the housings. Barely noticeable are the locking tabs inside the housing and on the thermostat ring. If you have this setup and the thermostat is not locked in place, you could get some bypass around the thermostat.

If you have an electric cooling fan, the Relay may be stuck, keeping the electric cooling fan running when it should not. This would overcool the engine.

Please rate my info.

Check the operation of the cooling fans at the radiator. While idling disconnect the coolant temp sensor at the top left (drivers side) of the engine. It will be a 2 wire connector near the thermostat housing. When disconnected the coolant fans should come on immediately, if not you have an electrical issue with the relays or blown fuse. Check the fuses first in the underhood electrical panel. Next swap the cooling fan relay with an identical one next to it, if the fan works the relay is open.

sounds like possibly the coolant fan inop check that

Check the fan relay, it is the only relay inside the power distribution box, under hood on the lefthand fender just behind the air cleaner box. This relay sometimes has bad or dirty connections. Also check the temperature sending unit that activates this relay, it is located in the heater hose directly under the ignition coil, the hose runs between the thermostat housing and the firewall, there are two sensors here the single wire sensor is for the dash guage. Hope this helps, let me know.

first check and see if you have flow through the heater core
start the car and get to operating temp. then grab the heater hoses they should both be hot if not then you have a flow problem
you can try and back flush the heater core or replace it
if the hoses are hot then there will be a problem with the temp door under the dash
hope this helps let me know if you need more info on the heater door

you need to see where the temp sender is on the engine,and check the electrical plug ,it may be lose or dirty,make the obvious like battery terminals are tight and you havent washed the engine recently,as water will do this possibly gauge but unlikely

If the hoses to and from the heater core are hot , and you say the heater core is hot , then the only answer is that the air duct that flows into or out of the heater core plenum ( housing ) is not opening.
Heater control on dash borad inoperative.
Not sure about 92 capri , some cars have a cable linkage , some work on vacume motors.
Try to find a haynes manual for your car , they will walk you through almost every step of anything you may ever want to do to your car.

You seem to know what you are doing , but I gotta ask ........the heater core you felt was up behind the dash inside the passenger compartment of the car right ?

i would try the water pump first to do the heater core on that im pretty sure you have to pull the dash good idea when you change the water pump replace the timing belt easy job if u have the 2.0dohc hope this helps

Replace the thermostat first. Make sure the antifreeze level is full. Bleed the system. most car's have a bleeder valve located at the thermostat housing outlet.Drain the coolant level only to below the thermostat where it won't leak when removing the housing and thermostat. If it's the heater core it is located under the dash where the 2 heater hoses enter the cab from the engine compartment.