Usually, when I've had a cord fail, it has been at the block where the cord plugs in, you may need to do your resistance test there. My old 6.2 diesel block heater draws 8 amps, with 120VAC that's around 1000 watts-in the neighborhood of 15-16 ohms. If you put your meter on the wall plug end of the cord & get infinity, try wiggling it where it plugs into the actual block heater-bet your meter starts jumping around!
How do you test a block heater with a multimeter?
- Thread starter Carnoobie
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Originally Posted By: RiceCake
Or take that plug end off and test the bare wires with a multimeter.
Your block heater cord might be bad somewhere else or the block heater is bad.
Edit: Or you wired it wrong.
Im 99% certain i didnt wire the plug wrong. I did as everyone here said, i have 2 black wires on mine plus the 1 green.
If I end up buying a new plug tommorow, since ill have the wires out ill try doing the test then too.
Originally Posted By: bullwinkle
Usually, when I've had a cord fail, it has been at the block where the cord plugs in, you may need to do your resistance test there. My old 6.2 diesel block heater draws 8 amps, with 120VAC that's around 1000 watts-in the neighborhood of 15-16 ohms. If you put your meter on the wall plug end of the cord & get infinity, try wiggling it where it plugs into the actual block heater-bet your meter starts jumping around!
The sad thing is, ive tried so many times seeing where the plug leads to but i cant even locate where the [censored] block heater is! Very frustrating, i know its on the passenger side of the engine bay but ive tried looking and ah just too many wires around there.
Or take that plug end off and test the bare wires with a multimeter.
Your block heater cord might be bad somewhere else or the block heater is bad.
Edit: Or you wired it wrong.
Im 99% certain i didnt wire the plug wrong. I did as everyone here said, i have 2 black wires on mine plus the 1 green.
If I end up buying a new plug tommorow, since ill have the wires out ill try doing the test then too.
Originally Posted By: bullwinkle
Usually, when I've had a cord fail, it has been at the block where the cord plugs in, you may need to do your resistance test there. My old 6.2 diesel block heater draws 8 amps, with 120VAC that's around 1000 watts-in the neighborhood of 15-16 ohms. If you put your meter on the wall plug end of the cord & get infinity, try wiggling it where it plugs into the actual block heater-bet your meter starts jumping around!
The sad thing is, ive tried so many times seeing where the plug leads to but i cant even locate where the [censored] block heater is! Very frustrating, i know its on the passenger side of the engine bay but ive tried looking and ah just too many wires around there.
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Just started the car this morning and still same thing. So I got a new plug from home depot and going to try hooking up the MM prongs to the bare wires of the block heater cord. If theres nothing then [censored]!!!
Would this be a dead cord?
Should i just go buy the Plug Alive tool for $20?
Would this be a dead cord?
Should i just go buy the Plug Alive tool for $20?
Considering you don't know if the block heater is working yet, and now you see the poor quality of aftermarket plugs, I stand by my original suggestion of getting a Temro or equivalent cord and replacing the entire cord length. Yes, it's going to be a nuisance tracing the cord back, and it's going to be an nuisance to string it in.
However, then you'll know exactly where your block heater is and can actually test that. Then, you'll also have a proper, working cord that is a little more resistant to the cold and moisture. Do note that these new ends tend to be designed for dry conditions and moderate temperatures. I've never had one work exactly right when spliced onto a block heater cord, which is why I refuse to use them now. I simply replace the entire cord.
However, then you'll know exactly where your block heater is and can actually test that. Then, you'll also have a proper, working cord that is a little more resistant to the cold and moisture. Do note that these new ends tend to be designed for dry conditions and moderate temperatures. I've never had one work exactly right when spliced onto a block heater cord, which is why I refuse to use them now. I simply replace the entire cord.
Garak, i cant even locate the [censored] POS block heater, its really [censored] me off. From what i see, the cord runs to under the airbox and looks like ill have to remove the airbox just to find out. Stupid.
I need to find out what end the cord uses first before replacing it. I dont wnat to replace the cord unless i know forsure its that.
I need to find out what end the cord uses first before replacing it. I dont wnat to replace the cord unless i know forsure its that.
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Originally Posted By: Carnoobie
I need to find out what end the cord uses first before replacing it. I dont wnat to replace the cord unless i know forsure its that.
The problem is always finding a replacement plug that works anywhere near as well as the original. I've dealt with many cars that have had replacement plugs, and I hate them without exception.
I need to find out what end the cord uses first before replacing it. I dont wnat to replace the cord unless i know forsure its that.
The problem is always finding a replacement plug that works anywhere near as well as the original. I've dealt with many cars that have had replacement plugs, and I hate them without exception.
Did you ever put your ohm meter on the bare (black) cord leads after taking off the cheapo plug? If still showing open circuit (no reading change when you touch the meter leads to the two black wires), then you have 3 possibilities:
1) the cord itself is broken or cut somewhere between your splice job and the actual heater.
2) the connection of this cord at the block heater is corroded and has lost connection (continuity) due to this corrosion.
3) the block heater itself has burned out and now has an open circuit internally and will need replaced.
My guess is that scenario #2 is the most likely, but you will have to dig further to get your answer. You sound like the kind of person that gets easily frustrated when messing around under the hood of your car....might be good to find someone to help you there? Some people actually enjoy that kind of stuff....I would help if I was closer.
1) the cord itself is broken or cut somewhere between your splice job and the actual heater.
2) the connection of this cord at the block heater is corroded and has lost connection (continuity) due to this corrosion.
3) the block heater itself has burned out and now has an open circuit internally and will need replaced.
My guess is that scenario #2 is the most likely, but you will have to dig further to get your answer. You sound like the kind of person that gets easily frustrated when messing around under the hood of your car....might be good to find someone to help you there? Some people actually enjoy that kind of stuff....I would help if I was closer.
Originally Posted By: bmwtechguy
Did you ever put your ohm meter on the bare (black) cord leads after taking off the cheapo plug? If still showing open circuit (no reading change when you touch the meter leads to the two black wires), then you have 3 possibilities:
1) the cord itself is broken or cut somewhere between your splice job and the actual heater.
2) the connection of this cord at the block heater is corroded and has lost connection (continuity) due to this corrosion.
3) the block heater itself has burned out and now has an open circuit internally and will need replaced.
My guess is that scenario #2 is the most likely, but you will have to dig further to get your answer. You sound like the kind of person that gets easily frustrated when messing around under the hood of your car....might be good to find someone to help you there? Some people actually enjoy that kind of stuff....I would help if I was closer.
No because its under the car and i cant jack up the car cause of all the snow here so mech is gonna do it for me tomrw and test it.
I have a good feeling its the cord which is cheap fix.
Did you ever put your ohm meter on the bare (black) cord leads after taking off the cheapo plug? If still showing open circuit (no reading change when you touch the meter leads to the two black wires), then you have 3 possibilities:
1) the cord itself is broken or cut somewhere between your splice job and the actual heater.
2) the connection of this cord at the block heater is corroded and has lost connection (continuity) due to this corrosion.
3) the block heater itself has burned out and now has an open circuit internally and will need replaced.
My guess is that scenario #2 is the most likely, but you will have to dig further to get your answer. You sound like the kind of person that gets easily frustrated when messing around under the hood of your car....might be good to find someone to help you there? Some people actually enjoy that kind of stuff....I would help if I was closer.
No because its under the car and i cant jack up the car cause of all the snow here so mech is gonna do it for me tomrw and test it.
I have a good feeling its the cord which is cheap fix.
Originally Posted By: RiceCake
The OP's question was if he should test it with the car hot or cold, I never had a doubt that some materials exhibit resistance shift.
And even then there would be only very minute effects on the resistance, probably not even measurable given the inherent inaccuracies of the multimeter, the added resistance of the extension cord, possible corrosion, manufacturing tolerances...
Dunno, as I've never seen one in Australia, but if I were making block heaters, I'd use an RTD, as it would drop the current as temperature comes up.
Have, however, seen people use RTD type engine temperature senders to heat a diesel injector pump when they want to run vegetable oil...self limiting resistance heating.
The OP's question was if he should test it with the car hot or cold, I never had a doubt that some materials exhibit resistance shift.
And even then there would be only very minute effects on the resistance, probably not even measurable given the inherent inaccuracies of the multimeter, the added resistance of the extension cord, possible corrosion, manufacturing tolerances...
Dunno, as I've never seen one in Australia, but if I were making block heaters, I'd use an RTD, as it would drop the current as temperature comes up.
Have, however, seen people use RTD type engine temperature senders to heat a diesel injector pump when they want to run vegetable oil...self limiting resistance heating.
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