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The other day my blower motor stopped working. The fuses instantly blow when the HVAC is turned on. I have replaced the blower motor and relay. Has anyone had this issue before or can help lead me in the right direction?
The fuses instantly blow when the HVAC is turned on. I have replaced the blower motor and relay.
1) Do both fuses blow?
2) You replaced the relay located behind the fuse block?
3) Any evidence of water intrusion? Wet cabin air filter, wiring connector, etc.?
1) Do both fuses blow?
2) You replaced the relay located behind the fuse block?
3) Any evidence of water intrusion? Wet cabin air filter, wiring connector, etc.?
Both fuses blow
yes I replaced the one behind the fuse panel
I had a leak several months ago but I haven’t seen it since after I replaced a sunroof line
I would still recommend you check the cabin air filter and blower motor for water. You could have a secondary leak (windshield cowl). Just happened to a fellow member on his Coupe.
That said, do you have a digital multimeter? I would suggest you disconnect the harness at the blower motor and with good fuses/ key ON, check for:
A) 12V+ at the blue wire/ terminal on the connector. This wire will always be "HOT" while the key is on regardless of AC settings.
B) Check continuity between the black wire/ terminal and a good, solid metal part of the body.
For both fuses to pop there has to be a short somewhere- whether it be a frayed wire or a issue with the connector/ blower motor. The likely reason they only pop when you turn the AC on is that the blower receives a control signal from the AC Amplifier (pink wire) to turn on/ regulate speed.
It wouldn't hurt to check the electronics on the blower motor itself. Another member had corrosion develop on one of the circuit traces which eventually blew the blower amp.
Yes I will definitely check the continuity through the wires to the fuse box and the ground with my multimeter. I will have to also check if the fuses blow if the blower is unhooked I ran out of fuses. I replaces the blower motor so the electronics shouldn't be a problem. my cabin air filter has been slightly damp, I believe it was an issue with the cowling and replaced the filter and made a better seal with the windshield. My question is, could this be an issue with the BCM? I was thinking maybe it got damp and corroded and could be causing this issue. However, I don't believe the wiring that goes from the fuse box to the blower would pass through the BCM since the relay to switch it on is in the fuse box and controlled by the BCM. Do you happen to know if that is the case and could rule the BCM out?
It is not the BCM. There are only 3 factors to this equation:
1) power (fuses, relays, etc.);
2) ground; and
3) control signal (from AC amp).
The AC amplifier (white box mounted on AV headunit) sends the control signal to the blower (via pink wire) to turn on/off and regulate speed.
Being that the fuses pop when you try to turn the blower on, indicates the issue lies downstream from the fuse block. It sounds like you have a solid plan in place for testing the circuits.
Where did you buy the replacement blower motor from? Just because it is new does not guarantee it will work- or be the right one for the car...
It is not the BCM. There are only 3 factors to this equation:
1) power (fuses, relays, etc.);
2) ground; and
3) control signal (from AC amp).
The AC amplifier (white box mounted on AV headunit) sends the control signal to the blower (via pink wire) to turn on/off and regulate speed.
Being that the fuses pop when you try to turn the blower on, indicates the issue lies downstream from the fuse block. It sounds like you have a solid plan in place for testing the circuits.
Where did you buy the replacement blower motor from? Just because it is new does not guarantee it will work- or be the right one for the car...
I took the blower motor out of a G35 I am parting out because no where around here had a new one in stock. Could that AC amplifier have the potential to short out/ blow the fuses instantly? Do you know if that box controls the heated seats? My heated seats randomly turn on every other time I turn my car on. If that could blow the fuse it might be that going out. My thought would be if it was going out the motor wouldn’t spin but fuses wouldn’t blow. Do you think that makes sense or do you think that could make the fuses install blow?
I took the blower motor out of a G35 I am parting out
I can see two potential red flags here. ¹ the blower is used/old to begin with, and ² there may be slight compatibility differences between the blower motors' amps (the blower has a internal amp of its own).
Originally Posted by ZipTieRacing
Could that AC amplifier have the potential to short out/ blow the fuses instantly?
Unlikely. The amp only sends a control signal to the blower- it does not provide power to the motor. For both fuses to pop like they are, the issue lies in either the wiring from the fuse block to the blower, or within the blower itself.
Originally Posted by ZipTieRacing
Do you know if that box controls the heated seats?
Negative. The AC amplifier controls just about everything related to your gauge cluster, HVAC, and some other subsystems like the paddle shifters and fuel level, etc. The amp is not tied to the heated seats. They have their own dedicated relay, switches, etc. If the switch(es) are OFF then the heaters should not turn ON.
Originally Posted by ZipTieRacing
My thought would be if it was going out the motor wouldn’t spin but fuses wouldn’t blow. Do you think that makes sense or do you think that could make the fuses install blow?
The motor could easily be fine and have zero issues/rotate freely. The problem may be with the amp that is built into the motor which controls the magnetic field. If those electronics are shot, then when the AC amp tries to turn the blower on, the faulty circuit pulls too much juice and the fuses pop.
I can see two potential red flags here. ¹ the blower is used/old to begin with, and ² there may be slight compatibility differences between the blower motors' amps (the blower has a internal amp of its own).
Makes sense I will try to get a new one. I just figured the plugs are the same so I figures Nissan would just reuse the same stuff. Couldn't get one for several days so tried that.
Unlikely. The amp only sends a control signal to the blower- it does not provide power to the motor. For both fuses to pop like they are, the issue lies in either the wiring from the fuse block to the blower, or within the blower itself.
The switches are defiantly off and have tried unplugging them as well and still does it. What controls the heated seats?
Negative. The AC amplifier controls just about everything related to your gauge cluster, HVAC, and some other subsystems like the paddle shifters and fuel level, etc. The amp is not tied to the heated seats. They have their own dedicated relay, switches, etc. If the switch(es) are OFF then the heaters should not turn ON.
The switches are defiantly off and have tried unplugging them as well and still does it. What controls the heated seats? I saw the fuse was tied into a bunch of other things so I didn't pull it. Is there an easy way to just disable them for the time being? Do you happen to know which plug it is on the seat? I couldn't get the repair manual to load to find the diagram
The motor could easily be fine and have zero issues/rotate freely. The problem may be with the amp that is built into the motor which controls the magnetic field. If those electronics are shot, then when the AC amp tries to turn the blower on, the faulty circuit pulls too much juice and the fuses pop.
Ill check the board on the old one for corrosion in the meantime while I wait for a new one to come. Thank you for your help
If you have the heated seat switches disconnected and the seat heaters are still coming on then the relay is either stuck closed or something is grounding the coil thereby keeping the relay closed whenever the car is powered on.
The only way to fully disable the seat heaters is to pull the relay or you can pull fuse #35 in the fusible link relay box (fuse box near battery) The relay should be located behind the HVAC/preset switch panel (the one with the clock) and to the right (nearest the glove box). Probably easier to pull the fuse...
From the FSM:
Last edited by ILM-NC G37S; 06-29-2021 at 05:04 PM.
06-28-2021, 04:39 PM
