New here. I have a DK45SE that when the key switch is turned to the first position (where the glow plugs kick in) it blows the 60A main fuse. I just installed a new starter and a new key switch. It was doing this before the new components were installed. I disconnected the glow plugs and tested the circuit. Timer comes on, the glow plug light comes on for 15 seconds and 12v present at the plug. The fuse does not blow when the plugs are disconnected. I pulled all of the glow plugs and tested them. All at 0.8 ohms and tested on a battery for proper operation. For the moment I am running without the glow plugs connected and everything works fine. Any suggestions? Thanks in advance. There seems to be a lot of knowledgeable people here and a great community.
Fuddyduddy1952
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Glow plug resistance should be 1 to 6 ohms from what I looked up.
WinterDeere
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How many plugs are on this circuit? 0.8 ohms would draw 15 amps at 12 volts, if the resistance doesn't change much with temperature.
I'm no glow plug expert, but I suspect they're PTC = positive temperature coefficient. So your 0.8 ohms cold may indeed translate to Fuddy's 1+ ohm values when warm, and even less than 15A each once heated.
I suspect you may have a glow plug that's expanding and shorting when it gets hot. Check the data on your fuse part number, and you'll probably find you need several times 60A to cause the fuse to blow in any short time.
I'm no glow plug expert, but I suspect they're PTC = positive temperature coefficient. So your 0.8 ohms cold may indeed translate to Fuddy's 1+ ohm values when warm, and even less than 15A each once heated.
I suspect you may have a glow plug that's expanding and shorting when it gets hot. Check the data on your fuse part number, and you'll probably find you need several times 60A to cause the fuse to blow in any short time.
I have 2 good plugs that I picked up for spares and they measure the same. No time to heat up before it blows. I got some replacement fuses from Amazon. They were sold as slow blow but I don't think so. Guess zi just need to get a proper 60aA fuse but it still shouldn't pull 60A.
WinterDeere
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I think you're missing the point. A 60A fuse will typically take something like 300A to blow in 1 second, or 1200A to blow in 0.1 second. If you want more accurate numbers, consult the time/temperature curve for your fuse part number.
But ignoring the tedium of exact numbers, if you say they're blowing nearly instantly, you have a short circuit. If you're positive it's not in one of the glow plugs, then it's in your wiring. Period.
If disconnecting all the glow plugs prevents the fuse from blowing, then you know it's either a plug or the wiring in that branch of the circuit. I would disconnect all glow plugs, then reconnect them one at a time, until you find branch of the circuit blowing the fuse. Then you can swap out that plug to find out if it's the plug itself.
But ignoring the tedium of exact numbers, if you say they're blowing nearly instantly, you have a short circuit. If you're positive it's not in one of the glow plugs, then it's in your wiring. Period.
If disconnecting all the glow plugs prevents the fuse from blowing, then you know it's either a plug or the wiring in that branch of the circuit. I would disconnect all glow plugs, then reconnect them one at a time, until you find branch of the circuit blowing the fuse. Then you can swap out that plug to find out if it's the plug itself.
Fuddyduddy1952
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The glow plugs were in parallel. Four 0.8 ohm=0.2 ohms at 12.6V=63 amps.
Good troubleshooting advice from winter, simply connect one at a time.
An induction ammeter like this is handy because you don't have to disconnect anything. Back of meter has a slot you just put over battery cable or wire going to 60A fuse.
Current draw should be same for each glow plug.
Good troubleshooting advice from winter, simply connect one at a time.
An induction ammeter like this is handy because you don't have to disconnect anything. Back of meter has a slot you just put over battery cable or wire going to 60A fuse.
Current draw should be same for each glow plug.
WinterDeere
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Everyone complains about "made in China", until they need a cheap meter to get the job done:
Unlike the antique Amprobe clamp-on meters, these measure AC and DC currents. But being digital, they may not have time to even respond to a short pulling battery-level currents. Sometimes analog needles are nicer.
Unlike the antique Amprobe clamp-on meters, these measure AC and DC currents. But being digital, they may not have time to even respond to a short pulling battery-level currents. Sometimes analog needles are nicer.
Starter ground may be bad, so it's back flowing thru the glow plug circuit. Without the plugs wired in, it's finding another pathway. The 60+ amps is the starter load backfeed.
If so, disconnect the heavy wire from the starter, and see if the glow plugs work as they should. The starter won't roll, solenoid MIGHT try to pull in (also could be bad ground related). Another way to check would be to hook a grounding starter cable from the battery neg to the starter housing.
Just a wild guess. Couple of Fords with the woven grounding strap drove me nuts for a while.
If so, disconnect the heavy wire from the starter, and see if the glow plugs work as they should. The starter won't roll, solenoid MIGHT try to pull in (also could be bad ground related). Another way to check would be to hook a grounding starter cable from the battery neg to the starter housing.
Just a wild guess. Couple of Fords with the woven grounding strap drove me nuts for a while.
Fuddyduddy1952
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Do you have this meter? Curious because one review says: "The amp meter part has never worked and didn’t even know it until I needed it for the first time. Everything else is great but I got it for the amp clamp".
Maybe he got a defective one.
I use both analog and digital. I have this ammeter and it works, I'd rather see the analog movement than flashing numbers for this application.
That fused 60 amp circuit goes many places and my curiosity is what the current draw is with glow plugs disconnected. It's possible having a load then adding plugs blows fuse.