I've spent about an hour reading up on engine block heaters on this site, but havent found anything on my problem. It seems my block heater works only when it wants to. I'll have it plugged in overnight, go to start it up, and its still cold. Last night I got home around 1 AM, plugged it in, didn't hear a kettle sound, but didn't think anything of it. This morning around 8:30 I go to start it and its freaking cold again and revs high has hell because its cold when I get going. I've read on here you can only have it plugged in for about 4 hours, then others say 8, but I never seen a true answer, some of you guys have timers, but I see it as it'll pull more amps getting it warm then right after truck was turned off and leaving it plugged in over night. I have no idea if these things get worn out and work occasionally or what. Any help appreciated.

Thanks

 

i plugged mine in around 3 yesterday afternoon on my diesel...
first time this season..
this am around 8 it was 15 here..
turn key and no problems

i leave it plugged in all weekend even if i'm not going anywhere
never had any problems

follow the cord to the heater and make sure there are no chaffes in the wiring
and make sure to use dielectric grease on the plug to keep moisture out and to keep the connection clean

...zap!

 

Thanks for the quick reply. The cord is stretched out from my garage to end of driveway, so it's pretty straight. The prongs are clean, I took some sandpaper to them, but indeed I will go pick up some conducitve grease. thanks

 

Leaving it plugged in doesn't hurt it but in isn't efficient. It only takes about 3-4 hour to get it up to temp and this is why people only set it to come on 4 hours before they plan on driving.
Like zap said, check the cord especially where the cord actually plugs into the heater element. it may be loose or corroded there.
Also how long is the extension cord from the house to the truck?

 

Yeah it really sounds like the heater isnt even working, check under the hood after heating see if block is indeed warming up. Ive never used one a these heaters so I really am not exactly sure.

 

Hard to say, its a pretty long cord. probably 25-40 feet. I don't think its not working at all because sometimes when it feels swell enough it works. I know its pulling amps sometimes because when I go to plug it in the cord is stiff as hell, and when I go to unplug it, its flexible because of the current flow.

 

the length of the cord may be the reason its not working. if it draws too much the the cord gets hot and it will increase the resistance even more. try a shorter and a heaver duty cord. the shorter the better. you don't want the cord catching on fire in the middle of the night.

 

i only need 4 to 5 feet of cord to reach the truck from the shed...however
i use a extention you'd use for a a/c unit
flat and rather big

yeah i know its not "efficent" to leave it plugged in all night or whatever but i'm just a lazy *** that could always just throw the breaker in the cellar by day and re-set it by night


but i'm lazy

...zap!

 

Even it being such a long cord, I don't understand why it works one day, yet not the other. It has constant source of electricity, not like it kicks out the breaker or anything. I'll try and find a shorter cord though

 

I was just told that these engine block heaters have thermostats. Is this true??? Maybe that would be the answer

 

It's all easy to test with a meter set on a low resistance scale.

 

I've never heard of a block heater with a thermostat. A block heater is nothing more than an electric element, similar to that of a water heater or stove top kettle, that uses about 1000w give or take a couple hundred (which is why you don't want to leave it on all night, it's like having ten light bulbs on). You can get away with a longer extension cord if it is in good shape and properly rated for outside use. The reason a long cord could be a problem is because the block heater will receive less voltage as the length of cord increases, but I think it would be negligible on anything less than 100'. It sounds to me like you have a poor connection somewhere, just try a cord you know is reliable, and if that doesn't work, then yes, you may have to replace the heater. You can also get re-circulating in-line heaters that splice into your heater hose and pump your antifreeze through the system. They are more efficient than a block heater, but also more expensive.

 

You need to use a test meter to check the circuit. flex the plug end of the wire as you test to check for a bad internal wire. My block heater never warmed the engine enought to show on the temp gauge. If you just need to have extra warmth for the first few miles, then a heated seat is wonderful!! The kit is only $100 and takes hour or two to onstall.

 

Many heating units have a removable cord that plugs into the heating unit, if your's does I would check that plug for corosion and a tight fit. an ohm meter will tell if the element is good or open also when checking use the ohm meter between each wire and the block ground many times when the element fails it will fall and touch the block inside, it is a very close fit in there. The only heaters that I have ever seen with a thermastat are the old style that went in the heater hose these were good but took huge amounts of power to operate.

 

Thanks guys. I'ma go try some of these things