Temp guage does not work, fans do not come on

Most often caused by a bad fan relay. This is a complicated system. Read the post below and download the GM wiring diagrams. Then check the fuses and relays. All 3 relays must be in perfect working order for the system to work properly.
Car overheats Ricks Free Auto Repair Advice

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)

Unplug the temp sensor and see if the guage changes, then ground the wire going to guage at the sensor and see if guage pegs out. You may have the wrong sending unit, the one for a guage is different then the one for a light.

First question is: does the fan come on at all, even as the temp begins to rise on the guage?
If not, check the relay or the sender for the temp (that may be what you replaced) Then look at the connections for the fan--- and, have you checked the fan for operation with known 12v source?

1st do you loose water from the header tank or water dripping anywhere under car when stopped yes or no if yes to loss of water from h/tank then the problem is you have a Head Gasket blowing compression into the water jacket next to the cylinder,and its only small now but will get worse very soon, so get the Head removed and cracked tested and Head surface ground . Ron

This is a case of AC fan on radiator not working. The fan, one of two, comes on when you turn on the AC. Well, supposed to come on.. Have that fan chk'd

Check the temperature switch, which is mounted on the rear of the cylinder head (driver side, upper engine area), and also the cooling fan control. Both of these signal when the cooling fan should come on, and it sounds like it's kicking on too late.

hey if it was constantly running at these temps you would dhave definately damaged the engine by now. the temp guage is integrated with the instrument cluster and not replaaceable unless the whole guage cluster is replaced. you could go to a professional installer and have an aftermarket temp guage installed. much cheaper than having your instrument pannel replaced. in addition to the instrument pannel being replaced the odometer millage must be programed into the new pannel. if the fans are not turning on the engine more than likely is not getting hot enough to turn them on. but just to be sure i would take the vehicle to a automotive diagnostic specialist to make sure the ecm (electronic control module) is performing correctly. it may not be sending the signal to the fan relay to turn the fan/ fans on. you may also have a faulty temp sending unit. good luck. SMB......

Check the Tension on the Belt First. If it is even a Little loose it will not allow the Alternator to Charge The Battery.