oddball
Dedicated LVC Member
There's got to be at least one, right?
Please, please, please, pretty-pretty-please put a scope on the white/black wire (small gauge) going to the radiator fan and let me know what kind of signal is used. A simple sample when the engine is cold and when a/c compressor is on would probably be enough.
I'm making headway on getting an '04 fan into my '02. Wiring should come from the engine compartment electrical box pretty easily, although I'll be verifying wire sizes this weekend. Tried a variety of resistances and PWM signals to no avail. Only get full speed. Granted, the hydraulic system has two speeds: barely spinning and full blast. So this may not be a big deal, but I'd like to dial down the full speed if possible, without trying to limit or PWM the motor power line.
immusicman's notes from his experiment are over here. I expect to power the fan from the main lug on the elec panel, ground somewhere convenient. The control line is, of course, the problem. If I can't crack that nut, then I'm pretty sure I can do a simple transistor setup to use the existing hydraulic solenoid signal to drive the computer +12V hot when the PCM wants the hydraulic fan, thus running the elec fan at full blast. Tying the control line to anything seems to be enough to keep the circuit from losing the magic smoke. Oddly, various searches on all the chip id's in the fan module turn up nothing. Can't see the signal traces because they're on the bottom of the board, but I may try pulling that out of the module. Looks like it's soldered in place for the high current leads to the motor, but worth a try. If the control line gets cracked, then the +12V will be wired like they expect it and I'll use the hydraulic solenoid signal to drive my own circuit to send the desired signals. Hopefully.
That thing moves a ton of air. Bench testing has nearly killed my so-so beater battery (with a charger providing most of the current, of course). Bonus: blew all the crap out from under my workbench.
Thanks!
Please, please, please, pretty-pretty-please put a scope on the white/black wire (small gauge) going to the radiator fan and let me know what kind of signal is used. A simple sample when the engine is cold and when a/c compressor is on would probably be enough.
I'm making headway on getting an '04 fan into my '02. Wiring should come from the engine compartment electrical box pretty easily, although I'll be verifying wire sizes this weekend. Tried a variety of resistances and PWM signals to no avail. Only get full speed. Granted, the hydraulic system has two speeds: barely spinning and full blast. So this may not be a big deal, but I'd like to dial down the full speed if possible, without trying to limit or PWM the motor power line.
immusicman's notes from his experiment are over here. I expect to power the fan from the main lug on the elec panel, ground somewhere convenient. The control line is, of course, the problem. If I can't crack that nut, then I'm pretty sure I can do a simple transistor setup to use the existing hydraulic solenoid signal to drive the computer +12V hot when the PCM wants the hydraulic fan, thus running the elec fan at full blast. Tying the control line to anything seems to be enough to keep the circuit from losing the magic smoke. Oddly, various searches on all the chip id's in the fan module turn up nothing. Can't see the signal traces because they're on the bottom of the board, but I may try pulling that out of the module. Looks like it's soldered in place for the high current leads to the motor, but worth a try. If the control line gets cracked, then the +12V will be wired like they expect it and I'll use the hydraulic solenoid signal to drive my own circuit to send the desired signals. Hopefully.
That thing moves a ton of air. Bench testing has nearly killed my so-so beater battery (with a charger providing most of the current, of course). Bonus: blew all the crap out from under my workbench.
Thanks!
