Outer Limits 4x4 Board

Hi there,
I've got a Hayman Reese electric brake controller installed on my 100 Series but the main 12V line running to it for power is connected via this little gadget mounted in the engine bay.







As you can see it's been shorted as the main casing of the unit is earthed but the 12V appeared to run through that plate which has "UFLEX B150" stamped on it. After some googling I found this appears to be some sort of thermoresistive metal.

Any ideas on what this thing is for and why my controller get's it's power via this much appreciated.

Most likely it was a thermal circuit breaker way back when.

Because it's there, I would just double check that your brake booster power supply has a fuse on it now.

Yes it looks like a self resetting thermal overload. Good ones are made by Cole and Hearse, but you can get cheaper Narva ones from Repco.
Hope this helps

A relation just bought an electric brake controller last weekend- they recommended a 20 Amp self resetting circuit breaker be installed. What you've taken a picture of is exactly that. I think he paid around $15 for a Narva one.

The metal bit would be a bi metallic strip that bends with heat (from excess current flow) to open the circuit.

I agree with the above - my father's Prado has something similar installed, which did exactly the same thing.

Buy the same thing again, and you can expect it to do the same thing.

Yes it is definitely a circuit breaker. Should have a 20 or 30 amp circuit breaker fitted, NOT a fuse.
The reason a circuit breaker is fitted is so it re-sets itself after the fault has discontinued so you have brakes again.

Should be under ten bucks from Burson's or Repco or similar.

Ruffy wrote:Yes it is definitely a circuit breaker. Should have a 20 or 30 amp circuit breaker fitted, NOT a fuse.
The reason a circuit breaker is fitted is so it re-sets itself after the fault has discontinued so you have brakes again.

Should be under ten bucks from Burson's or Repco or similar.

Sorry, I didn't mean to say a fuse specifically, I just meant that if the circuit breaker has been shorted across by the previous owner then you need to make sure there is some kind of replacement circuit protection in place.

Fantastic replies. Thanks everyone for the responses. After I posted this I realised that it obviously had to be some sort of circuit breaking device but I couldn't work out why it wouldn't be simple in-line fuse.
Thanks again.

floppinab wrote:Fantastic replies. Thanks everyone for the responses. After I posted this I realised that it obviously had to be some sort of circuit breaking device but I couldn't work out why it wouldn't be simple in-line fuse.
Thanks again.

Although I mentioned a fuse, I think Ruffy is right - a resettable circuit breaker is probably better than a fuse in this setting.