Heater Blower Motor short
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- kassim503
- Posts: 1027
- Joined: 18 years ago
- Location: Stony Brook, NY
Heater Blower Motor short
For the past few days, Ive noticed that im getting a intermittent ground out in the wiring for the blower motor. This appears to only happen in speeds 3-4, and the short appears to be good enough to drop power to the point where it will reset the clock, drop the voltmeter to 0, and the motor will shut down due to loss of spark/fuel. Ive only noticed this on idle, and I checked the alternator belt, appears tight, and the alternator keeps spinnning while running the high beams.
After doing a brief scroll through the FSM, it shows that the switch passes through a resistor to regulate power to the motor from speeds 1-3 and it iss fused at the reisistors. It is also fused on the hot side through two 15A fuses. I have checked the fuses and they are correct, and IIRC, the back of the fuse panel shouldnt have any pins sticking out or dislodged, so there shouldnt be any shorts between the fuse blades.
From what I understand I shouldnt be grounding out anywhere from the switch to the motor, cause its the ground. And a short on the hot side of the circuitry wouldnt explain why im only grounding out in speeds 3-4. After mild guessing, I am pointing fingers at a faulty blower motor, but I dont really know why it would fail like this, and why the fuses and fusible links are not blowing when this occurs.
Any insight on this? This one sounds like a big dashboard pulling project
After doing a brief scroll through the FSM, it shows that the switch passes through a resistor to regulate power to the motor from speeds 1-3 and it iss fused at the reisistors. It is also fused on the hot side through two 15A fuses. I have checked the fuses and they are correct, and IIRC, the back of the fuse panel shouldnt have any pins sticking out or dislodged, so there shouldnt be any shorts between the fuse blades.
From what I understand I shouldnt be grounding out anywhere from the switch to the motor, cause its the ground. And a short on the hot side of the circuitry wouldnt explain why im only grounding out in speeds 3-4. After mild guessing, I am pointing fingers at a faulty blower motor, but I dont really know why it would fail like this, and why the fuses and fusible links are not blowing when this occurs.
Any insight on this? This one sounds like a big dashboard pulling project
'83 maxima sedan, l24e, a/t, black
227K SOLD 6/7/2012
227K SOLD 6/7/2012
- kassim503
- Posts: 1027
- Joined: 18 years ago
- Location: Stony Brook, NY
Update: I believe the blower motor might be partially shorted out, I am noticing a larger than normal voltage drop starting the fan on any speed, and actual power consumption on low (1). I think there might be a little water or moisture in the motor, it also makes a faint squeaking noise. Gonna attempt pulling the air box and cage to inspect tomorrow. From what I understand I may need to pull out a little more than the lower kick pad off the dashboard, the fsm says its only held on by three bolts, the third existing in the abyss deep in the dash
Edit: does anybody know what are the resistance readings supposed to be on these? I dont know much about electric motors, but I do know they consume more power under load and shorted windings may give me the symptoms that I have.
Edit: does anybody know what are the resistance readings supposed to be on these? I dont know much about electric motors, but I do know they consume more power under load and shorted windings may give me the symptoms that I have.
'83 maxima sedan, l24e, a/t, black
227K SOLD 6/7/2012
227K SOLD 6/7/2012
- asavage
- Site Admin
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- Location: Oak Harbor, Wash.
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Mark's '81 Wagon probably has a blower motor, should you need one.
Regards,
Al S.
1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
Al S.
1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
- kassim503
- Posts: 1027
- Joined: 18 years ago
- Location: Stony Brook, NY
Update, Did not inspect the fan today, spent my time frying bigger fish, such as checking parts from tailshaft to wheels for play. (Found play in all parts, thankfully there was only limited play in the cv joints)
The most interesting thing happened to me today, I stopped pretty hard to stay away from a few doe and fawn in the road, while traveling downhill. At the end of the stop I didnt reduce braking pressure too much so there was a abrupt stop and the engine hiccuped. Thought nothing of it and continued on my way, until I stopped downtown. A half abrupt stop at a stop light and the engine shut off. This was driving with the headlights on, fan on speed 1 or 2. I checked the connection from the fusible link to the battery post, will check quick connect tommorow. Also checked the battery's water levels and found them decently low, about 1/8th of an inch from the positive and negative busses, and about 1/4 inch or so from the top of the plates. Probably going to add some water tommoorow and see if itll resolve the problem.
Could a low electrolyte level cause this? I am ready to point fingers at a loose/ partially burnt fusible link, low water level, or a ground out in a cell on my cheapo johnson controls battery.
The most interesting thing happened to me today, I stopped pretty hard to stay away from a few doe and fawn in the road, while traveling downhill. At the end of the stop I didnt reduce braking pressure too much so there was a abrupt stop and the engine hiccuped. Thought nothing of it and continued on my way, until I stopped downtown. A half abrupt stop at a stop light and the engine shut off. This was driving with the headlights on, fan on speed 1 or 2. I checked the connection from the fusible link to the battery post, will check quick connect tommorow. Also checked the battery's water levels and found them decently low, about 1/8th of an inch from the positive and negative busses, and about 1/4 inch or so from the top of the plates. Probably going to add some water tommoorow and see if itll resolve the problem.
Could a low electrolyte level cause this? I am ready to point fingers at a loose/ partially burnt fusible link, low water level, or a ground out in a cell on my cheapo johnson controls battery.
'83 maxima sedan, l24e, a/t, black
227K SOLD 6/7/2012
227K SOLD 6/7/2012
- asavage
- Site Admin
- Posts: 5431
- Joined: 18 years ago
- Location: Oak Harbor, Wash.
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Distilled water only in batteries. Not "Spring" water nor "Drinking" water. Distilled.kassim503 wrote:Probably going to add some water tommoorow and see if itll resolve the problem.
No. Look elsewhere.Could a low electrolyte level cause this?
Regards,
Al S.
1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
Al S.
1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
- kassim503
- Posts: 1027
- Joined: 18 years ago
- Location: Stony Brook, NY
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- kassim503
- Posts: 1027
- Joined: 18 years ago
- Location: Stony Brook, NY
- kassim503
- Posts: 1027
- Joined: 18 years ago
- Location: Stony Brook, NY
Update, added water to battery, seems to be holding a more steady voltage, eliminated the insane voltage drop I had with turning headlights on, or operating blower.
Going to check coil power feed wires and pull the kick panels to see if I can see any change jumping around under the dash, see how it goes
Going to check coil power feed wires and pull the kick panels to see if I can see any change jumping around under the dash, see how it goes
'83 maxima sedan, l24e, a/t, black
227K SOLD 6/7/2012
227K SOLD 6/7/2012
- kassim503
- Posts: 1027
- Joined: 18 years ago
- Location: Stony Brook, NY
Upon further inspection, I noticed the ground cable was loose on the terminal. I had post type disconnect switch on the battery for when I was not driving the vehicle regularly, and the cable was loose on the end of it. Removed the disconnect and put the ground cable on its proper post. So far no problems so far, but they are really sporadic. Will update on progress at the end of the week
'83 maxima sedan, l24e, a/t, black
227K SOLD 6/7/2012
227K SOLD 6/7/2012
- asavage
- Site Admin
- Posts: 5431
- Joined: 18 years ago
- Location: Oak Harbor, Wash.
- Contact:
- kassim503
- Posts: 1027
- Joined: 18 years ago
- Location: Stony Brook, NY
The problem appeared to just be a loose ground, so far I have not had any stalling or power loss problems associated with idling, stopping, or the blower.
I should of inspected the ground a bit better, and I would of saved myself the minimal hassle involved with this. Good thing it was nothing more severe
I should of inspected the ground a bit better, and I would of saved myself the minimal hassle involved with this. Good thing it was nothing more severe
'83 maxima sedan, l24e, a/t, black
227K SOLD 6/7/2012
227K SOLD 6/7/2012
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