Ive got a 97 thunderbird Lx 3.8l i got from grandmom. The damn radiator fan isnt coming on. I replaced the fan itself, still not working. Replaced the engine coolant temperature sensor, not working. The fan turns on when i unplug the temperature sensor but turns off when i plug it back in. It briefly turned on one time when i turned the AC on high but then it turned off in 5 seconds and i couldnt get it to turn on again. I swapped the radiator fan relay and nothing happened.The car also has various other problems like the odometer and speedometer dont work. I figured that was a bad sensor, but now im wondering if the car has a bad ECU? only thing i can think is its got a bad ecu or fucked up wiring somewhere. Any ideas before i go and buy a new ecu? I havent checked the codes yet, never really fucked with code readers and im an idiot when it comes to electrical shit.The car only has 40,000 miles but it wasnt run for a few years
LS swap
>>28934953Hardwire it to run all the time what could possibly go wrong.
>>28935024I mean i can unplug the temperature sensor and it runs all the time but i want to get it running right
>>28934953>The fan turns on when i unplug the temperature sensor but turns off when i plug it back inThe PCM sees "Infinite Resistance" (Open Circuit). On a 1997 Ford, this triggers a Failsafe. The computer says, "I don't know the temp, so I'm turning the fan on High just to be safe."try this:Pull the ECT harness, and jumper it with a paperclip.You are creating a "Zero Ohms" (Maximum Heat) condition, and the Fan should activate.IF IT DOES, this indicates that our wiring to the PCM is perfect, and that the PCM is operating properly (on this circuit at least)NEXT would be to crawl under and check for melted VSS wiring Unplug VSS (at Transmission)If fan/A/C returns, the speed sensor wiring is melted/shorted.REPORT BACK
It's the fan relay. You're welcome.
>>28935052>You're welcome.You're wrong.The Path: PCM CCRM (Relay) Fan Motor.The fan activates in FAILSAFE mode, when he pulls the ECT sensor out of the equation.
>>28935056Retard. That's a completely different circuit with it's own relay.
>>28935052Already triple checked the fan relay>>28935047>check the VSS wiringI didnt know the VSS could fuck with the radiator fan somehow, but if it can then this is likely the issue, because im pretty sure my odometer and speedometer are broke because of something bad with the VSS. I might crawl under there tonight but if not ill report back tomorrow. Thank you for the advice!
>>28935064It doesn't he's retarded redditor.
>>28935064>I didnt know the VSS could fuck with the radiator fan somehowAlso related to the other symptoms:Inoperative Speedo and Odometer
>>28935064>I might crawl under there tonight but if not ill report back tomorrow.Also check Fuse 18.Best of luck bro.I'm willing to bet that the VSS harness is melted, as it is close to exhaust
