Yes, what you want to do is see if there is current running to the blower motor.

to test find the two electrical wires going to the fan moter. One is a ground, black and the other the positive (hot) wire.

Pull the connectors apart for the hot wire, and using a test light connect one end to the hot wire and the other to a ground (steel of the dash etc.) the test light should light if there is current being sent to the motor. (don't connect to the wires attached to the motor as they don't have current once you have disconnected them from the current)

If you don't have a test light get one it is a very valuable tool.

You of course must have the ignition switch turned on.

Have you checked all the fuses already?

Edited May 19, 201014 yr by ZCCOR#109

@ZCCOR : I have checked all the fuses allready and they are all in good condition. (In fact, I replaced them all with brand new fuses a few weeks ago.)

I do not have a light tester but I do have a voltage checker, that has the red and black wires and gives off a numerical reading. I'm guessing that this will work for what I am going to be doing.

If there is a reading coming off the HOT wire to the blower motor, what's the next step for testing the fan knob on my dash? I hope it doesn't require me to tear apart my dash to test . . . I seriously don't want to go that far, but If its required then its required haha.

Edited May 19, 201014 yr by New-to-240z

What you are doing is a process of elimination.

The blower SHOULD work if there is electical power to it.

The switch, that has three positions, sends various amounts of power to the motor which allows it to turn at various speeds.

So, if you check the wire going to the motor, and there is no power, then either the switch or fuse are not allowing power to flow. (Also, the ignition switch has to be on to allow power to the three position fan switch of course.)

New fuses can have manufacturing defects and blow early in their life when new so check them again.

If you are getting electric current to your test equipment with the fan switch on to one of its on positions, then the motor is not responding to that current. Deduction is the motor is broken.

You can further test by making a test wire of considerable length and run straight from the battery or another hot wire to the blower motor and see if it runs. A final test is to include a separate wire for the ground in the remote possibility that it is broken and is not grounding the motor to close the circuit.

if there is no current going to the motor with the fan switch on, then the switch is bad, or the wire is broken. But a broken wire is a very remote situration. If the power wire insulation gets frayed and "grounds out" then the fuse will blow and that is another task to identify where the wire failure is and replace. Can't imagine this situation unless someone has been working under the dash cuting wires, etc. etc.

good luck

The fuse to the blower motor on a 240Z is not in the fuse box. It is in an in-line fuse holder buried in the wiring harness under the dash.

When I bought my car someone had disassembled the dash for unknown reasons, and removed and replaced the fan switch. In messing around putting things back together I discovered the in-line fuse holder, opened it up, and saw that the fuse was blown. I stuck a new fuse in it and voila! The fan she is working!

Well, I'll be digging under there tonight. Hopefully I can find something that looks like an inline fuse! Its not hot yet, and to tell you the truth my Z will probably not see the road for at least 2 more months, but ya . . . Its nice to know it will have airflow when I need it.

I think mine was a light blue wire with a skinny white fuse holder. There were a pair of them, one goes to who knows what and the other the blower. Both were on blue wires

Can anyone validate that it is a blue wire? I think I may have already found the wire and inline fuse earlier. Also, what's the rating on the fuse?

It's a blue wire with a White'ish clear inline fuse-holder. I think the fuse is a 10 or 15 amp. Start with the 10. if it blows over time, then go to the 15. Always best to start low and protect the circuit.

Dave

Z's : Hey man! I was wondering if you still do the turn signal switch rebuild? I am starting to notice my turn signal is not contacting anymore and I have to hold it down in order for it to work

Also, I will look into the wire tonight. Hopefully I can finally get this damn blower blowing.

Edited May 20, 201014 yr by New-to-240z

Yup, I still do the service. My email is below, in the signature.

Well I looked at the fuse and it is fine. I tested the red wire into the motor and it had no power running to it at all when I had the car on and the knob turned to HIGH. (or any setting for that matter.) I was wondering if there was some way of me being able to rig a new switch that ran from the battery to the motor. Could I just get some normal switch from an auto parts store that I could run in-line with the motor that would allow me to bypass the stock knob (since its a PIA to remove the center console and all the wires and so forth.) ?

anyone?