Purchased a 2006 F350 CC with the 5.4l gas engine off of the lot in December. It came with the engine block heater.

I plugged it in, and it trips the GFI outlet that I have it plugged in to.

I tried a different cord, and had the same result.

The GFI outlet itself is okay, because I plug other things into it with no problem.

I looked in the Ford manual and see nothing that I can really do other than simply plug the heater in, so it doesn't appear that I am missing a step or something.

I looked in the manual at the fuses too; the engine block heater isn't shown listed anywhere, so it apparently doesn't have a dedicted fuse.

Anyone have any suggestions before I take it back to the dealer?

Thanks.

 

It might be the heater cord itself,I read in the forums it was cheaper to buy the kit rather than just the cord( Ithink).You might wanna check into that. It`s like running a coffee pot, and if you eliminated the outlet then the cords where I`d look

Hanklin

 

It could be that your block heater is exceeding the amperage limit for your GFI. IIRC the block heater draws about 15 amps. If you have a DMM you can check you heater for a short to ground if that is the case. However, I would suspect a weak GFI outlet first.

 

Thanks for the replies guys.

I think that the GFI is okay, as I've never had a problem with anything else I've ever plugged into it (power tools, etc).

The manual doesn't say anything special about where to plug it in, and the posts that I've searched on the block heater seem to be that people are able to just plug it into a regular outlet.

The cord that is on the truck now came with it. Bottom line is that I think the dealer will have to correct whatever is wrong with it.

 

Since this is your house wiring, don't assume anything. The consequences are too great. Get the outlet tested. Use a simple tester like this just to be on the safe side:

http://www.aemc.com/products/pdf/2121.02.pdf

The GFI device trips when it detects current flow on the ground lead. If the block heater isn't wired ciorrectly, you might have a situation where the neutral lead and ground lead reversed.

 

I agree with redford. If you can test the plug on the block heater, you should have heavy resistance between the two knife blades and nothing between either knife blade and the round ground blade. Anything showing to the round blade will trip the giffy.

Bad cord is my bet.

 

I'm betting the GFI can't take it. I have one outlet in my garage that trips when I try and plug in my truck. Other outlets work fine. I found that my satellite plugs into the same circuit, and the GFI can't handle it when I plug my truck in.

Check to see if you have anything else drawing current on that circuit.

 

I also pulg mine truck in on a 15amp circuit that is also GFCI protected, no probs. I was told that the 5.4 enigne block heater pulls about 750 watts, which is half of a 15amp load rating.

I am thinking it might be the block heater itself.

Have you tried pluging the truck into a different outlet?

 

I just went through this same problem. We've had a bit of snow and cold temps as of late. I did two things. First, clean the underside of the engine real well to ensure there is no residual build up of all the stuff they put down on the roads to remove snow/ice (mag chloride, salt, etc...). The focus here is the point where the chord connects to the engine. Then, I disconnnected my Marinco Plug (aftermarket device mounted to my bumper that my block heater chord is connected to). It was full of all kinds of stuff. I cleaned it up, reconnected my block heater chord, and then sealed it up with electrical tape (sides) and liquid electrical tape (top). No problems since.

Some input I got from another user at a different site:
"However, I would suspect that there is a film of Magnesium Chloride on the plug itself that is allowing a very small leakage between the prongs. It only takes a few miliamps to trip most GFI breakers. A local trucking company has a real problem with that up here. Try really cleaning with water and wiping the plug off with successive clean paper towels. You need to get the MagCl off as it absorbs moisture out of the air."

Mark

 

It all depends on what brand of outlet you have installed. Usually the outside circuit is wired in 14 wire and is rated for 15 amps. Some GFI's like Pass and Seymour and Cooper's don't hold very well. Levitons are in my opinion the best devices made.

Please keep in mind that if you have a 15A GFI, it will kick if overloaded, ground fault or not. I've seen claps of thunder trip them. Also keep in mind that a 15 amp GFI, or breaker for that matter, is only good for 12 amps of continuous draw.

 

What is the block heater rated at, amp draw or wattage?

 

I was told 1000 watts on my diesel - which I believe calculates out to just over 8 amps of current draw. I would think the gas engines are equal or less.

Mark

 

Also look into the connectins on your extension cord, wire size of the cord, and the length of the cord. But get the outlet checked first. GFI's are really fickle when it comes to any sort of heaters due to the fact that its measuring any lost current between the phase and the neutral. Most of the time heating elements will lose a couple of milli amps due to resistance that along with one coroded connection (check all your connections including on the truck) or an extension cord thats to long (less than 20') or to small (#12 stranded or bigger) or a weak GFI will trip it out everytime. You also have to remember most GFI's are protecting mulitple outlets so you also have to look into whats plugged into the circuit.

Good Luck

 

If it is a 15A GFI and the Block Heater pulls 8A then it shouldn't trip, But is there anything else on that circuit? You probably have something else running on that circuit and when you plug in the heater you are going over the max and it trips.

If you know there is something else on the circuit try unplugging it. Then try the block heater. I would suspect some big item like maybe a refrigerator, but it could be anything..

Just a thought...

 

Thanks for all of the replies and suggestions.

What I ended up doing was plugging it into a non-GFI outlet in the ceiling of my garage that has my garage door opener plugged in. I also put some dialectric grease on the truck side of the plug.

I didn't trip a fuse when I plugged the block heater into the garage ceilng plug, so I'll see in the morning if block heater has worked (if the engine is warm).

Regarding testing the outlets, I'm not an electrician and am not too comfortable messing around with electricity, plus I generally wouldn't know what I was doing. The only testing device that I have is something that plugs into a three prong outlet and has various lights on it to tell me if something is wrong. Everything showed "ok" when I plugged it into the GFI outlet that kept tripping.