wire running from beneath A/C box back to junction?

[Flye]

67 442 with A/C

I don't know if this was cobbled, or the way it was supposed to be, but trying to get the chopped up engine harness straightened out.

There was a wire that was running from the junction box to a EDIT>: relay as part of a 3 wire connector. This wire has a fuse holder in.

I checked it to provide the hot for the entire system evidently. I edited this initial post as I misled others that followed in that I had the wire going elsewhere.

I'll do a separate posting on the 'A/C harness', and whether there is anything separate.

[Yellowstatue]

There should be a relay mounted above the a/c case straight back from the resistor block and that wire should plug into it. The high speed blower is a separate pwr feed with separate fuse...

[Lady72nRob71]

If you have rear defogger, then there will be another fuse holder also.
See here:


Of course this is on my '72 but the wiring I think is similar but relays could be in different places.

[tim72]

Originally Posted by Lady72nRob71

If you have rear defogger, then there will be another fuse holder also.
See here:
Rob,
On the far left of the picture there is a junction box. What is this used for ? I see on my car which is also a 72 that there is a hole for this box. Of course I do not have anything there at the moment as I had no idea what went there. lol!!!

Would you read my post in electrcal about my positive cable problems since you have a 72? Maybe you have an answer for my problem or could help. It would under batery cable tim72.

Thanks
Tim


Of course this is on my '72 but the wiring I think is similar but relays could be in different places.

[tim72]

Originally Posted by Yellowstatue

There should be a relay mounted above the a/c case straight back from the resistor block and that wire should plug into it. The high speed blower is a separate pwr feed with separate fuse...

I have no power going to my blowe fan. I cannot track it down. The fuse seems fine. Sometimes it works sometimes it doesn't. Any sugestions on where to start looking?

Tim72

[Lady72nRob71]

Originally Posted by tim72

I have no power going to my blowe fan. I cannot track it down. The fuse seems fine. Sometimes it works sometimes it doesn't. Any sugestions on where to start looking?

Tim72

Tim, so high speed does not work and the other speeds do? If so, the high speed relay could be bad, OR the wiring itself. In the picture above, that mulispliced wire on my air cleaner had been "fixed" several times due to excessive current through weakened wire. Check for opens near the fuse holder or at the connection terminals. Turn on blower and wiggle the wires. If it starts comning on, look for wire smoking, or feel for hot areas or even watch for sparks. That blower pulls 20-25 amps on high!

[Flye]

Not sure this is a great way to chase a wire, but when I took the wire (in initial question) off, and turned fan switch on, I got a loud click off what I assume is a relay under hood, but no fan speed.

Put the wire back to the Junction box and the fan runs on high speed in the high speed setting.

As I had posted earlier in separate posting, I have no fan speed in the low setting on the switch.

Are low speeds on fan on a separate circuit?

[Lady72nRob71]

Originally Posted by Flye

Are low speeds on fan on a separate circuit?

Yes! The voltage for lower speeds come from a fuse under the dash. It is routed through the fan switch, then through the blower resistor to the motor.

Check the fuse first, the resistor second, as it is a common failure. On my 72, the resistor is located on the heater box under the hood, right below the POA valve. Four wires connect to it.

BTW, you troubleshot it like I would have...

[Flye]

In trying to troubleshoot the relay, I discovered that i had misstated originally on the hot wire from the junction box. I edited the first post in this thread.

The wire seems to provide hot to the relay. I'm going to do separate post as I don't want to have wrong info on this one.

Thanks.