A friend has a '95 Suburban with the dual vents. (Front and rear.) The rear fan works fine, but the forward motor is goofy. Whether you use the defroster vent or heater, the past few weeks the fan can take 20 - 30 minutes to actually start working. If it decides to work at all.
When adjusting from off to high, you can hear the faintest attempt at working from it for about 3 nanoseconds, then silence. The motor does work, but for some reason it just doesn’t want to kick in right away.
Any ideas what we should look at first? There aren’t any other problems with the truck electrically or otherwise.
Start with the easiet thing, pull the wiring harness off the motor and check for voltage. No voltage, then you have to start wire tracing. Most likely it has voltage and it’s one of two things (well three actually). Either the resistor, depending on where the resistor is, or the motor itself. On a '95 truck, I’m going to guess these are both located under the hood and more or less easy to access and test, if your comfortable working with cars anyways, and probably not to expensive either. If I had to guess off the top of my head, maybe $40 for the resistor card and $60 for the motor. Since I don’t know the exact setup of your car it’s hard for me to tell you the easiest way to tell which part it is, but if you’re handy with a multimeter it’s just a matter of testing.
Well, I couldn’t find any pictures or component locations for your truck at Autozone, but I’m sure we’ll have some mechanics dropping by soon enough.
In the mean time, the first thing you need to do is check the voltage at the motor, assuming you get voltage (since you hear it trying), I’m going to guess you just need to drop a new motor in.
I agree, the most likely cause is a faulty blower motor, but as mentioned it would be wise to check for good power and ground to the motor before replacing it.