Heater blower blows fuses... Why?

[ZSaint]

I have completed my resto and only 2 items do not work. My heater blower and my power antenne. They both worked before I disassembled the '71 240Z. When I turn the key on, the blower fuse blows. It is a separate fuze for the blower motor. Why does the blower have a separate fuze? I cannot find the power for the antennae. Do you think I somehow got these fuzes/wires mixed up? I looked at the wires and it is the only wire that connects to the fuze. Anyone have any ideas?

[montoya_fan01]

Sounds like a short in the wiring, or one in the blower motor. Something is drawing more power (amps) than the blower motor fuse can handle.

Is the antenna blowing a fuse? If not, do you know if it is even getting power through the wiring harness TO the antenna itself?

Why does the blower motor have a separate fuse? Probably because it draws enough power on it's own that it cannot share a fuse with something else.

Time to break out the volt/ohm meter and do some troubleshooting.

[ZSaint]

Could I have bolted the blower assy in the dash and "crimped" one of the wires going to the blower motor? It sounds like this wire is grounded. It flashes pretty good when I turn blower on. She is grounded somewhere. The Z is at a friends shop right now having an exhaust system built for it. As soon as it is done I can start the car. I can take it to the auto electric place and have them look at it. I can spend days fighting these electrics. I want to drive my newly restored Z!

[EScanlon]

You might also check the wires going to the resistor coil at the exit of the blower fan. The blue wire you see in the bundle going to the blower motor is for the air conditioning portion of the harness. If you don't have A/C then you don't need that wire. Just tape it off.

Enrique

[ZSaint]

OK, blue wire going to the blower motor. I did not know that '71 had A/C. I thought I had some wiring for the A/C but I was told by "an expert" that '71 Z's did not have wiring for A/C. Hmmm?

[EScanlon]

Possibly the Early 71's, I'll have to check.

But if you look at the 71-72 Wiring Schematic, look at the wire that is between the Reverse Switch and the Turn Signal Flasher. That powers the blower and also leads to the connection for the wire below that...AIR COND POWER.

Enrique

[ZSaint]

I know. I guess they had the schematic for the A/C wiring. I have my exhaust 2/3 done. Using 2 1/2" pipe with manderal bends. All we have left to do it the pipe from the header to the straight tunnel pipe. Got late last night so we will get it done today. I will check out the wiring and the schematic. I believe this wire is two different colors. I think it is red and black. Sound kinda funny but that is the way it went together. Probably is wrong, don't you think? I guess if it keeps blowing fuses, it must be wrong. I'll let you know....