Thermal fuse help needed..

[Tube Screamer]

Hi guys,

I was wondering if anyone might be able to offer me some advice regarding a thermal fuse. I’m trying to repair a Nissan heater blower resistor, which unfortunately is now obsolete. I’ve managed to strip the unit down and remove the small internal printed circuit, and after testing a few components, I discovered that the thermal fuse is blown. I soldered a small jumper wire across the terminals to eliminate the fuse just for test purposes, and with the wire in place, the blower works perfectly.

So now I need to locate a suitable thermal fuse to replace the old component.. the problem is that I really don’t know what I need to buy. I’ve found many sites selling thermal fuses, but they all seem to offer so much more information than I have printed on the side of the tiny fuse, that I’m a bit unsure of what I need.

The fuse on the circuit board has a few numbers printed on it.. they are as follows:

2A ( but doesn’t state whether this is AC or DC)
140C
Then there is a number which is possibly a manufacturers part number N135 020
There are two initials TF (possibly IF)
And a couple of symbols.. there is a capital letter M within a rectangle, and also a capital letter T with a horizontal line above it within an inverted triangle.

Nothing else is printed on the fuse.. the component stockists who sell these things seem to also talk about voltage ratings (many are 250v), and amps related to AC or DC.. I have no idea how these relate to the fuse I’m trying to replace, as there’s are no other figures printed on the body of the component.

I was hoping that someone might be able to kindly advise me on what I need to buy, as I’m pretty confused with all of the available options.

Thank you in advance for any help or advice.. it would be very much appreciated

Russ

 

[shrtrnd]

It's a 140 degree C thermal fuse.
All the other information is manufacturer info. But you don't need to replace it with an original mfgr device.
Take it to an appliance repair supply store, electronics supply store, or possibly even an auto parts store and they should be able to fix you up.
A lot of guys here are from the UK, so you'll probably get input on suppliers (or even mail-order places if you need them), in your area.
My only other input is wondering if you might actually have a heat problem that caused that thermal fuse to fry.
Ive seen they go 'for no good reason' from time to time, but I'm wondering if it blew because you actually have a warm-air airflow problem with your Nissan, that might also need attention (to keep your replacement thermal fuse from opening).

 

[Tube Screamer]

Thank you for your reply.. so if I just buy a thermal fuse with the correct temperature, I don’t need to worry about the amps? This one states 2A on the body of the fuse.. but the component suppliers seem to say something like 2A (AC)/ 6A (DC).. I’m not sure whether the 2A on this fuse is related to AC or DC.. maybe it doesn’t matter?
And what about the voltage specification.. do I not need to worry about that either?

 

[Tube Screamer]

It is possible that there is another fault within the circuit somewhere, but the car is 15 years old, and so I’d imagine is this fuse, and I believe that these things weaken with age/use?
So I’m hoping that it simply blew due to these reasons, but if it did blow the new fuse, then obviously I’d need to investigate further..

 

[AnalogKid]

Assuming your device is powered by plugging it into the wall or some other connection to the mains, is there anything inside that would lead you to believe that the fuse is in a DC circuit rather than an AC circuit? Photos would help here.

2 A is the max current it can carry continuously, at any temperature below the thermal trip point, without blowing. For equivalent protection, you should replace it with an identically rated component.

M in a box - if the feet of the M are angled inward slightly, that is the logo for Matsushita, the parent company of Panasonic and Technics. Matsushita is a huge manufacturer of electrical and electronic components.

ak

 

[Tube Screamer]

Thank you for your reply.. this is actually a part from a car, and so doesn’t plug into the wall socket etc.. it’s the resistor which controls the heater blower. The car is obviously 12v, So would that mean I need a 12v fuse?

I’ve attached some

pictures detailing all text on the fuse..

Thank you

Russ

 

[Tube Screamer]

Hmm, that didn’t seem to work..

https://ibb.co/kQFUww
https://ibb.co/b54NGw

 

[Alec_t]

the car is 15 years old

Then the fuse is a DC one.

 

[(*steve*)]

You can get a fuse rated for a voltage higher than you expect to see, and for a thermal fuse, any current greater than you need it to pass.

The important thing in this case is the temperature.

Try to get as close as possible to 140C, and any current >= 2A, voltage >= 32V

 

[(*steve*)]

Try this.

Unfortunately you have to buy 10 at a time, but they cost peanuts.

You'll have enough for the next 150 years!

 

[Tube Screamer]

Thank you for your very helpful reply.. I notice that they also do one rated at 139C.. would you be more inclined to go for the 145C though?

 

[shrtrnd]

Look.
The thermal fuse is installed to protect some device in an electronic circuit. Probably a blower motor for your heating system. You don't want to install a 145C thermal fuse to protect the fuse. You want the thermal fuse to protect whatever device it's installed in there to protect.
I've got a 20 year old Nissan. Check your compartment filter to ensure it's not all clogged-up, since that might be what's causing things to overheat and take out the thermal fuse. I just wanted you aware of the fact that if you install another thermal fuse, (I'd go with the 139 degree one), and you lose it soon afterward. You'd need to identify a potential other problem somewhere.

 

[kellys_eye]

ESR Electronics, Cullercoats, UK, thermal fuses in a range of temperatures at 62p each.

https://www.esr.co.uk/electronics/products/frame_fuses.htm

 

[(*steve*)]

ESR Electronics, Cullercoats, UK, thermal fuses in a range of temperatures at 62p each.

https://www.esr.co.uk/electronics/products/frame_fuses.htm

Three times the price of the RS ones, but they are 10A.

Note the instructions to crimp them, not solder them.

Thank you for your very helpful reply.. I notice that they also do one rated at 139C.. would you be more inclined to go for the 145C though?

Yes, I probably would.

 

[dave9]

I've seen the transistors on those blower controllers fail on other vehicles, think I would just as soon spend the ~ $11USD (£7.46 delivered) it costs for that entire module. I don't know if this part is the exact model your vehicle uses but from the back of the circuit board it looks very close to what you pictured, and gives some idea of what these modules sell for.

https://www.ebay.co.uk/itm/Blower-M...Nissan-Primera-P12-Almera-Navara/122820240211

https://www.ebay.co.uk/itm/Blower-M...ra-P12-Almera-N16-Navara-D22-New/253008801788