Stupid question, Where is the blower motor fuse/relay for 99 gs4?
03-19-12, 09:55 PM
#61
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i think i ruled out the a/c control unit since it controls the subaru resistor, just the speeds are backwards. as far as body ecu 1 controlling the fan relay, i think im gonna find a wire to tap at the back of the climate control that i can use to signal a relay to ground the purple wire when the unit is turned on, and bypass body ecu 1 all together, since that was my original problem just like the OP.... so i either need a lexus blower resistor, or im going to make a circuit that allows me to use a subaru resistor and have the fan speeds the right way around. I cant believe how much money they want for the lexus resistor, that is insane.
04-25-12, 09:55 PM
#66
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i bought a blower resistor from lexxtacy and installed that, and grounded the signal wire for the blower relay so the relay is on all the time, taking body ecu 1 out of the equation. hvac works properly now. im probably going to use a relay and find a signal wire on the back of the hvac control unit to trigger it, and use that to control the grounding of the blower relay so its not on all the time, but for now its working.
04-28-12, 01:29 PM
#68
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hey sam, yeah the problem is still there for me, i think it has something to do with my battery drain as i unplug a connector in the passenger side interior fuse box and it seems to work and my battery drain goes away however with it unplug i dont have the automatrc steering tilt or cd player or interior lights and passneger side turn signal wont work so im trying to figure out what the colors on the plug are for because its the red wire and green wire, having trouble though.....
08-02-16, 09:17 PM
#70
Would like to know as well. I'm not as far along in diagnosing but I know this: The control panel appears fine, unable to test the resistor as there is no power coming from the heater relay in the passenger side kick panel. But the relay clicks when turning the car on. The relay may be bad, but the hot wire to the resistor is somehow grounding somewhere. Maybe the relay, who knows. I was able to get a complete circuit probing the hot wire and the signal wire to check that the control panel is functioning.
08-12-16, 11:27 PM
#71
UPDATE:
The reason the blower only works when the "heater" fuse is pulled is because there is voltage backfeeding up the purple ground wire that is supposed to go from heater relay to body ECU. With the 10A heater fuse installed, both sides of the heater relay magnet become positive and there can't be a complete circuit. But remove the 10A fuse and that side of the circuit becomes ground and activates the magnet and the blower works.
The click I was hearing from the relay when turning the car ON was actually the relay shutting off as both positive currents collided and deactivated the magnet.
Still haven't figured out why, in my case, the wire that should be grounded is supplying 12v positive. I would suspect the body ECU but nothing else is malfunctioning. Possibly an improperly-routed wire somewhere or a bad ground. Not sure where to look for more ground points though, I've cleaned the ones on the fenders but that didn't help at all.
The reason the blower only works when the "heater" fuse is pulled is because there is voltage backfeeding up the purple ground wire that is supposed to go from heater relay to body ECU. With the 10A heater fuse installed, both sides of the heater relay magnet become positive and there can't be a complete circuit. But remove the 10A fuse and that side of the circuit becomes ground and activates the magnet and the blower works.
The click I was hearing from the relay when turning the car ON was actually the relay shutting off as both positive currents collided and deactivated the magnet.
Still haven't figured out why, in my case, the wire that should be grounded is supplying 12v positive. I would suspect the body ECU but nothing else is malfunctioning. Possibly an improperly-routed wire somewhere or a bad ground. Not sure where to look for more ground points though, I've cleaned the ones on the fenders but that didn't help at all.
06-04-17, 11:11 AM
#72
Info for anyone searching for a solution to the same problem. If you pull the 10A HTR fuse in the driver's side kick panel and your blower starts working, this is what you do to fix it:
Remove interior panels that hide the passenger fuse box. On the bottom left hand corner of the box assembly is a wire harness plug thing. This is plug 2F in the EWD. Coming from this plug is a purple wire. This purple wire has to be grounded to activate the fan relay, but for whatever reason it's feeding 12v positive. I never figured out why. The solution is to cut this purple wire and ground the end coming out of the cable wrapping. Do not ground the end that comes out of the panel plug or the ECU-B2 fuse will blow.
I don't know why the wire that's supposed to be ground is feeding positive instead, and nothing else is wrong with the car. Some say changing the body ECU fixes it, others not so much. Either way, this eliminates a redundant ground switch and restores normal operation.
Remove interior panels that hide the passenger fuse box. On the bottom left hand corner of the box assembly is a wire harness plug thing. This is plug 2F in the EWD. Coming from this plug is a purple wire. This purple wire has to be grounded to activate the fan relay, but for whatever reason it's feeding 12v positive. I never figured out why. The solution is to cut this purple wire and ground the end coming out of the cable wrapping. Do not ground the end that comes out of the panel plug or the ECU-B2 fuse will blow.
I don't know why the wire that's supposed to be ground is feeding positive instead, and nothing else is wrong with the car. Some say changing the body ECU fixes it, others not so much. Either way, this eliminates a redundant ground switch and restores normal operation.
08-13-19, 02:27 PM
#74
Not sure if you're still looking for this.. but for anyone else that needs a blower motor relay you can get a new denso one for cheap from rockauto.
https://www.rockauto.com/en/catalog/...tor+relay,3088
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