cooling fan trouble on 89

[blackvette89]

can someone please help with a cooling fan problem. my fan comes on at 237 degrees. i changed one relay on the left fender. where exactly are the others. i can't seen any in plain sight at the raditor shroud. the fan closest to the motor is the one coming on. is this main or aux?? I grounded the sensor on right engine block with no results! Should the fan have come on when grounded. Any tips would be greatly appreciated. anyone with tips needed re: 89's i'll be glad to help!!:banghead: :banghead: :banghead:

[35thC4]

I'm no expert, but I thought the fan was supposed to come on at 237^

[MKOTZE]

Originally posted by blackvette89
can someone please help with a cooling fan problem. my fan comes on at 237 degrees. i changed one relay on the left fender. where exactly are the others. i can't seen any in plain sight at the raditor shroud. the fan closest to the motor is the one coming on. is this main or aux?? I grounded the sensor on right engine block with no results! Should the fan have come on when grounded. Any tips would be greatly appreciated. anyone with tips needed re: 89's i'll be glad to help!!:banghead: :banghead: :banghead: Hello Blackvette89, First off your vehicle has two cooling fans. One is the main fan and is closest to the engine. The other one is an auxiliary fan and is in front of the radiator. The main fan is supposed to come on at 226 degrees. The Electronic Control Module(ECM) is what controls the cooling fan. The relay that the ECM is controlling is at the front of the engine compartment on the left hand side of the radiator shroud.There is a fairly quick way to see if the ECM is controlling the cooling fan correctly. With the ignition key in the on position but the engine is not running you want to ground the A and B terminal together on the diagnostic connector, located under the left hand side of the dash in line with the gas pedal.If the ECM is working correctly the main cooling fan will come on. NOTE: On the diagnostic connector A is on the upper far right corner and B is to the left of A. If the cooling fan does not come on there is a problem with this circuit which could be either the ECM or the relay. If the cooling fan comes on during this test but does not come on when exceeding 226 degrees there could be a problem with the engine coolant sensor, which is mounted in the front of the intake manifold underneath the throttle body. As for the auxiliary fan, it should come on at 228 degrees and it is controlled by a switch in the left hand side of the engine in the cylinder head. If you need more information let me know or just le me know how things turned out. :chevy: MKOTZE

[blackvette89]

i did jump the diagnostic a to b and the main fan came on. I definetly only have one. the left block area is optional second fan and the block is plugged where the sensor would be, i recently bought the low fan temp sensor for the right side of the block. on at 200 and off at 185. do you think this will solve it?? i'm also gonna flush the system and clean the radiator!!:chevy: