Alternator suddenly red hot?
#82
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Here's the relays:
#85
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You my just not be using the meter properly. It sounds as if you are trying to read ohms across the contacts while the fan is on. That won't work. It is confusing the Multimeter.
The correct thing is to measure the amps, and then also measure the voltage drop across the contacts. Then you use Ohm's law to the resistance: Ohms = Voltage / Amperes
DNM
The correct thing is to measure the amps, and then also measure the voltage drop across the contacts. Then you use Ohm's law to the resistance: Ohms = Voltage / Amperes
DNM
#86
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You my just not be using the meter properly. It sounds as if you are trying to read ohms across the contacts while the fan is on. That won't work. It is confusing the Multimeter.
The correct thing is to measure the amps, and then also measure the voltage drop across the contacts. Then you use Ohm's law to the resistance: Ohms = Voltage / Amperes
DNM
The correct thing is to measure the amps, and then also measure the voltage drop across the contacts. Then you use Ohm's law to the resistance: Ohms = Voltage / Amperes
DNM
I just realized it was DNM and I put DKM earlier. My apologies. I certainly knew there was a K in it but it was in the middle of your last name.
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DMMs use a very small current source to create a voltage across the resisance being measured. If there is already a voltage there, it will muck the reading. I am glad to hear this is the reason for the reading you reported.
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You're right, I was touching 30 + 87 while the fan was engaged. I didn't realize that would make the difference to anything. For some reason I didn't think the meter was supposed to be bothered by things like that.
I just realized it was DNM and I put DKM earlier. My apologies. I certainly knew there was a K in it but it was in the middle of your last name.
I just realized it was DNM and I put DKM earlier. My apologies. I certainly knew there was a K in it but it was in the middle of your last name.
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This is how the new wiring was done without a fuse holder. Thankfully it runs much cooler than the store bought holder.
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Bench testing the relay in the closed position with no high current leads attached yields an ohm reading of 0.1 to 0.0 on the same meter.
I'll try doing the voltage drop and amperage measurement method you described in a bit.
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Relay is fine
Edit: now measure voltage from relay output to fan input.
3 measurements
Relay out to chassis
Fan in the chassis
Relay out to fan in (mV scale)
All with fan running and associated current measurements
Edit: now measure voltage from relay output to fan input.
3 measurements
Relay out to chassis
Fan in the chassis
Relay out to fan in (mV scale)
All with fan running and associated current measurements
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sixshooter
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