1 speed blower fan (low) (1 Viewer)

[Girl und Panzer]

Hey yall,
I'm out of ideas here - I've replaced the relay in the driver footwell, the control box on top of the a/c Box, and the relay thingy on the bottom side of the a/c box. Still, I can't get but low speed on my fan. What else can I try? North American 94 fzj80

 

[White Stripe]

Check your voltage at the fan motor.

 

[sbman]

Low speed is driven by a 'blower resistor' component located behind the dash board.

FSM - 1994 FZJ80 EWD - https://forum.ih8mud.com/resources/1994-fzj80-ewd.96/

Page 23 of this manual, look for component B5, located in the right side dash behind the glove box. Not sure what it looks like but if that resistor has gone bad, your low speed will not work. You can check with a volt meter when you attempt to run the low speed blower, you'll see voltage on both sides if it is good, only on one side if it is bad. Or you can unplug it and check ohms, should see the following:

B 5 BLOWER RESISTOR
Pins 1–4 : 2.0 ohms
Pins 1–3 : 0.88 ohms
Pins 1–2 : 0.32 ohms

The 2.0 ohms is going to be your low speed, so if you see no continuity across pins 1-4, you've found your problem.

Page 162 of that same manual shows a drawing of the B5 connector, 4 pins, black in color to help locate the device.

 

[CJF]

Low speed is driven by a 'blower resistor' component located behind the dash board.

FSM - 1994 FZJ80 EWD - https://forum.ih8mud.com/resources/1994-fzj80-ewd.96/

Page 23 of this manual, look for component B5, located in the right side dash behind the glove box. Not sure what it looks like but if that resistor has gone bad, your low speed will not work. You can check with a volt meter when you attempt to run the low speed blower, you'll see voltage on both sides if it is good, only on one side if it is bad. Or you can unplug it and check ohms, should see the following:

B 5 BLOWER RESISTOR
Pins 1–4 : 2.0 ohms
Pins 1–3 : 0.88 ohms
Pins 1–2 : 0.32 ohms

The 2.0 ohms is going to be your low speed, so if you see no continuity across pins 1-4, you've found your problem.

Page 162 of that same manual shows a drawing of the B5 connector, 4 pins, black in color to help locate the device.

She *is* getting low speed. She isn't getting any *other* speeds.

 

[Girl und Panzer]

She *is* getting low speed. She isn't getting any *other* speeds.

Aye, low only I'm hoping it's not the fan motor, but I'll check the voltage. Guess I Might as well check that relay I bought too, they *said* it was good but I don't have data. If only I could just get new ones

 

[sbman]

Aye, low only I'm hoping it's not the fan motor, but I'll check the voltage. Guess I Might as well check that relay I bought too, they *said* it was good but I don't have data. If only I could just get new ones

Missed the 'but'. The EWD in that section is a mess, so many junctions and a 'shorting' connector, good grief!

It could be the motor I suppose. If low is really low probably not. If you can get to the blower motor plug and apply 12V directly to Pin 1 (Blue with a Yellow stripe), and GND to pin 2 (Blue with a red stripe) you should get HIGH manually, to verify that the motor can do it. It only has one set of windings.

Other suspect is the relay of course but also the HVAC control panel could be an issue or a bad connection somewhere along the way.

You can test the relay manually if you are good with an ohm meter and can hook up 12V to the 'high coil'. The relay actually has multiple relays built into it. To check the high circuit relay: Unplug the relay and check resistance on the it from pins 1 (+12, HIGH speed) (red-blue stripe), to (GND) on Pin7 (Blue with Red stripe). You should have some continuity there, about 10-100 ohms. If that checks out, jump 12V onto those pins and it should click, possibly audibly. While power is still applied, check continuity on pins 4 (Black/White stripe) to pin 3 ( White black stripe), it should be close to 0 ohms there, if it has no continuity while the power is applied to the coil, the relay is bad. take the power away and pins 4-3 should be open circuit.

To test the control panel with a meter, unplug it, find the 12 pin connector on it. Choose 'high' speed, and check continuity from GND Pin 16 (A12 B) (White/Black stripe) to Pin 13 (A12 B) (red/light blue stripe). With high selected you should have continuity, but open circuit when you select another speed.

 

[Girl und Panzer]

Low speed is driven by a 'blower resistor' component located behind the dash board.

FSM - 1994 FZJ80 EWD - https://forum.ih8mud.com/resources/1994-fzj80-ewd.96/

Page 23 of this manual, look for component B5, located in the right side dash behind the glove box. Not sure what it looks like but if that resistor has gone bad, your low speed will not work. You can check with a volt meter when you attempt to run the low speed blower, you'll see voltage on both sides if it is good, only on one side if it is bad. Or you can unplug it and check ohms, should see the following:

B 5 BLOWER RESISTOR
Pins 1–4 : 2.0 ohms
Pins 1–3 : 0.88 ohms
Pins 1–2 : 0.32 ohms

The 2.0 ohms is going to be your low speed, so if you see no continuity across pins 1-4, you've found your problem.

Page 162 of that same manual shows a drawing of the B5 connector, 4 pins, black in color to help locate the device.

I checked the pins on B5 and got .9 or.7 on all of them and .5 on 1-4 - does that mean anything? I'm guessing + on 1 or it doesn't matter - I'm no electric genius.
Edit - Fan runs high when jumped, so that's good. On the B6 control box, my ohm Meter reads 0.L (huh?) on 1-7 and didn't hear a click when jumping them maybe they sold me a bad box(es)?

 

[sbman]

I checked the pins on B5 and got .9 or.7 on all of them and .5 on 1-4 - does that mean anything? I'm guessing + on 1 or it doesn't matter - I'm no electric genius.
Edit - Fan runs high when jumped, so that's good. On the B6 control box, my ohm Meter reads 0.L (huh?) on 1-7 and didn't hear a click when jumping them maybe they sold me a bad box(es)?

The resistor is bypassed for high speed so I don't think that could be your issue, nothing on the B5 will help you much there.

O.L? Maybe that means no continuity? Is that the same reading you get when the meter isn't touching anything? Double checking the pin numbers on the EWD and it looks like I had them wrong. Check for 10-100 ohms from the relay pin 5 (Red/blue stripe) to pin 7 (Blue/Red stripe).

 

[Girl und Panzer]

The resistor is bypassed for high speed so I don't think that could be your issue, nothing on the B5 will help you much there.

O.L? Maybe that means no continuity? Is that the same reading you get when the meter isn't touching anything? Double checking the pin numbers on the EWD and it looks like I had them wrong. Check for 10-100 ohms from the relay pin 5 (Red/blue stripe) to pin 7 (Blue/Red stripe).

OK, I got 189 ohms between those 2, but hooking them to 12V did produce a click so the 6B box is good? Measuring 3 and 4 I got that 0.L (I think it means no continuity) but 2 and 3 got 0.0 or 0.1

 

[sbman]

OK, I got 189 ohms between those 2, but hooking them to 12V did produce a click so the 6B box is good?

Well, while you have it on 12V there, you should have continuity on pins 4-3. If you have continuity there while power is applied, the relay should be good for high speed. Even if it's clicking, the contacts could be corroded internally and not making connection.

 

[Girl und Panzer]

Well, while you have it on 12V there, you should have continuity on pins 4-3. If you have continuity there while power is applied, the relay should be good for high speed. Even if it's clicking, the contacts could be corroded internally and not making connection.

I went back and checked, I think I do since it read close to 0 ohms like you said. Most likely the switch is the issue then?

 

[Girl und Panzer]

Oh wait, it was 4 and 3 that had no continuity - so it is the box?

 

[sbman]

Oh wait, it was 4 and 3 that had no continuity - so it is the box?

While you have power on the coil (5-7) you should have continuity on 4-3 (0 ohms or close to it). If you have that, the relay is good at least on the 'high' setting.

While you have power on the coil (5-7) if you have an open circuit, no continuity on 4-3 , the relay is an issue on the high setting.

 

[Girl und Panzer]

While you have power on the coil (5-7) you should have continuity on 4-3 (0 ohms or close to it). If you have that, the relay is good at least on the 'high' setting.

While you have power on the coil (5-7) if you have an open circuit, no continuity on 4-3 , the relay is an issue on the high setting.

Sounds like that's the case then. Thanks for all your help!

 

[sbman]

As a final test, you can unplug the relay and then jumper it manually to see if you get high speed fan.

By doing this, you are doing the same thing the relay should be doing for you. Just be careful not to jumper the wrong ones, you could blow a fuse or damage the wiring harness.

To test:

Unplug relay

Test High speed: Jumper pin 4 (Black-White stripe) to pin 3 (White-Black stripe)

If you want to test medium-high speed, jumper pin 2 (Blue with black stripe) to pin 3 (White with black stripe)

If you want to test medium-low speed, jumper pin 1 (Black with blue stripe) to pin 3 (White with black stripe)

Of course you need to do this with the IGN in the correct position for any of it to work.

 

[Girl und Panzer]

As a final test, you can unplug the relay and then jumper it manually to see if you get high speed fan.

By doing this, you are doing the same thing the relay should be doing for you. Just be careful not to jumper the wrong ones, you could blow a fuse or damage the wiring harness.

To test:

Unplug relay

Test High speed: Jumper pin 4 (Black-White stripe) to pin 3 (White-Black stripe)

If you want to test medium-high speed, jumper pin 2 (Blue with black stripe) to pin 3 (White with black stripe)

If you want to test medium-low speed, jumper pin 1 (Black with blue stripe) to pin 3 (White with black stripe)

Of course you need to do this with the IGN in the correct position for any of it to work.

Thats a big help! My little wits end diagnostic jumper should finally get some use Gives me something to do while I hunt for a replacement, I don't see them in stock anywhere

 

[sbman]

Thats a big help! My little wits end diagnostic jumper should finally get some use Gives me something to do while I hunt for a replacement, I don't see them in stock anywhere

Hopefully you can confirm the issue that way. The Electrical Wiring Diagram in the resources section is a big help. Takes a bit of time to get used to reading it, but with a bit of studying, you can identify connectors and wire colors and their basic functions, even if you don't have deep electrical knowledge. Your relay is in the A/C section.

 

[Girl und Panzer]

Hopefully you can confirm the issue that way. The Electrical Wiring Diagram in the resources section is a big help. Takes a bit of time to get used to reading it, but with a bit of studying, you can identify connectors and wire colors and their basic functions, even if you don't have deep electrical knowledge. Your relay is in the A/C section.

As a final test, you can unplug the relay and then jumper it manually to see if you get high speed fan.

By doing this, you are doing the same thing the relay should be doing for you. Just be careful not to jumper the wrong ones, you could blow a fuse or damage the wiring harness.

To test:

Unplug relay

Test High speed: Jumper pin 4 (Black-White stripe) to pin 3 (White-Black stripe)

If you want to test medium-high speed, jumper pin 2 (Blue with black stripe) to pin 3 (White with black stripe)

If you want to test medium-low speed, jumper pin 1 (Black with blue stripe) to pin 3 (White with black stripe)

Of course you need to do this with the IGN in the correct position for any of it to work.

Yeah my brain cannot decipher the way that's written lol, thanks for the translation. So, no luck with any of these, but I did discover that my actual connector looks mighty screwed up - specifically the pin 3. Think that could be the problem? Maybe a fuse blew?

 

[Girl und Panzer]

Never mind! I had unplugged a harness for better access, turns out that matters to the fan speed

As a final edit, the speed control relay was just fine, plugging in the white connector was the trick. May this record serve to keep someone else in the future from being as embarrassed as I feel lol

 

[sbman]

Never mind! I had unplugged a harness for better access, turns out that matters to the fan speed

I'm confused. So did jumpering the connector make the fan run properly?

Either way, yes your connector damage there is certainly the issue, even if your relay is also bad. The melted pin, pin 3 is the ground path for all speeds M1, M2, and High. Low does not use that pin so it will work without it. So your symptom fits the damage there and it likely will not work correctly until you repair that connection. If you were able to jumper the fan to work into that melted position, that's only because you can get a connection manually, but you'll need the connector repaired to make good contact with the relay.

I believe that connector is part number 90980–10358, but I don't find it available anywhere. Repair pins/wires would be 82998-12060 and those do seem to be available, so if the pin is still removable without destroying the connector you might be able to salvage it that way, but it won't be a proper repair. You may have to get a used pigtail cut off a scrapped cruiser's harness unless you can find a replacement connector housing to use.