1 speed blower fan (low)

[Girl und Panzer]

Thanks for the part numbers! It's all working normally with the relay I bought and thought was bad. I'm gonna source those parts just in case it fails later (def having a shop handle that nightmare) and run it with the funky connector for now

 

[sbman]

Thanks for the part numbers! It's all working normally with the relay I bought and thought was bad. I'm gonna source those parts just in case it fails later (def having a shop handle that nightmare) and run it with the funky connector for now

You can put it on high for a few minutes and feel it to see if it's getting hot. If it's not getting hot, then you should be good. If it's getting hot then you should probably deal with it before it has a chance to cause further damage.

 

[Girl und Panzer]

You can put it on high for a few minutes and feel it to see if it's getting hot. If it's not getting hot, then you should be good. If it's getting hot then you should probably deal with it before it has a chance to cause further damage.

Aye, you're right, I should check that. The good thing is the wire attached there doesn't seem melted

 

[Girl und Panzer]

You can put it on high for a few minutes and feel it to see if it's getting hot. If it's not getting hot, then you should be good. If it's getting hot then you should probably deal with it before it has a chance to cause further damage.

Sure enough, it did get hot enough to feel pretty uncomfortable to hold after about 5 or 10 minutes. What do you think could cause that?

 

[sbman]

Sure enough, it did get hot enough to feel pretty uncomfortable to hold after about 5 or 10 minutes. What do you think could cause that?

It's the bad connection. Bad connections turn energy into heat. The terminal and connector needs to be replaced so that it's a good connection that is not producing heat. Left that way it will stop working again.

 

[Girl und Panzer]

It's the bad connection. Bad connections turn energy into heat. The terminal and connector needs to be replaced so that it's a good connection that is not producing heat. Left that way it will stop working again.

Interesting, I was worried it might be be a sign of something deeper. At least that's a (relatively) easy sure fix then. Thanks for all the advice

 

[therestevethedog]

Hi all - I'm in a similar boat - same symptoms but different cause.

The blower works on low, but the rest of the controls don't change anything.

I replaced the resistor pack first. Cheap and mine was the original & crusty AF. No help.

I had an automotive electrician look at it, and he could't find the problem so he installed a switch that bypasses the resistor and relay that turns the fan on high. So at least I'm not melting in the heat...

So @sbman today I followed your troubleshooting steps on the relay.

I got 90ohms between Red/Blue and Blue/Red. Used a 9v battery to activate the switch. Got 0.1ohms between White/Black and Black/White. No continuity with the switch closed. So the actual relay appears to be good.

Then I tested jumping the pins on the harness. That's where this issue lies. When I jumper White/Black to any of the other settings (Black/Blue, Blue/Black, or Black/White) there's no change in the fan speed.

So I'm at a loss as to where to look next. Can anyone point me to the next link in the chain to test?

For reference, I drew (badly) the pinout wire colors.

 

[sbman]

If I understand correctly, you've unplugged the blower speed control relay and jumped the connections between White/Black wire and the three speed control wires (Black/White, LightBlue/Black, Black/LightBlue) one at at time and none of them made a difference, the blower only ran on low. You've also proven the blower can run on high by bypassing both the resistor and relay with a switch.

The blower will run on Low if the heater or AC is turned on, it's activated by the 'Heater Relay'. There are no other links in the chain, the power routes from the 'FL Heater Fuse' to 'Heater Relay' to the Blower to 'Blower Resistor' to ground. That's the low path. Jumping the wires on the Blower Speed Control Relay with the relay removed just moves the ground point in the blower resistor up a notch, so the resistor bleeds less power and the blower gets more power. The only possibilities are a bad connection to the blower resistor, bad connections at the blower control relay, cut or broken wires in the harness, corrosion in the wires or related terminals, etc... There are no other components to test or replace. My guess is it's bad connections or cut wires on the blower speed control relay connector and the wires leading to it.

 

[sbman]

Hi all - I'm in a similar boat - same symptoms but different cause.

The blower works on low, but the rest of the controls don't change anything.

I replaced the resistor pack first. Cheap and mine was the original & crusty AF. No help.

I had an automotive electrician look at it, and he could't find the problem so he installed a switch that bypasses the resistor and relay that turns the fan on high. So at least I'm not melting in the heat...

So @sbman today I followed your troubleshooting steps on the relay.

I got 90ohms between Red/Blue and Blue/Red. Used a 9v battery to activate the switch. Got 0.1ohms between White/Black and Black/White. No continuity with the switch closed. So the actual relay appears to be good.

Then I tested jumping the pins on the harness. That's where this issue lies. When I jumper White/Black to any of the other settings (Black/Blue, Blue/Black, or Black/White) there's no change in the fan speed.

So I'm at a loss as to where to look next. Can anyone point me to the next link in the chain to test?

For reference, I drew (badly) the pinout wire colors.

View attachment 3449637

After thinking about it some more, I suspect the white/black wire on the relay connector is not connected to ground, the wire, it's splice in the harness or the terminal in the housing has failed somewhere. This would have an affect on all speed except low. You can test for this by unplugging the speed control relay and applying ground from the frame to any of the the three speed control wires (Black/White, LightBlue/Black, Black/LightBlue) and the fan speed should change. To fix you'd need to get that White/Black wire connected to ground or replace it's terminal if bad.

 

[therestevethedog]

Awesome, thanks so much for giving me that information. It’s pretty easy to get to that relay so this weekend it’s coming out and I’ll test that. Fingers crossed it’s that simple.

 

[therestevethedog]

Sure enough, that’s the problem. How hard is it to trace that line back? There’s not much room to work to cut & ground that wire. The blower box is in the way. Do I have to pull it and pull the bar that the glove box door is attached to in order to get it out?

 

[therestevethedog]

Got into it last weekend. Spliced the ground wire in the harness to ground and hallelujah I have all four fan speeds! Thanks again for the help