Block Heater Issue

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Dec 22, 2009 | 12:56 PM

boxcar1974

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From: Massachusetts

Block Heater Issue

One of the guys who works for me almost torched his truck twice today by plugging in the block heater. It sparks at the plug at the engine. We unplugged it from the engine and inspected for bare wires, loose terminal, and any damage to the cord. We found some damage to the wires as they pass through the bumper. Just enough to cause problems is touching the wrang spot. We wrapped them with electrical tape until he can buy a replacement. He plugged the cord back into the black heater receptical at the engine and plugged the heater into an extension cord it sparked even worse and actually caught fire at the engine plug. We unplugged it and discovered the electric grease was burning. We cleaned it and plugged it back in and no spark.

Does the heater have a short? Anything else?

Dec 22, 2009 | 01:17 PM

BPofMD

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From: Millersville, MD

Prob not....the grease caused the short to ground. Once you cleaned it, you said it didn't spark, right? And it did heat the block? Do replace the cord!

Dec 22, 2009 | 01:23 PM

Cowboy65

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From: Smiths Grove, KY

Disconnect the cord and check the heater resistance it should be around 15 ohms. Also check the heater to ground it should read as an open circuit. I suspect that it is a bad cord or loose connections at the heater terminals. Also if both the hot and neutral wires in the cord were damaged then it would cause a short circuit in the cord which would create all kinds of sparks. Did it trip the circuit breaker?

Dec 22, 2009 | 01:33 PM

gearloose1

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Something else.

Road salt.

IF the grease somehow absorbed salt and water, it can cause a short circuit.

Clean it all off.. I don't think outside connections exposed to salt spray should be greased.

A lacquer coating applied in the summer to reduce rust... sure, but grease????

Dec 22, 2009 | 03:30 PM

boxcar1974

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From: Massachusetts

I will check the ohms and circut reading for him tomorrow. It did not trip and breakers.

Thanks for the replies.

Dec 23, 2009 | 10:23 AM

boxcar1974

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From: Massachusetts

Checked it out this morning, it is reading 14.5 ohms and it has continuity. His heater did not work last night. Is the plug directional?

Dec 23, 2009 | 03:48 PM

firemanpat29

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From: Havana Fla

the element is simple just like a water heater. its ac so no its not directional. if you have 15ohms resistance, and its not shorted to ground all you need is a new wire, the wire may test (OHM) good but still have a break in it that wont pull the amps to make the heater work. Napa, oreileys, discount auto, international, or FOMOCO any of them should be able to get you the right cord.