Nissan Pathfinder: No Heat / Blower Motor Stops Working
video description
Date: 2020-10-01
Related videos
Comments and reviews: 9
hrep14
I had a problem with a headlight once on an old Nissan where the passenger side would work sometimes then not, eventually it died. I downloaded numerous workshop manuals for the make and model and traced the wiring in the car from the battery to the fuses to the headlight all the way back to the combination switch in the car. I tested the switch which seemed to be working with an ohm meter. I tested the bulb on the other headlight it was okay, I switched out the bulb connector still nothing. I was scratching my head trying to pin point the problem. Then I noticed a little sealed black box bolted on the drivers side near the radiator overflow tank. Which was missing from schematics of all the drawings I saw. So I removed the plugs and tested the wires and found they were connected to the circuits I was testing. Eventually I pried open the unit using a small Phillips screwdriver and a flexible putty knife, it turned out to be a relay unit. So I plugged the connectors back on with the cover off and sure enough it was for the headlights and turned out some of the relays weren t working properly so I resoldered all the joints on the circuit board and the faulty headlight came back to life. That was my one and only experience with electrical schematic on a car, if the darn thing had been on the drawings I had it would have saved me a couple of weeks. It was a Japanese assembled car so I gather there may have been differences in the assembly for those assembled out side of japan. Everything else in the manual seems okay as I ve used the same manual a few times to do other repairs.
reply
I had a problem with a headlight once on an old Nissan where the passenger side would work sometimes then not, eventually it died. I downloaded numerous workshop manuals for the make and model and traced the wiring in the car from the battery to the fuses to the headlight all the way back to the combination switch in the car. I tested the switch which seemed to be working with an ohm meter. I tested the bulb on the other headlight it was okay, I switched out the bulb connector still nothing. I was scratching my head trying to pin point the problem. Then I noticed a little sealed black box bolted on the drivers side near the radiator overflow tank. Which was missing from schematics of all the drawings I saw. So I removed the plugs and tested the wires and found they were connected to the circuits I was testing. Eventually I pried open the unit using a small Phillips screwdriver and a flexible putty knife, it turned out to be a relay unit. So I plugged the connectors back on with the cover off and sure enough it was for the headlights and turned out some of the relays weren t working properly so I resoldered all the joints on the circuit board and the faulty headlight came back to life. That was my one and only experience with electrical schematic on a car, if the darn thing had been on the drawings I had it would have saved me a couple of weeks. It was a Japanese assembled car so I gather there may have been differences in the assembly for those assembled out side of japan. Everything else in the manual seems okay as I ve used the same manual a few times to do other repairs.
reply
Alexis
It's important to survey the motor inrush current, bad brushes or simply bad second market motors simply need too high currents to start when cold, particularly in low speed, so a so called resistor block can get into trouble and into protection. On the other hand, shock starting can also indicates bad circuitry inside this command block, typically bad solders, with the same effect. It can also indicates a dying transistor or broken PCB, something easy to solve with time and knowledge cuba style, or simply replace with OEM part.
Note these blowers motors have the typical vertical configuration, contact brushes down, so if dirt and humidity get stuck there, life expectancy is highly reduced. Here also, replacement is easier than stripping parts out plastic encasing, but a direct high pressure air flow can sometimes do the trick and remove most of the dirt if brushes are still good and free in guides, and rotor turning free. So unmounting this motor for cleaning and checking currents is also an interesting option.
reply
It's important to survey the motor inrush current, bad brushes or simply bad second market motors simply need too high currents to start when cold, particularly in low speed, so a so called resistor block can get into trouble and into protection. On the other hand, shock starting can also indicates bad circuitry inside this command block, typically bad solders, with the same effect. It can also indicates a dying transistor or broken PCB, something easy to solve with time and knowledge cuba style, or simply replace with OEM part.
Note these blowers motors have the typical vertical configuration, contact brushes down, so if dirt and humidity get stuck there, life expectancy is highly reduced. Here also, replacement is easier than stripping parts out plastic encasing, but a direct high pressure air flow can sometimes do the trick and remove most of the dirt if brushes are still good and free in guides, and rotor turning free. So unmounting this motor for cleaning and checking currents is also an interesting option.
reply
Billy
Thank you Dr. O. So the question is on control operation? Does blower motor control module (resistor, but really not a resistor) supply a signal reference voltage to the AC Amp Control Module, and this signal is pulled down to 0 VDC to signal off position. Then when speed switch is selected, the AC Amp Control Module toggles this signal off of ground at varying PWM to signal the Blower Motor Control Module to the desired speed? Or, does the Blower Motor Control Module not supply a signal reference voltage to the AC Amp Control Module, then the AC Amp Control Module only sends the PWM signal to the Blower Motor Control Module? Reason I ask, if you were to unplug the Blower Motor Control Module and test the signal wire for voltage and PWM signal, would it read 0 VDC in the off position and a PWM signal in the other speed selections?
reply
Thank you Dr. O. So the question is on control operation? Does blower motor control module (resistor, but really not a resistor) supply a signal reference voltage to the AC Amp Control Module, and this signal is pulled down to 0 VDC to signal off position. Then when speed switch is selected, the AC Amp Control Module toggles this signal off of ground at varying PWM to signal the Blower Motor Control Module to the desired speed? Or, does the Blower Motor Control Module not supply a signal reference voltage to the AC Amp Control Module, then the AC Amp Control Module only sends the PWM signal to the Blower Motor Control Module? Reason I ask, if you were to unplug the Blower Motor Control Module and test the signal wire for voltage and PWM signal, would it read 0 VDC in the off position and a PWM signal in the other speed selections?
reply
kd9bwi
Not too long ago when I was super involved with the ham radio community, somebody came out with a diy kit for a pocket oscilloscope. I picked one up for 50 bucks, not bad for testing radio circuits but man the sample rate was terrible. It s good to see that a commercial product is available, I shall pick one up. By the way, does anyone know of a cheap and not too junky smoke machine? I believe I have the classic Chevy plastic intake leak that carb clean won t find. I got a lean misfire on all cylinders but no traceable vacuum leak. Fuel pressure good and MAF is clean, carb spray not picking anything up.
reply
Not too long ago when I was super involved with the ham radio community, somebody came out with a diy kit for a pocket oscilloscope. I picked one up for 50 bucks, not bad for testing radio circuits but man the sample rate was terrible. It s good to see that a commercial product is available, I shall pick one up. By the way, does anyone know of a cheap and not too junky smoke machine? I believe I have the classic Chevy plastic intake leak that carb clean won t find. I got a lean misfire on all cylinders but no traceable vacuum leak. Fuel pressure good and MAF is clean, carb spray not picking anything up.
reply
vmct92
Hi i have a 2006 nissan sentra and there is no pulse in the injectors, if I put a led test light it blinks very dimly, the positive is ok, if I spray gasoline through the intake the engine starts. What do you recommend apart from reviewing ground and positives of the ecu?
reply
Hi i have a 2006 nissan sentra and there is no pulse in the injectors, if I put a led test light it blinks very dimly, the positive is ok, if I spray gasoline through the intake the engine starts. What do you recommend apart from reviewing ground and positives of the ecu?
reply
Gee
I left you a negative feedback whatever those things are called. You are you need to work on your mouth breathing. It's almost like somebody who eats with their mouth open but you're just breathing with your mouth open. Kind of makes people cringe no offense or anything
reply
I left you a negative feedback whatever those things are called. You are you need to work on your mouth breathing. It's almost like somebody who eats with their mouth open but you're just breathing with your mouth open. Kind of makes people cringe no offense or anything
reply
Bobbywolf64
Where do you get the handy little T-pins that you use all the time? Are they a product you can buy? or are they something common that you re-purpose for this? Genuinely curious as I want to get my hands on them.
reply
Where do you get the handy little T-pins that you use all the time? Are they a product you can buy? or are they something common that you re-purpose for this? Genuinely curious as I want to get my hands on them.
reply
Alan
I am glad that I didn't purchase a Nissan Pathfinder. I got a Honda CRV instead. I wanted a Toyota 4Runner, but the dealers NEVER had a vehicle in, with the options that I wanted. One day, I will get a Subaru.
reply
I am glad that I didn't purchase a Nissan Pathfinder. I got a Honda CRV instead. I wanted a Toyota 4Runner, but the dealers NEVER had a vehicle in, with the options that I wanted. One day, I will get a Subaru.
reply
Evan
Starting a new job in a couple weeks working on lift trucks (forklifts) and other various equipment. A lot of these are electronic and I'm hoping someday I'll be as good as you at being an electrical guru.
reply
Starting a new job in a couple weeks working on lift trucks (forklifts) and other various equipment. A lot of these are electronic and I'm hoping someday I'll be as good as you at being an electrical guru.
reply
Add a review, comment
Other channel videos
