I'm new to the forum, so I'm probably gonna sound very stupid, but that's ok with me!

I've read quite a few threads on this subject and came across the resistor, fuses, and relays.

I have some fundamental testing procedure questions.
I'm an Appliance tech, so I know how to use a meter, but Dumb question number.....

1. To test the resistor, it says to back probe the brown/orange wire to check for voltage. So I'm assuming I would hook up my positive lead, here?
Do I really need to hook up the black lead all the way to the negative terminal on the battery? Just with a long extension? Or is there somewhere else I can hook the black lead to? (I know, how dumb!)

2. I downloaded owners manual, but I can't seem to find a fuse or relay specifically for the blower, so what fuse and what relay is it?

3. In the Haynes manual, it says locate the blower motor relay, in the relay box under the center dash panel, where the hell is that?

4. Do I need to remove the glove box to access the resistor and blower hosting (shoulda been my first question I guess)

5. Anything else I should know?

 

Quick way of testing is to turn your blower on all speeds. If it works on no low speeds but it works on high then most likely your resistor is bad. If it doesnt work at any speed then theres a few things it could be. Could be a fuse, could be a bad blower motor, could be the blower switch.

Theres no reason to really back probe these wires to check for voltage, if you have no blower on any speed then that means you are either not getting power from the switch or two the switch or you have a bad blower. if you get high speed but no slow speeds then it is your blower resistor. Theres a slim possibility that if you have automatic climiate control that it could be a climate control module malfunction. Ive had one I worked on at work that the head unit was malfunctioning and it prevented the blower from working on any speed but high.

 

Thanks for quick reply.
It doesn't blow at all,
So I'm hoping for a bad fuse or relay, worst case bad motor.
Although, for the longest time, there would be no speed difference between position 2 and 3, so low would be low, 2 & 3 medium, and hi would be high, so I don't know if that would be an indication of a bad resistor.

So now that you know the blower isn't working at all, what would be the next step?
Again, how do I locate the fuses and relay for the blower?
Thanks again.

 

I would take and unplug the harness connector at the blower itself. I would then find out which wire is ground and which one is hot. I would then use either a test light or a volt meter to see if power is coming to the harness. If you have power at the harness at the blower motor then the blower motor is dead.

Personally I would pull the fuse box cover and see if the blower motor uses a fuse or a relay. if its a fuse check it, if its a relay see which other relay is the same and just unplug the blower and set it to the side and plug in the duplicate relay you unpluged from another circuit. Then turn key on and see if it works, if it works then your relay is bad. If this checks out good then I would move to checking for power at the blower motor. If there is power there I would check ground to make sure theres a ground and its not bad but typically they dont go bad on a newer vehicle, I typically avoid this unless the vehicle has a known problem with the ground side.

I cant say on this truck as I didnt check into it on identifix to see what the most common is for a non working blower motor.

 

I finally got around to checking it out, i took the wire harness off directly from the motor an checked for power at the plug, with the key on, i didnt get any reading when i hooked both leads directly to it, then i tried each wire of the plug to ground, i didnt know if i was doing it right since i wasnt getting a reading either way i checked it.
So i plugged it back into the motor and it started blowing. So i go to start the truck up and it quits blowing, so i go fiddle with the connector and it starts again, after a minute of being on the motor smelt burnt and it would fluctuate speeds, so im assuming the motor is bad and have one coming tomorrow, ill install and see how it goes, but im pretty sure its just the motor.
Thanks again!

 

How did the connector look? You might have to get a new pigtail and replace the connector.

 

I was thinking that too, it looked ok to me, i didnt see any burn marks, the contacts looked good.
There is another harness that the power wires to the blower motor stem off of, and there is a burnt connector on that one, but i have no idea what that supplies??

 

Replaced blower motor, back in biz.. Thanks!

 

I've got a 1999 Ford E250 and the blower just stopped one day after 5 years of no issues. So, being the shade tree mechanic that I am I try to fix this myself. well, after replacing the resistor, the blower motor itself, the fan speed switch on the dash and checked the relay/fuses and I still have no fan. Any suggestions on where to go from here. I would appreciate any help thanks. oh the heater is working I can feel the heat coming through while moving and here the sound of it changing from defrost to floor and vent etc. just no blower motor