Boy, did we get lucky!! I was removing the old insulation in the engine compartment and tried to pull the plug out of the wall outlet so I could get remove the outlet in prep for the new insulation. The male end of the plug was melted right into the outlet. If you looked at the end of the plug the bar on the left was gone!! melted completely or corroded away. Some green stuff. The female outlet had the matching orifice melted/gone also, along with the plastic melted all out of shape.
Guess this connection should be checked periodically. I never did because when I actuated the switch at the foot of the bed the red light came on. Apparently when I replaced the circuit breaker three years ago the plug was bad then. Here all this time I wasn't turning on the block heater but only turning on the red indicator light.
Lucky we didn't have a fire!! Hopefully others will check their block heater plugs for corrosion/poor contacts.
Mine wasn't that bad, but I suspect that the block heater that was on the coach when we bought it last year hadn't worked for some time. The cord was quite brittle. Again, very glad we didn't have a fire. I do look the cord over each time I look in the engine area.
A very fortunate situation indeed! Looks like you averted potential disaster. I had a similar situation only with the refrigerator plug outlet. It kept switching over to gas when I was on electric and I couldn't figure out why till I looked at the outlet where the plug is and found it burned up. The plug was very corroded and the heat built up from there. Exposed more to the outside elements and the engine compartment these plugs need to be checked periodically for corrosion. The next time I check the refrigerator plug I will check the block heater plug also.
Thanks,
Jerry aka Murph
I had a similar issue. The red light on switch worked though the cord was chewed through (looked like mice had). I had thought was working until had problems starting when cold (as block heater was not receiving electricity) tho light seemed to say was on. Changed out electric cord and voila , block heater working great. Good advice to check.
I carry one of those non-contact digital temp meters in the coach. Very handy for checking brakes, tires, A/C output, etc. Whenever I use the block heater, I verify operation with the meter. When you turn the switch on, you should see an immediate rise in temp where the block heater screws into the engine block. If not, you've got a problem.
Good idea to periodically check the outlet plug where the block heater plugs in. Before leaving for a trip, turn the block heater on and five minutes later, put your hand on the block where the heater goes in. Should be warm.
Block heaters may be 1000 or 1500 watts so high resistance from corrosion, etc. will cause excessive heat and damage (or worse) at the outlet/plug.
Took me 15 minutes to get our 6V-92TA started without the block heater in Yellowstone at 19 degrees and 8000 feet. High resistance had melted the wire where it makes contact at the block heater. No mosquitos survived in the area after it started.
Pierce
Actually, the "eye-ball" inspection one usually gets from doing your own minor servicing (chassis lube, for example) is invaluable for spotting potential issues.
When doing mechanical inspections, I spend as much time UNDER the coach as inside it, since there is where the "machinery" lives.
Mine was chewed thru too. I just use the Aquahot now.
John, I do not have Aquahot. When my coach was new there was a little tag in the engine compartment that read: Keep bonfire under motor small during extreme cold weather!! ;D ;D
I also upgraded to a stronger starter and put in a new ground wire and ran a direct wire to the starter. I never need the boost switch even in cold weather and not running the AH.
RE: When I turn the block heater on, I verify operation
After buying a non-contact IR thermometer, another tool to own is Kill-O-Watt
P3 P4400 P3 P4400 Kill A Watt Electricity Usage Monitor - Low Temperature Alarms (http://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU)
Using Kill-O-Watt to check your engine block heater is maybe a better way to know if the heater is working.
It is also a good tool to measure how much electricity a plugged-in appliance uses over hours or days. We used it to check our new electric refrigerator.