A/C not turning on even after installing new parts

I don’t doubt you have checked the fuse.
How are you checking the fuse?
If it an LED test light, try a different method.
Those things don’t always tell the truth.

Just ask @12TRDTacoma

 

https://www.youtube.com/watch?v=3GXSHRJYxTQ

 

It's true, LED test lights are a diagnostic aid, but they should be treated exactly like that, an aid. They should not be treated as be all end all in testing condemnation of parts in question, because they have been known to give false positives in the past. In order to ensure continuity is flowing through whatever fuse is in question to eliminate it beyond any shadow of doubt, a dedicated DVOM with an integrated ohmeter mode should be used.

Most of the time you can get away with testing it with something like a power probe, but when the issue involves digging and tearing deep into fuse boxes, internals and maybe even your HVAC system, you want to make sure that base is covered and 1000% known good.

 

I’m by no means “good” with electrical, but I’ve been learning. Slowly, very slowly.
I came across a video, where they were diagnosing a window issue.
There was power, and ground, every where it should be, the window motor was good.
The problem was in the switch, It had continuity, what it didn’t have was the ability to carry the current.

I see why electrical work is expensive.
Sometimes, it takes a lot for work to figure it out.

 

Electrical can be a difficult one to work on sometimes. Even myself who has been working and messing with it for years, I still get taken to school about it.

People complain all the time about pricing for electrical, but they gotta remember, you aren't paying me for what I can do, you're paying me for what I know.

 

No power on relay pin 1 nothing will happen no ground on relay pin 2 nothing will happen. If you are using a voltmeter check voltage between pin 1 and pin 2 key on any speed. It takes a pretty good short to take out a 50 amp fuse your probably talking smoke first.

 

I've been doing electrical / electronics for 47 years and I learn something daily....

 

I got 16 years of automotive under my belt, but truthfully probably like 11 or 12 of electrical.

 

Everything goes along fine until you let the smoke out.

 

Plumbers make more. And they can keep it. I deal with enough shit as an electrician. I don't want to deal with it literally.

 

Sorry for not getting back to this topic sooner, was in the process of moving and buying and selling a home.

The 50 amp fuse in position 2 in the above picture will blow as soon as the motor starts to rotate, it will not blow until connected to the fan motor. I did get the fuse block to separate and found no shorts or issues of any kind in there. If you all can continue to help me troubleshoot this I would appreciate it.

Thanks

 

Does the 10A A/C fuse blow also?
Does either one blow with the resistor hooked up?

 

If the 10 Amp A/C fuse also blew then the problem is in the A/C Amplifier circuit.

If the 10 Amp A/C fuse did not blow then you have a problem with the Blower Motor, Resistor, Blower motor switch or the associated wiring.

 

The 10a Fuse doesn't blow, I did get a new blower motor so it isn't that. I checked out all the wiring from the blower motor back to the firewall and see no problems. Next move will probably be the resistor, where is the blower motor switch located?

 

The blower motor switch is in the control panel in the dash, left hand knob for motor speed.

How are you checking the wires? You probably need a Digital Multimeter to do a good check. Look for grounds and short circuits.

From your above post it indicates that the 50 amp fuse doesn't blow when the motor is disconnected.

Is this true?

That would indicate that the blower motor is the issue.

Then you say you replaced the motor and it still blows the 50 ampere fuse.

 

Correct, with the blower motor not connected nothing blows, turn off everything and connect the blower motor, turn the key and the blower moves just a little bit and then the 50 amp blows.

 

I assume when you disconnected the blower you are disconnecting the two wire plug on the motor correct?

Now try this. Unplug the resistor 4 wire connector and leave it disconnected.

Turn on the truck and try and run the fan on high setting. Note: The lower settings don't work with the resistor disconnected.

Did it blow a fuse this time?

If the fuse blew again the issue is the Blower Motor.

If the fuse did not blow the issue is the resistor assembly.

 

I will give that a try this week and report back, thanks.

 

The plug for the blower motor apparently got warm and the connectors were loose so I ordered a new plug, once it comes in I will be testing to see if the resistor is faulty.

Thanks again.