Engine/Transmission (1998.5 - 2002) Block Heater Question

[InThinAir]

My 01 Truck is going on 150k miles. And something weird has started to happen in the last couple of cold nights. When the truck is wet. like melting snow, and I proceed to plug in the block heater it trips the breaker for that plug. When it is cold enough for it just to be frozen and dry it doesn't trip the breaker...



I took a look at the cord and it doesn't seem to have any cuts or rubs that I can see. I am wondering should just plan on replacing the cord or the whole heater and cord unit? Or is it something else?



Thanks for the Help...



---Doug

 

[steved]

My 01 Truck is going on 150k miles. And something weird has started to happen in the last couple of cold nights. When the truck is wet. like melting snow, and I proceed to plug in the block heater it trips the breaker for that plug. When it is cold enough for it just to be frozen and dry it doesn't trip the breaker...



I took a look at the cord and it doesn't seem to have any cuts or rubs that I can see. I am wondering should just plan on replacing the cord or the whole heater and cord unit? Or is it something else?



Thanks for the Help...



---Doug

Replace the cord... it has broken internally... had a 89 do this same thing... it was just the cord. The heater itself is pretty much solid state... it should either work or not work.



steved

 

[BK]

Is the breaker a GFI breaker?

 

[InThinAir]

I think the breaker in the box is GFI. I don't know what that would look like, but it does look different than the other breakers, and it has a test button. So if that is what one would look like, then yes it is GFI, I didn't know there was such a thing!



---Doug

 

[BK]

I think the breaker in the box is GFI. I don't know what that would look like, but it does look different than the other breakers, and it has a test button. So if that is what one would look like, then yes it is GFI, I didn't know there was such a thing!



---Doug

Yup sounds like a GFI breaker.

It detects leakage current to ground.

If it exceeds a few milliamps, pop - it breaks the circuit by throwing open the breaker.



The test button actually puts a little resistor to ground to simulate a ground fault, to see if the protection works.



That's why it doesn't do it when the water was frozen, only when wet.



I had the same problem, my outside outlets are protected by a GFI outlet, not a breaker. But I know the breakers are out there.



I had to go to a non-GFI protected outlet just for my truck heater.

My truck is outside, and if it rains and the timer turned on the truck heater, the wetness on the plug connection at the truck causes the leakage current and tripped the GFI, really annoying.



So you can either live dangerously like I do, or you gotta get something to protect the connection and keep the water off of it.

 

[steved]

Yup sounds like a GFI breaker.

It detects leakage current to ground.

If it exceeds a few milliamps, pop - it breaks the circuit by throwing open the breaker.



The test button actually puts a little resistor to ground to simulate a ground fault, to see if the protection works.



That's why it doesn't do it when the water was frozen, only when wet.



I had the same problem, my outside outlets are protected by a GFI outlet, not a breaker. But I know the breakers are out there.



I had to go to a non-GFI protected outlet just for my truck heater.

My truck is outside, and if it rains and the timer turned on the truck heater, the wetness on the plug connection at the truck causes the leakage current and tripped the GFI, really annoying.



So you can either live dangerously like I do, or you gotta get something to protect the connection and keep the water off of it.

Either that or the GFCI has gone bad... sometimes they will quit working properly under load.



I still think you will find you have another issue... I plug my truck into a GFCI breaker-equipped circuit and it has never caused it to trip... I do not protect the plug at all.



For what it is worth.



steved

 

[nps]

Sounds like the breaker is fine (doing what it is supposed to do) and your heater cord is bad.

 

[BK]

Wet = trips

Dry = doesn't trip.



Very typical of what the GFI will do.

Depends on how recessed the contacts are and such on your cord set (outlet on the extension cord and plug from truck cord going into it).

Mine didn't always trip, it was annoying chance of some times it did and some times it didn't when it rained.



Yup GFI outlets and breakers do go bad.

But IF it were a bad GFI breaker, it would trip from the load on a dry or iced up day.



With a wet Plug/outlet on the extension cord connection, GFI breaker is just doing it's job.



It's much easier for water to get between the blades of the plug and socket and the ground of the plug then it is to wick up into the trucks cord set to cause a Ground Fault.



If it were a bad cord set, up in the jacket some where it would trip the breaker either based on load current or GFI fault without moisture.



Of the plug or outlest on the extenstion cord have no cracks in their bodies, its just the leakage current from the wetness.



If you want to prove it... next time, dry off just the plug and socket, and reset the breaker, it'll be fine.

 

[Bob Cochran]

Yep dry off the plug and socket and to be sure spray both with WD-40 it will displace the moisture. Cannot tell you how many times I have used this in distirbutors to dry them out to start after getting soaked in water.

 

[BK]

Yep dry off the plug and socket and to be sure spray both with WD-40 it will displace the moisture. Cannot tell you how many times I have used this in distirbutors to dry them out to start after getting soaked in water.

#ad


Yup 100% agree with the WD40. . works great for this sorta problem.

 

[InThinAir]

Well, I hope to not have to plug it in anymore this year, so I will just leave the same cord on there and try to blow it dry with the compressor and use wd-40 next year and see what happens.



Thanks for all the help!!!



---Doug