feldy3 Posted January 7, 2016 Share Posted January 7, 2016 Hi all, I've got a question: My heat works, but intermittently. Also, the strength of the blower seems to go up and down, mostly when I accelerate and let off the gas. Right now, if I turned off the heater for a minute or two, the heat will come back on, but the blower fluctuates on power. I feel that I may have two problems: heater core and blower, or maybe it is just the alternator? Any help would be great!, Thanks. Link to comment Share on other sites More sharing options...
SpecialWarr Posted January 7, 2016 Share Posted January 7, 2016 I would suggest you remove and clean the blower motor housing around the fan, it comes off with a couple of screws. There is a how-to ( I think) in the Garage header section. The power fluctuation might be trees leaves and stuff slowing the motor or the resistors starting to overheat. Either way, clean that thing out and take a look around for other issues! 1 Link to comment Share on other sites More sharing options...
feldy3 Posted January 7, 2016 Author Share Posted January 7, 2016 Thanks! I just cleaned it out when I bought it in September. I did notice it was an aftermarket blower, so maybe I'll replace it with the OEM one i have from my spare parts collection, then move on to diagnose the other problem(s). Link to comment Share on other sites More sharing options...
JackStraw1 Posted January 7, 2016 Share Posted January 7, 2016 (edited) Do all of the fan motor settings work ? Is there a little heat coming out of the vents with the blower off and the temp setting all the way to the right? Edited January 7, 2016 by JackStraw1 1 Link to comment Share on other sites More sharing options...
feldy3 Posted January 7, 2016 Author Share Posted January 7, 2016 Yes, all the fan motor settings work. Haven't checked about heat when blower is off though. I talked to someone that said there could be some air bubbles in the coolant, and that is why the fluctuation between hot and cold. He said to flush the coolant and refill. Does that make sense to anyone? Link to comment Share on other sites More sharing options...
SpecialWarr Posted January 8, 2016 Share Posted January 8, 2016 some air bubbles in the coolant Yep, I guess I should have thought of that as well seeing as I do much of the flush and refill at work.... suspension though! 1 Link to comment Share on other sites More sharing options...
Slartibartfast Posted January 8, 2016 Share Posted January 8, 2016 There's a bleed screw on the intake for getting rid of air trapped in the cooling system. Bubbles in the coolant shouldn't change the speed of the blower. The fan runs off a brushed DC motor, and when brushes wear out, motors do strange things. Dry or worn bushings can cause issues as well. Probably easiest to just swap it for your spare and see if the issue goes away. I'm not sure what to make of vehicle acceleration changing the blower speed. Do the headlights or dash lights fluctuate at the same time? If you suspect the alternator is flaking out, check across the battery with a voltmeter to see if the voltage is doing weird things. Link to comment Share on other sites More sharing options...
feldy3 Posted January 8, 2016 Author Share Posted January 8, 2016 There's a bleed screw on the intake for getting rid of air trapped in the cooling system. Bubbles in the coolant shouldn't change the speed of the blower. I'm not sure what to make of vehicle acceleration changing the blower speed. Do the headlights or dash lights fluctuate at the same time? If you suspect the alternator is flaking out, check across the battery with a voltmeter to see if the voltage is doing weird things. Which bleed screw? The high or the low? And what will I be listening for? Headlights, dash, radio do not fluctuate. I'll swap out the blower, the alternator isn't fluctuating. Link to comment Share on other sites More sharing options...
adamzan Posted January 8, 2016 Share Posted January 8, 2016 I would start with a new thermostat and a coolant drain/fill/bleed. Get the 180F thermo instead of the 170. Will make a difference in your heat. Link to comment Share on other sites More sharing options...
Slartibartfast Posted January 9, 2016 Share Posted January 9, 2016 It's on the top of the intake, back by the idle air controls. Look for a little 10mm bolt with a sticker by it that says do not remove when hot. Remove that bolt (with the engine cold of course), gently squeeze the upper rad hose until coolant starts coming out of that hole, then keep holding the hose to keep from sucking air back in until you have the bolt snugged down. Link to comment Share on other sites More sharing options...
feldy3 Posted January 12, 2016 Author Share Posted January 12, 2016 Topped off the coolant and the heat fluctuation problem is gone. At idle though, the fan speed fluctuates though. Going to put a multi-meter on the battery to see if the alternator is going. I'll keep you posted. Thanks for all the help! Link to comment Share on other sites More sharing options...
JackStraw1 Posted February 1, 2016 Share Posted February 1, 2016 I recently started having the same problem with the blower motor speed fluctuating intermittently and seemingly with the acceleration so today I took it apart and had a look. There was just a little debris in the housing which I cleaned out. Then I ran the blower out of the housing and laying on the floor. It still sounded a little weak. So I unplugged it to see how it would spin by hand and if there was any possibility of the bearings seizing. Here's what the plug looked like Pretty sure this is the problem and I am gonna hook on a few spade connectors and check it out tomorrow. I'd like to do the definitive repair with a pigtail connector here but have no idea what the part number is or where to find it. Can anyone help ? Link to comment Share on other sites More sharing options...
Slartibartfast Posted February 2, 2016 Share Posted February 2, 2016 That looks like it got warm. No idea on the connector, checked at the parts store when I was there today and they didn't have one (if it's not a Chevy connector they don't have it pretty much). You might be able to dig the spade connectors out and re-use the plastic bit with new connectors. Could get it the whole plug from a part out or a wrecking yard. Looks about the same as the connectors for the washer pumps actually. You might also want to test the fan directly off 12v to make sure it's good, and check its connectors where the plug goes to make sure they're not the problem. The plug end doesn't look too corroded inside, but the connection between the wire and the spade could be bad. These fan motors are actually pretty easy to take apart, and not too bad to put back if you're careful with the brushes. I took mine apart and blew out a bunch of brush dust the last time I cleaned the heater box. Easy to oil up the bushings while you're at it. Don't do it over a surface you care about, though, that dust gets everywhere. Link to comment Share on other sites More sharing options...
adamzan Posted February 2, 2016 Share Posted February 2, 2016 Mine looks the same. Blower was actually bad. It started with fluctuating speed. But then you had to hit it to make it work. And then you get no heat eventually. Link to comment Share on other sites More sharing options...
ahardb0dy Posted February 2, 2016 Share Posted February 2, 2016 I took the motor apart on my former 94 pathfinder, just cleaned the copper windings and inside the housing and put it back together, it ran a lot better. Also clean the plastic blower wheel as dirt and crud will cause it to not spin true Link to comment Share on other sites More sharing options...
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