Late-Bay Blower Motor Stopped Working

Manfred · Post by **Manfred** » Mon Apr 27, 2009 9:16 am

The blower motor in my late bay has quit working. It was one of the first things I fixed, thinking it would fix my heating problem. All the blower required was a change in a couple of fuses and checked the connections and it came right on.

Yesterday, after finding a huge heat ducting rip near the front of the bus, I went to throw on the blower, and it's not working. I replaced the fuses and checked the wiring as I did before and no joy.

I hear a click at the rear of the bus when I turn blower on. I'm thinking it's the switch. I'm guessing if the switch is working, the blower is dead. Any thoughts on the subject?

dtrumbo · Post by **dtrumbo** » Mon Apr 27, 2009 10:09 am

Manfred wrote:I hear a click at the rear of the bus when I turn blower on. I'm thinking it's the switch. I'm guessing if the switch is working, the blower is dead. Any thoughts on the subject?

The clicking would be the relay (which is an electrically actuated switch). If the relay is clicking, it is most likely working correctly. Now you need to check to see if power is getting to the relay. The power comes from a connection on the starter (yeah, really) to an inline fuse (which should be a red 16 amp) to the relay. If you don't have one, get a cheap multi-meter from your local hardware store and measure the DC volts going to the relay (terminal M) and then see if it's getting to the output of the relay (terminal B & J, huh, huh!)

If that's all good, yer motor's shot. You can get yerself and brand spanky-new one here.

http://germansupply.com/home/customer/p ... at=&page=1

Or you can e-mail Ken at www.thebusco.com and see if he has a used one. For the reasonable price Scott charges, I recommend new over used in this case.

Let us know what you find.

Post by **Amskeptic** » Mon Apr 27, 2009 7:58 pm

Manfred wrote:The blower motor in my late bay has quit working.

What year is your bus? Pre-'76, they were signaled by the alternator.

Just found out it is a '78. So dtrumbo, if the earlier buses give the relay coil juice from the alternator and ground the circuit at the dashboard to connect the red wire from the starter to the blower itself, how do the late bays provide juice to the relay coil?
10 pts
Colin

dtrumbo · Post by **dtrumbo** » Tue Apr 28, 2009 5:16 am

Amskeptic wrote:So dtrumbo, if the earlier buses give the relay coil juice from the alternator and ground the circuit at the dashboard to connect the red wire from the starter to the blower itself, how do the late bays provide juice to the relay coil?
10 pts
Colin

The heater blower relay coil gets power from terminal 15 on the ignition coil which is energized by the 'on' position of the ignition switch.

This is why in winter, when I always leave the red heater lever down and I turn the key on my bus to 'on' to check the generator (alternator) and oil pressure warning lights prior to starting, I hear the heater blower come on.

I assumed since Manfred said he heard what we think to be the relay clicking on and off with the heater lever (switch), that all was well with this part of the circuit. I suppose I shouldn't assume and we should revisit the entire system to make sure all is right.

What do I get with my ten points?

Post by **Amskeptic** » Tue Apr 28, 2009 8:09 am

dtrumbo wrote:
The heater blower relay coil gets power from terminal 15 on the ignition coil This is why in winter, when I always leave the red heater lever down and I turn the key on my bus to 'on' to check the generator (alternator) and oil pressure warning lights prior to starting, I hear the heater blower come on.

Correct. And why we earlier buses only hear it kick on after the engine is started and the alternator is putting out. So our power supply to the relay coil comes from the little blue wire coming out of the regulator.

dtrumbo wrote:
I assumed since Manfred said he heard what we think to be the relay clicking on and off with the heater lever (switch), that all was well with this part of the circuit. I suppose I shouldn't assume and we should revisit the entire system to make sure all is right.

You were spot-on with your advice. I just needed to fill in the earlier Type 4 bus crowd that they have to wait until the alternator has kicked in before they can test the heater blower.

dtrumbo wrote:
What do I get with my ten points?

You get the satisfaction of having ten points.
Be sure to report it on your 1099 MISC

Manfred · Post by **Manfred** » Wed Apr 29, 2009 9:52 am

Thanks guys. When I first got the blower working, it would kick on without the engine running.

Post by **Amskeptic** » Wed Apr 29, 2009 4:58 pm

Manfred wrote:Thanks guys. When I first got the blower working, it would kick on without the engine running.

That's cuz you're late . . . late model.

Manfred · Post by **Manfred** » Mon Jun 29, 2009 12:43 pm

I figured out why the blower was working.

I pulled out my sink and stove this weekend. It looked horrible. PO had repainted it green and painted mushrooms all over it. I don't think I would ever use it. And I was right to think none of it was working. The wiring was a horror show.

After I finished, Amongst all the rubble was the cut end to my red wire that runs to the #7 seven fuse to my blower motor. The cut end was completely corroded. I have no idea how it was even working in the first place.

Post by **Amskeptic** » Mon Jun 29, 2009 1:53 pm

Manfred wrote:I figured out why the blower was working.

I pulled out my sink and stove this weekend. It looked horrible. PO had repainted it green and painted mushrooms all over it. I don't think I would ever use it. And I was right to think none of it was working. The wiring was a horror show.

After I finished, Amongst all the rubble was the cut end to my red wire that runs to the #7 seven fuse to my blower motor. The cut end was completely corroded. I have no idea how it was even working in the first place.

What on Earth blower are we really talking about here?????

The HEATER Blower we were assuming is mounted in the engine compartment on the ceiling and gets electricity from the starter solenoid and has an inline fuse dangling near the blower. Whatever blower you are discussing that gets power from the #7 accessory fuse spot . . . is it a PO install or something?
Colin

Manfred · Post by **Manfred** » Mon Jun 29, 2009 2:12 pm

Amskeptic wrote:
What on Earth blower are we really talking about here?????

The HEATER Blower we were assuming is mounted in the engine compartment on the ceiling and gets electricity from the starter solenoid and has an inline fuse dangling near the blower. Whatever blower you are discussing that gets power from the #7 accessory fuse spot . . . is it a PO install or something?
Colin

Yes, the heater blower motor that hangs above the engine. This is for a '78 FI. I have a red wire that hooks up to my fuse box that some how connects to my blower motor. I thought I figured it out by reading the wiring diagram. It's a red wire that has two inline fuses on it and runs to my fuse box (7). Atwell's site says the 9, 15 amp fuse is my accessory fuse. 7 is my fan fuse.

When I first got the bus, the fan was completely disconnected. I remounted it. I looked over the wiring diagram and found the blower wire went to the 7 fuse. I found a wire near the front of the cab that fit the description the wiring diagram gave and plugged it into my 7 fuse and low and behold the blower came on.

Oh FYI the Bentley diagram doesn't say there are two inline fuses connected to the fan wire, but the Haynes manual does. There is one near fuse box end of the wire and as you know, there is one near the fan.

dtrumbo · Post by **dtrumbo** » Mon Jun 29, 2009 3:45 pm

Manfred wrote:I looked over the wiring diagram and found the blower wire went to the 7 fuse.

Perhaps you're confusing your heater blower motor with the accessory fan blowers that mount up in the cab. These were commonly called "ambulance fans".

Click on this for full-screen.

The ambulance fans (V2 on the above diagram) DO connect to fuse #7 via a dash-mounted switch. I don't think this is what you have. As Colin described, the heater blower motor (V4 on the above diagram) is powered by a relay (mounted very near the blower) that gets it's power via a red wire from the starter solenoid. This red wire does have one inline fuse (S25) and it too is located very near the relay. The relay is energized by pulling the heat lever (right red lever) all the way down. This actuates a micro-switch that provides a ground connection to the relay turning it on and thusly, your blower motor.

The #7 fuse is usually vacant as the ambulance fan option, as far as I know, was pretty rare. That's why it makes a great choice to power other accessories (stereo, etc.).

Manfred · Post by **Manfred** » Tue Jun 30, 2009 5:10 am

dtrumbo wrote:
The ambulance fans (V2 on the above diagram) DO connect to fuse #7 via a dash-mounted switch. I don't think this is what you have. As Colin described, the heater blower motor (V4 on the above diagram) is powered by a relay (mounted very near the blower) that gets it's power via a red wire from the starter solenoid. This red wire does have one inline fuse (S25) and it too is located very near the relay. The relay is energized by pulling the heat lever (right red lever) all the way down. This actuates a micro-switch that provides a ground connection to the relay turning it on and thusly, your blower motor.

The #7 fuse is usually vacant as the ambulance fan option, as far as I know, was pretty rare. That's why it makes a great choice to power other accessories (stereo, etc.).

I see. Hmmmm now I'm really scratching my head. WTF is this long red wire that leads up to my fuse box? It must have powered something for my stove/sink deal, but why did my heater blower turn on when I connected this thing? Was it a coincidence the blower turned on when I hooked this wire up? Such strange goings on. Well, it makes sense now that when I messed with this strange red wire, the blower motor doesn't come one. To be continued....

dtrumbo · Post by **dtrumbo** » Tue Jun 30, 2009 5:19 am

Manfred wrote:Such strange goings on. To be continued....

With two of the three VW's I own, I've spent a substantial amount of time putting the electrical system back to its original state. Previous owners can be evil either by malice or ignorance. Keep at it, fix one thing at a time and you'll get there!

Manfred · Post by **Manfred** » Tue Jun 30, 2009 5:29 am

dtrumbo wrote:With two of the three VW's I own, I've spent a substantial amount of time putting the electrical system back to its original state. Previous owners can be evil either by malice or ignorance. Keep at it, fix one thing at a time and you'll get there!

I have a feeling I should just plan on rewiring the entire bus. A lot of wires are getting brittle. Might be my winter project. On the bright side, I can get rid of this annoying red wire.

RussellK · Post by **RussellK** » Thu Jul 16, 2009 12:57 pm

Doesn't that red wire run the pump for the sink?

Itinerant Air-Cooled

Itinerant Air-Cooled

Late-Bay Blower Motor Stopped Working

Late-Bay Blower Motor Stopped Working

Re: Late-Bay Blower Motor Stopped Working

Re: Late-Bay Blower Motor Stopped Working

Re: Late-Bay Blower Motor Stopped Working

Re: Late-Bay Blower Motor Stopped Working