Happened this week. Worked one night, then the next didn't. Checked the timer and the 20 ft extension cord with a light, both working. Removed the extension cord from the timer and plugged directly into a wall socket all night, and nothing. Checked the electrical cord to the heating unit (the best I could since it's not easy to see) and didn't see anything unusual. Installed myself a little over a year ago in my 2009 TCH. Anyone else had this happen?

Next step will be to buy another and install .. :-(

 

Bad time with the cold weather to have this happen. I measured across the plug and it was around 40 ohms best I can remember. Just a possibility the cord plug (block end) directly to the block heater may have somehow slipped loose or partially loose. I doubt your driving in the deep snow would get up that high due to the wind deflector panels under the engine.

Mine also went cold not long ago. I had added a short heavy duty extension only 6 feet long. It had a flaky plug I had added myself was open. I cut and reattached it and it works fine now.

Good luck on your finding the problem.

 

I have a Ford Escape Hybrid and the block heater is a couple years old and working fine.

I've had block heaters in cars since I spent two years in Idaho in the 70s. I've found that they typically last 3-4 years. Sometimes the failure isn't the heater itself but the cord to it. I replaced a block heater on my Suburban a year ago only to find the cord bad. Now I have a spare heater element.

The block heater should have a resistance reading of about 36 ohms if it's a 400 watt element. (ie Voltage squared divided by the wattage = the ohm value)

So check out the cord to the heater (look closely at the plug end that goes into the heater element) and make sure that isn't the problem before opening up the coolant system.

 

Bill - Jimmy. Thanks for the advice. Haven't had time to get get down where the cord meets the element to see if it came unplugged, but I'll check the ohms and if I don't get anything -- that will be a good indication it came unplugged or went bad. Perhaps I can get to it sometime this week or next. Let you know what I found out ...

 

Also, curiously, the block heater plug on the power end has just gone intermittent on my FEH. Will have to cut it off and put on another plug. I suppose it just worked the wires 'til one broke.

 

Did you ever forget and try to backup/drive off with the cord connected? I can see that may make it go intermittent/defective a little faster. I have never done that as I hang the cord over my driver’s side mirror so very obvious and reminds me to disconnect. How did you determine it was the cord end versus at the element or a bad element?

 

Did that on my Suburban but not the FEH. Must have just worked loose. Some extension cords are harder to remove the plug from than others.

Used a volt meter, disconnected the plug at the heater end of the cord, put in the volt meter probes and wiggled the wire just behind the standard plug at that end. Volt meter needle wiggled etc.

 

Duh! Problem solved but perhaps a new problem! When I was going to check the ohms, I noticed the wire behind the end of the heater cord was melted and broken. I took some pictures, but don’t know how to post. This could lead to another problem, why was in melted/burnt? This also perhaps solves the mystery that a couple of nights ago, my electrical breaker on my garage circuit had popped. I reset, but didn’t have a clue what would have overloaded it to pop. Now perhaps the mystery is solved. I can get another male end for the cord, but not sure I should do that if something else is wrong such as something malfunctioning in the heater element? Any ideas?

 

First take an ohmeter and check out the heater element. Measure it pin to pin and look for the ohms appropriate to the wattage rating. Then measure it pin to ground, both pins. These should be high resistance if one is low that's the source of your problem and you need a new heater unit.

These is most likely a third pin that is the ground, it should be grounded (of course!).

Also look at the routing of the power cable. It may have partially melted if it was close to an exhaust component. Then it grounded and voila a short.

My wiring cable from Ford has a lot of cable to allow it to arc out & away from exhaust components and is covered with a silvery heat shield.

 

Thanks for the tip on checking the ohms. The cord isn't anywhere near the exhaust and actually comes out the front of the car under the bottom grill. Not close to anything hot; however, perhaps when I'm pullling it lose from the power cord I could have some how damaged it over time causing some kind of an arc that cause the melting (that would be along shot!). We'll soon now when I check out the ohms.