My blower seems to work whenever it wants?

When I first got the truck it worked once. Turn it to anything on the right dial (feet, defrost..etC) and it would sometimes work. I could use the fan switch speed slector and it would work on 1-4 position. A couple days later and nothing.. No matter where I would turn the fan selector no air was coming out..

I was also having other problems.. leaking heater control valve..etc.

I replaced the heater control valve, and I replaced the blower motor resistor, as the other one was all rusted and probablt done.

My heater worked for 2 weeks non stop.. no matter what fan position and no matter what temperature.... now I go to turn it on tonight and nothing.. the fan doesn't turn on at all.

Can anyone help me on this? What could be causing this?
I just replaced all the relays with brand new ones thinking that was a problem... which actually fix an unrelated problem of my windshield pump not working but now it does..lol

But as far as the blower, when it works I get hot and cold air depending on where I turn the middle dial.... But the problem is it not turning on....

I don't want to start replacing parts that don't need replacing but I don't know what do to?

Thanks,
-Nigel

 

Nigel,

It sounds like you may be experiencing two different problems. However, lets start with the fan control/blower motor electrical tests.

TEST I:

First check the following fuses: Fuse 2 (10AMP) in the dash fuse panel (with IGN in run position) & Fuse 16 (40AMP) in the PDB under hood.

Next, if the fuses check good, go back to the PDB under hood and locate relay 55 (Blower Motor Relay). Pull it out and swap it with a known good relay and see if it works. If not, replace original relay and continue working through the following steps.

Next, turn your ignition to the run position and turn the Mode Selector Control to AC or Defrost. Next, disconnect the blower motor power connector. Using a Voltmeter set to read 12V, connect the red probe to the blower motors connector terminal #2 (Pink with White strip wire) and the other probe to chassis ground. You should read 12V. If you read 12V, go to TEST II (A). If not, continue to next step.

Remove relay 55. Turn your ignition to the run position and turn the Mode Selector Control to AC or Defrost. Next using a voltmeter set to read 12V insert the red probe end into the relays socket terminal 86 (should be a Red with Orange stripe wire underneath) and the meters black probe to chassis ground. You should read12V. If so, reach back into the cab and move the Mode Selector Control to the Off Position. Recheck relay terminal 86. It should now read 0V. If this checks good turn the ignition to the off position and proceed to next step. If no power was found during this test go to TEST II (B).

(Note, if you’re having a hard time getting the probe end into the socket terminal, use a metal paper clip as an extension).

Next, with your voltmeter still set to read 12V, connect the red probe to relay socket terminal 87 (should be a Brown with Orange stripe wire underneath). You should read 12V. If not, repair wiring in PDB between Fuse 16 and relay socket 87.

Next, set your voltmeter to Ohms and probe relay socket terminal 85 (should be a solid Black wire underneath) and connect the other end to chassis ground. Should read continuity (1 ohm or less). If this checks good proceed to next step. If not, repair wiring between relay socket 85 and chassis ground.

Next, with the meter still set to Ohms, connect one probe to relay socket 30 (should be a Pink with White stripe wire underneath) and the other probe to the Blower Motor’s connector terminal #2 (Pink with White stripe wire). You should read continuity (1 ohm or less). If this checks good proceed to next step. If not, repair wiring between relay socket 30 and blower motor connector.

Next you’ll need to verify the blower motor actually works. To do this you’ll need a set of long jumper wires. One long enough to reach the battery. Another long enough to reach a known good ground. Connect the ground jumper to the motors terminal #1 (the one that the Orange with Black stripe wire would plug onto (Motor ground). Connect the other jumper to the Battery positive terminal and momentarily connect the other end to the motors terminal #2 (the one the Pink with White stripe wire plugs onto (Motor power). The Motor should run. If this checks good proceed to next step. If not, replace blower motor.

We’ll skip the blower resistor tests since you stated it was recently replaced and it wouldn’t stop the motor from running with the fan speed control set to the high speed position anyways.

Next unplug the Blower motor resistor connector. Using a Voltmeter set to Ohms, connect one probe to the blower motor resistors connector terminal #4 (the Orange with Black stripe wire) and the other probe to the blower motor connector terminal #1 (the Orange with Black stripe wire). You should read continuity (1 ohm or less). If this checks good proceed to next step. If not repair wire and or connector.

Next, remove the Selector Control Assembly from the dash. Disconnect the fan speed control wiring connector. With your meter still set to ohms (Note, you may need a long jumper wire for this test), connect one probe to the blower resistor connector terminal #4 (Orange with Black stripe wire) and the other probe to the fan speed control connector terminal #1 (Orange with Black stripe wire). You should read continuity (1 ohm or less). If not, repair wiring between blower motor resistor connector and fan speed control connector.

Next, connect meter probe to the blower resistor connector terminal #3 (Yellow with Red stripe wire) and the other probe to the fan speed control connector terminal #4 (Yellow with Red stripe wire). You should read continuity (1 ohm or less). If not, repair wiring between blower motor resistor connector and fan speed control connector.

Next, connect meter probe to the blower resistor connector terminal #1 (Light Green with White stripe wire) and the other probe to the fan speed control connector terminal #2 (Light Green with White stripe wire). You should read continuity (1 ohm or less). If not, repair wiring between blower motor resistor connector and fan speed control connector.

Next, connect meter probe to the blower resistor connector’s terminal #2 (Solid Black wire) and other to chassis ground. You should read continuity (1 ohm or less). If not, proceed to next step.

Inspect and clean ground on right hand inner fender panel by blower motor and retest.


TEST II:

(A) With the ignition still on, reconnect the blower motor connector to the motor. Next, remove the Selector Control Assembly from the dash. Disconnect the fan speed control electrical wiring connector. With voltmeter set to read 12V connect the meters black probe to chassis ground. Connect the meters red probe, in turn, to connector terminal #1 (Orange with Black stripe), #2, (Light Green with a White stripe) and #4 (Yellow with Red stripe). If you have power at these 3 terminals continue to next step. If not, repair wiring between blower motor resistor connector and fan speed control connector.

Set the meter to read ohms. Connect one probe to the fan speed control connector terminal #3 (solid black wire) and connect the other probe to chassis ground. You should read continuity (1 ohm or less). If you read continuity, return to Step I. If you read high resistance or no continuity, go to the next step.

Remove the right hand rocker side panel cover, inspect and clean chassis ground connections and retest.

(B) Remove the Selector Control Assembly from the dash. Disconnect the Mode Function Control electrical connector. Turn the ignition switch to the run position. Set your voltmeter to read 12V. Connect the red probe to connector terminal #3 (Black with Light green stripe wire) and the other probe to chassis ground. You should read 12V. If you read 12V continue to next step. If not, repair wiring between Fuse 2 and Mode Function Control Selector.

Note, you may need a long jumper wire for this test. With the meter set to Ohms, connect one probe to the Mode Function Control connector terminal #4 and the other probe to the Blower Motor Relay socket terminal #86. You should read continuity (1 ohm or less). If not, repair wiring between Mode Function Control Selector and Blower Motor Relay.

Once you have the blower motor working recheck the Mode Function Control switch operation ensuring all positions work, Def, Floor/Def, Floor, Panel/Floor, Off, Panel, AC, and Max AC. If they don’t switch between different modes there is either a vacuum leak in the system and or the Mode Function Selector Control vacuum switch is bad.
.

 

Thank you for the VERY thorough post!

I will be following this to the T on Friday when I am off from work, this gives me lots of stuff to do!!

I am sure I will have some questions so if you don't mind I will probably post here or Pm you.

Last night had the heat on to work... this morning coming back going to other job no heat...lol

-Nigel

 

NewShockerGuy,
When you did the Heater Motor Resistor Pak, did you just brush off the pwr side and plug it bak in or something else ?
If you used the same connector on the engine side of the harness there could be corrosion stil lin the connections causing problems.
What has been suggested is to cut the connector off, after marking the wires.
Clean the wire if the corrosion has made it up the wire at all.
Take a Spade Lug, correct size (?), attach to the wires, some without the plastic, solder them and clean, then add Heat Shrink the kind with the adhesive inside. Slide the spade lugs on the pins inside of the new resistor pak and then solder them if you can. Put the same heat shrink, w/adhesive) over all the connections and shrink.

 

I replaced the resistor which was all rusted: (will post pics when I get home) And then use dielectric grease on the male terminals on the resistor then plugged the connector back in.

I might have to swap the connector but it didn't appear to have hardly any corrosion in it or at least that I could see from looking at it...

Which would I need?





And why are they different prices which look tot be the same connector other than one has colored wires and the other is all black wires?

-Nigel

 

One of the reasons for the resistor pak to fail, if it actually fails, is bad connections.

Just thinking out loud, might be easier to check out the connector.

If all of your fuses are good and all of the other test points work out ok then think on the connector.

Not saying the Lugs will fix it but it sounds like a good idea, if that connector corrodes up a lot.

I hope to do it myself soon as the shop is available.

Luck with it.

 

So side question before I start diagnosising this weekend.. Does the connector give power to the resisotor to make the blower turn on? IE: If I cut the connector off would the blower ever work or is the resistor and harness only for the different settings, IE: high for the fan speed?

Sorry if that sounds dumb.

The link above which harness would work with our blower... they both look the same.. Just one is more expensive...

Thanks again,
-Nigel

 

The harness brings in the power.
What you might want to do before cutting off the connector is try jumping power from the battery to the resistor pak.
Problem I am not sure what wire does what so you will need some more info, sorry.

 

Power for High speed does not run through the resistor.
Basicly the resistor pack has three power inputs , one power output to the motor.
The dash switch selects which resistor gets power .
Main power goes to the dash switch , then out the selected lead to the resistor ,or directly to the motor in the case of high speed.

 

What amp is the relay rated at? I found the part number via 14b192-aa Rated at either 30amps or 50amps... I ordered 3 since I will replace all of them just in case.

I pulled the relay and swapped it and then it worked... I'm thinking it might be the relay.. it's odd, there is not rust or corrosion on relay legs, but just like my windshield wiper pump problem as soon as I replaced teh relay now that works 100% now where as before that only worked 1 out of 30 times I pushed the stalk in...

Getting there.!

-Nigel

 

Figured I'd update. Think I pretty much narrowed the problem down. But looking for advice.

Turned the blower on and NOTHING... decided I would start moving stuff, while the blower is in the ON position I opened the hood and moved the connector that is attached the blower and BAM started to turn on and spin no issues.

I believe it's either the plug or the blower it self...

What would be causing the plug to maybe not make contact with the contacts on the blower assembly?

I found a blower with the cut plug on ebay for about 40 bucks and thinking of getting it... but not sure if it's worth replacing if I can just wiggle the plug and it turns on... Any way of cleaning the plug and making it work now?

I tested with the test light and it comes on EVERY time when I plug it into the connector that would normally go into the blower... so that leads me to believe that there is no short in the actual plug as the light meter wouldn't light up right?

Thanks,
-Nigel

 

Apologies for resurrecting an old thread, but after reading all the preceding on problem isolation/determination, I found this one that describes my issue with a 2000 3l V6; there's power to the blower only on HIGH. I'm deducing that in this case, I should try an R/R of the resistor pack?

Thanks, Jeff

 

check the connector at the blower resistor. You my find its had a meltdown.

 

Will definitely check the connect at the resistor. As this seems to be an Achilles
heal for these trucks, when they're replaced (connector and resistor), why wouldn't we want to use a dielectric grease to minimize or prevent a recurrence?

 

I would strongly recommend packing this connector with dielectric grease.

 

I never updated my problem. I f'ing hate that.

So if I remember correctly I did the following:

Replaced the blower motor resistor since mine was pretty much shot a couple years back. I did replace the plug as well. That was all corroded.

Shortly after I still had what appeared to be a problem with the blower... I replaced the relay.... guess what it was, the BLOWER..lol

I found one on Ebay and knock on wood it has been working since.

With what you described it does sound like you need to replace your resistor. It's easy to do and should only take you 30 minutes if you know how to cut/solder/heatshrink the wires back.

-Nigel

 

I know this is an old thread but Thank You--I will be going thru this same thing with my 2011. The blower only wants to work when it's warm outside(go figure)
I replaced the relay and resistor already but it was too cold for me to do the testing listed here(-30+ wind chill) this past two weeks.
I'm going to go ahead and order the blower motor and cross my fingers. If there was anything else you did
to fix this issue could you fill me in?

 

I hope the blowe rmotor fixes your issue. Not really much to do if you've replaced all of that, which is eactly what I did years ago. I found a cheap blower motor on ebay for maybe 40 bucks or so... maybe less, I don't even remember. But with how cheap you can get items sometimes I just get things to test. This case the blower motor was the problem.

-Nigel

 

So my pigtail connector needs to be replaced and the one that I bought from advanced auto (or any after market) the wiring pre installed is different from the factory wiring how do I know which wire is which so i don't mess it up pictures attached for reference
I have a 2011 XLT 2WD 4.0 V6 145K miles all stock