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Old 03-04-2024, 02:22 PM   #1
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Testing SAI pump, I think I killed it

I’m trying to test the components in my SAI system. I wanted to test my SAI pump so I hooked it up to a 12v battery. It made a little noise then nothing. Was it already dead or did I kill it?

There are videos on YouTube that show hooking the pump to 12v to test its operation. Hooking up a 12v DC motor to 12v shouldn’t kill it, should it? It’s been a while since my EE theory classes in college. So I need a 12v power supply where I can vary the amps to properly test the SAI pump?

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Old 03-05-2024, 02:20 AM   #2
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Assuming that your 12V battery isn’t bad (measure the voltage across the terminals while it’s under load), then I’d say you have a bad SAI fan motor. You don’t need a current limited power supply for a simple motor like that.
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Old 03-05-2024, 03:16 AM   #3
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First thing to do is check to see if you blew a related fuse.
Then check the motor for continuity.
if those are good then the motor should run when hooked up direct to 12v.
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Old 03-05-2024, 04:30 AM   #4
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Thanks! Just the answers and advice I was hoping for.
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Old 03-05-2024, 09:51 AM   #5
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I took another look at the leads that I'd used to test the SAI pump--the 7.5amp fuse had blown. I replaced the fuse with a piece of 20ga wire and the pump spun right up.

Last night after I thought the pump was dead, I tore it apart to determine the cause of death. I put it back together this morning after discovering the blown fuse, so that I could test it. It sounds okay, no screeching, but I'm going to go ahead and order new bearings since these are 20 years old with 80,000 miles on them.

I'm also debating replacing some other SAI parts, anything less than $50, since I already have everything torn apart.
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Old 03-05-2024, 11:18 AM   #6
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Quote:
Originally Posted by woodgeek View Post
I took another look at the leads that I'd used to test the SAI pump--the 7.5amp fuse had blown. I replaced the fuse with a piece of 20ga wire and the pump spun right up.

Last night after I thought the pump was dead, I tore it apart to determine the cause of death. I put it back together this morning after discovering the blown fuse, so that I could test it. It sounds okay, no screeching, but I'm going to go ahead and order new bearings since these are 20 years old with 80,000 miles on them.

I'm also debating replacing some other SAI parts, anything less than $50, since I already have everything torn apart.
That pump only spins up for a few seconds at cold startup.
Most likely uses sealed bearings
Very unlikely that the bearings are worn.
The car may have 80,000 miles on it but the SAI pump has very little use on it.
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Old 03-05-2024, 04:51 PM   #7
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The plot thickens. My SAI pump works. I checked the 40a fuse, it’s good. I hooked up my scan tool and initiated a test of the SAI pump. I heard the relay click but the fan didn’t turn on. I checked voltage at the pump connector and got nothing.

Can a relay click and still be bad?
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Old 03-06-2024, 03:06 AM   #8
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Quote:
Originally Posted by woodgeek View Post
The plot thickens. My SAI pump works. I checked the 40a fuse, it’s good. I hooked up my scan tool and initiated a test of the SAI pump. I heard the relay click but the fan didn’t turn on. I checked voltage at the pump connector and got nothing.

Can a relay click and still be bad?
Just tell us that you're not replacing fuses with a piece of wire. Tell us it was simply a diagnostic measure, and that you returned to the fuse setup.

Thanks.
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Old 03-06-2024, 03:26 AM   #9
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�� no, I’m not that reckless ��. The only fuse I replaced with wire was the one in the lead between the 12v battery and the SAI pump. I didn’t have an extra 40amp fuse to test the pump.

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