leeboy

Happy New Year everyone.....I went out to start my truck this morning and the wait to start lasted longer than normal....After work, i plugged it in and couldnt hear the sizzle.... I unplugged the cord from the block, plugged it in and im getting 120V at the female end of the plug...I screwed the cord back on the plug, and did a ohm/contunuity test. My multitester was set at 1.0 , i put the prongs on the male end of the cord, ( leaving out the ground) and the gauge stayed at 1.0 , if i touch the two prongs (on the multitester) ( red/black) togeather the gauge goes to "0" ....Does this mean the block heater is fried? If so, how much coolant do i need to buy ? Thanks gang!

Busboy

There must be continuity through the block heater. There will be some resistance but it must not be open which seems to be what you have.You can check for resistance to ground by touching one male terminal and the ground terminal with the meter while plugged into the block heater. There should be no continuity. Before replacing the block heater I would look very closely at the cord about 1/2 inch from the plug, if it's soft or dis-formed chances are it's broken internally from driving away with it plugged in. You could remove the cord short the two female ends together then check for continuity at the two male ends while wiggling the plug. I've seen this problem so many times it is almost always the cord.

leeboy

Wouldnt 120V at the plug show its working? Or if the wires are weak inside, it might not be enough to power the heater element?

Busboy

Usually what happens is the wire or wires break internally but the broken ends butt up against each other making contact intermittently. Also if using a digital multimeter this "samples" the signal and might not find an intermittent fault.

jrs_dodge_diesel

The sampling rate of most all multimeters these days will show intermitant continuity.

Yes it is possible for the block heater itself to go dead.

Put the leads of the meter on the two pins of the block heater itself. Should show about 17 ohms on the meter. Should show the same with the cord plugged in. You can also pull the cord again and check continuity while wiggling the ends to test for broken wires.

mulepackin

Good thread. Just had similar issues myself.

leeboy

Hey Mule what was your problem? So, by plugging the end into the extension cord and getting a 120v reading at the female end isnt a good enough test? Tomorrow after work i will test each of the 3 wires seperately, as well to see if i can wiggle the two prongs on the tester to the actually heater itself....

nickg

I'm confuzed by your 1st post...if it was sizzling ( or sounds like a kettle starting to boil) your block heater would be working,
to test heater and cord at the same time, set your multimeter leads one on each male end of the cord, your meter should show continuity, or the same as if you touched the 2 leads of the multimeter together, if it does not they test the cord and heater seperately,
another easy way to test if its working is to plug it in at night and unplug and you should hear/see the power arc as you unplug/plug it in.
lastly as mentioned above listen for the "kettle" boiling noise or feel around the block heater for heat

ronsram

i had probs. on my 01 with blockheater testing i unscrewed the locking collar that holds it on the block and pulled it to where i had both endss close together and tested it but also bent the male end(out by bumper) sevral directions and it would show then lose continuity ..my cord was bad..hope this helps

leeboy

Sorry Nick, i meant to put "Couldnt" hear the sizzle...Sounds simple to test....I did the unplug and plug last night to hear the power make contact....didnt hear nothing, so its either the cord or heater itself...Thanks gang

mulepackin

Basically the same problem as yours. I had my truck plugged in all night. Went to start at 6 deg. and it certainly didn't act like it had been plugged in at all. Long cycle time on the warmer, and turned over like it hadn't been plugged in. That day I checked for continuity and had it. Good power through the ext. cord, didn't even think to check the heater cord. That evening when I plugged it in it sizzled like usual. Gotta check the cord now.

Busboy

That could be, mines about 20 years old. I mostly use the old analog type because I can guarantee it will show an intermittent fault. I only pull out the digital when absolutely necessary.

leeboy

Ok....So the block heater element was shot. It was pretty coroded.....And the resistence test on the two prongs of the element failed....So, we put in a new one....Plugged it in and ....no hissing..or that clicking noise as it kicks in....I plugged a test light in the extension cord, and theres 120 power at the plug...Whats the chances of buying a defective block heater??

nitrousn

Did you use a new cord to the heater?

leeboy

Yes, it came with a brand new cord....I wonder if the brand dew jobber ones just dont sizzle like a stock one....Will see in the morning .....