Engine barely turns over, need help |
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Engine barely turns over, need help |
solex |
Jun 20 2020, 10:41 AM
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#1
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Senior Member Group: Members Posts: 789 Joined: 12-January 05 From: Long Island, NY Member No.: 3,439 Region Association: North East States |
I have done a lot of work and had the car running fine for serveral but now I have an electrical problem that I cannot seem to find.
Symptoms: Starter will turn a few degrees but will not turn over the engine when I release the key the starter will turn over a few more degrees as though I still have the key in the start position. What I checked:
Recent work done (may not be relevant):
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Superhawk996 |
Jun 20 2020, 02:00 PM
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#2
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914 Guru Group: Members Posts: 5,875 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
0.1 ohm is too high of resistance
Ohms Law voltage = current x resistance Stating can draw several hundred amps Let’s use 100 amps to keep the math easy 100a x 0.1 ohm = 10 volt drop You can see how even a 50a starter current will drop 5 volts across that strap. Not good. |
solex |
Jun 20 2020, 02:21 PM
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#3
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Senior Member Group: Members Posts: 789 Joined: 12-January 05 From: Long Island, NY Member No.: 3,439 Region Association: North East States |
0.1 ohm is too high of resistance Ohms Law voltage = current x resistance Stating can draw several hundred amps Let’s use 100 amps to keep the math easy 100a x 0.1 ohm = 10 volt drop You can see how even a 50a starter current will drop 5 volts across that strap. Not good. I just checked the specs on my meter and 0.1 is the lower limit of the meter so I would need to get a better meter to confirm the actual resistance of the strap but will order a new one |
Bartlett 914 |
Jun 21 2020, 10:55 AM
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#4
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Advanced Member Group: Members Posts: 2,216 Joined: 30-August 05 From: South Elgin IL Member No.: 4,707 Region Association: Upper MidWest |
0.1 ohm is too high of resistance Ohms Law voltage = current x resistance Stating can draw several hundred amps Let’s use 100 amps to keep the math easy 100a x 0.1 ohm = 10 volt drop You can see how even a 50a starter current will drop 5 volts across that strap. Not good. I just checked the specs on my meter and 0.1 is the lower limit of the meter so I would need to get a better meter to confirm the actual resistance of the strap but will order a new one I would agree with that. Measuring very low resistance has too many variables and is often unreliable. I am sure the cable is fine but the problem was properly cleaned and seated connections. Glad you are up and running |
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