410 heater - 3 speed resistor??

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djc
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410 heater - 3 speed resistor??

Post by djc » Tue Dec 07, 2021 11:04 am

Any help with this please? The heater fan has ceased completely. Checked actual fan and it's running free, plus was working last winter.
I want to check the resistor that does the 3 speed settings - is it behind the dash somewhere?
Also I should take fan out to check properly - apart from a sod to get to, I can't release the connector into the fan, it seems to clip in somehow but can't see what I'm doing under there so trying to disconnect by feeling about.
Anyone know how to do this: access resistor; and disconnect fan supply?
'85 410, 1.3 5spd, SU44, SPUA, no mud.

Douglas

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Re: 410 heater - 3 speed resistor??

Post by donkeychomp » Tue Dec 07, 2021 9:04 pm

I've never had this problem but...a mirror on a stick will help you see what's what. eBay or any motor factors should have them.
If it ticks over...leave it

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djc
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Re: 410 heater - 3 speed resistor??

Post by djc » Wed Dec 08, 2021 8:39 am

thanks donkeychomp. Think I'll take driver seat out and get right down there, plus mirror trick.
Do you know where the 3 speed resistor is located - I'm guessing behind the 3 speed switch maybe... I seriously hope not the entire dash out!!!
'85 410, 1.3 5spd, SU44, SPUA, no mud.

Douglas

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Re: 410 heater - 3 speed resistor??

Post by donkeychomp » Wed Dec 08, 2021 9:02 pm

Not sure mate, I just hope it isn't a dash out job too...that is a right royal pain.
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Re: 410 heater - 3 speed resistor??

Post by kiwitony » Thu Dec 09, 2021 7:37 am

On our SJ410 the heater has been stunningly reliable, despite being under water a few times. I'll see if a photo can be arranged but surely the heater speed control is simply removed by removing the knob and then undoing the nut that holds the switch body to the dash? A SJ413 workshop manual has been uploaded to here which 'should' be similar to the SJ410 regarding the heater. https://drive.google.com/file/d/1NpCCX4 ... sp=sharing Section 7 is about the heater.

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Re: 410 heater - 3 speed resistor??

Post by djc » Fri Dec 10, 2021 7:55 am

Thanks kiwitony - managed to get a copy of that manual. Says the 3 speed resistor "is in the heater case". It seems to me there are only 2 wires into the actual fan so the resistor has to be before that - must be somewhere behind the 3 speed switch on dash... that's logical I think.
So 1] check fuse, 2] remove fan to check it is running with volts into it. 3] Get to resistor if necessary - can check volts to fan at each speed setting.
I did recently get inside heater box to clear the leaves out, I may have jammed some debris into fan so it's stalled.
Anyway, driver seat out so I can get into footwell better.
I suppose if yours has been under water that'll clean all the rubbish out?!
'85 410, 1.3 5spd, SU44, SPUA, no mud.

Douglas

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Re: 410 heater - 3 speed resistor??

Post by ROBBIE » Fri Dec 10, 2021 10:02 am

After reading this a couple of times I was sure the resistor is inside the heater and I’m now sure it is, but you need to be careful with it as it’s a coil that is just inside where the wires enter box. I’m positive this is it as on my old one the heater only worked at full speed and when I took apart to find out why and clean it the resistor had been crushed.
I could be wrong but I’m 99%
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Re: 410 heater - 3 speed resistor??

Post by kiwitony » Sat Dec 11, 2021 9:57 am

Yes, the heater resistor will be in the air flow inside the heater box. It needs to be there in the air flow as the resistor wires get very hot. The photos show all there is behind the switch is the connector to the fan unit. The plastic dash was removed about 20 years ago and trays made in the empty space to vastly increase storage area.

Attached is a wiring diagram detail of the heater switch and fan connections I think I got from this site for a 86-88 Samurai - the drawing was by Corey Daniels. Lg is light green - goes to a 15A fuse. You could try briefly putting 12v positive directly onto the positive fan terminal. The negative one is connected to the body. This would test if the fan motor itself is OK.
Attachments
20211211_192033 (Medium).jpg
20211211_191833 (Medium).jpg
Dices_Samurai_wiring_Diagram.jpg
Suzuki SJ Heater Connections.png
Suzuki SJ Heater Switch.png

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Re: 410 heater - 3 speed resistor??

Post by djc » Sun Dec 12, 2021 4:30 pm

Thanks again Kiwi - progress by accident here. Yes, resistor must be in heater box, all that's behind dash switch is the actual 4 setting switch.
Getting to the connector and the actual fan is a right sod. Decided to re-test switch- a few wiggles in case contacts dirty. Now I have low and mid speed without really doing anything. I'll live with that happily. The absolute ideal would be swap out the heater box with one that is really cleaned out, resistor, hoses etc checked. But that's a dash out surely and I do not fancy.
Anyway, appear to have some heat, so good for now.

thanks for all help.
'85 410, 1.3 5spd, SU44, SPUA, no mud.

Douglas

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Re: 410 heater - 3 speed resistor??

Post by ScottieJ » Sun Dec 12, 2021 10:47 pm

The resistor is usually mounted next to fan motor mount but it might be different on the early metal dash SJs like yours. I know on the plastic dash ones I can take it out without pulling the heater or fan. It’s on the driver side tucked up out of the way.
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