Heater troubleshooting

I rebuilt my heater box and I installed it today. However when I hooked it up and turned the fan switch on it wouldn't start. The blower fan is grounded correctly.I took a jumper wire and ran 12 volts to the fan and the fan turns on. I tested the plug that goes to the heaterbox from the switch with a test light and didn't have any power.I tried following the fan switch wires but they lead under the dash Im guessing to the Fan On/Off switch. I unscrewed the heater control from the dash and it seems like the Fan switch is connected.The previous owner didnt have the heater working so I have no idea on how the system works.Does anyone know what the issue might be?

 

How's the fan resistor?

 

Is that located on the bottom of the heater box where the plug connects to?

 

You did check the fuse...right?

 

Yeah fuse is ok

 

is this an...A/C...car?

 

No A/c..73 no ac

 

I double checked and all of the fuses are good..Should I check anything else?

 

the key has to be on for their to be power at the switch.
you need to check for power at the switch at this point.
if you have power to the switch then you know the problem is between the switch and the heater box.
if you dont have power then the problem is between the switch, ignition switch and fuse block

 

With key on I have no power at these wires. I'm sure they connect to the switch.



Is there any way that I can test the switch directly?

 

it looks like their is only 3 wires in that plug.
so im guessing those 3 goto the resistor block in the heater box.
their should be a power feed wire that goes to the switch.
you should be able to take your test light and check for power at the switch. you can put in on one of the posts that plug goes to and then move the switch to different positions and see if any have power.

by the way hows the 5 speed?

 

didnt your car have an aftermarket a/c system removed?

 

Yea those 3 wires plug into the heater box.So test them where they connect to behind the switch?And yes my car has an aftermarket ac disconnected.
And the T5 is awesome I still need to practice on mastering the hills but I got it down.How was your vacation?

 

my vaca was great. very relaxing.
take your test light over to the fan switch by the head light switch and see if their is power there when the key is on.
also i think there was a fan switch in the old ac vent in the center of your dash. the problem may be that switch is part of the system now.

 

Today I gave it another shot at troubleshooting the blower motor. I found out that the problem was at the fuse box. The fuse clip was very corroded. So I unbolted the fuse block, cleaned the fuse clip with sandpaper and installed a new fuse and my fan finally worked.Finally I can install my heater system and move on to the next project. :bananaman