How to test a relay?
10-01-2010, 05:27 PM
#41
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Re: How to test a relay?
You guys lost me. I touched up all the solder on the circuit board, I'll try putting it back in in a few.
EDIT: well, that accomplished nothing. Never does work when I try re soldering.
EDIT: well, that accomplished nothing. Never does work when I try re soldering.
Last edited by marlinspike; 10-01-2010 at 05:48 PM.
10-01-2010, 05:41 PM
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Re: How to test a relay?
No, a partial short to ground would only show voltage when the switch was on. It would show zero volts when the switch was off, because there would be no path for power to enter the circuit and be shorted to ground.
10-01-2010, 05:46 PM
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Re: How to test a relay?
I believe that's 6 and 12 on the switch harness, looking at the schematics..
Last edited by Fabrik8; 10-01-2010 at 05:49 PM.
10-01-2010, 06:15 PM
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Re: How to test a relay?
Yeah, in that case, he could have nothing going to the switch, and a partial short to power. But I only believe half of what someone tells me. He said it has 0 when off, and 8.xx when on. Of course, the switch may be stuck on, etc. But overall, I've learned to take it with a grain of salt. (Real world measuring the crap after other techs who thought they had it, didn't, then wonder where they messed up!)
10-01-2010, 06:18 PM
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Re: How to test a relay?
I think I was misunderstood. I show 0 volts when the CAR is off. When the car is on I see 8.275V no matter which pushbutton unit button is pushed (even the off button).
10-01-2010, 06:27 PM
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Re: How to test a relay?
And that could indicate a bad control unit, or the control unit feed and output wires shorted together.
Test point is to pull the panel, see what the input wire has for voltage. If it's 12V, and the output to the relay doesn't change regardless of A/C bing on or off, then I'd say the Control Unit is dead. As Fabrik8 pointed out. If you have 8.xx coming into the control unit, then you need to figure out why it's not going off (which could be due to the lowered voltage.) That could indicate a short to ground on the feed, or a short to the relay wire. Or any number of other things still.
Test point is to pull the panel, see what the input wire has for voltage. If it's 12V, and the output to the relay doesn't change regardless of A/C bing on or off, then I'd say the Control Unit is dead. As Fabrik8 pointed out. If you have 8.xx coming into the control unit, then you need to figure out why it's not going off (which could be due to the lowered voltage.) That could indicate a short to ground on the feed, or a short to the relay wire. Or any number of other things still.
10-02-2010, 06:01 AM
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Re: How to test a relay?
OK, who wants to explain this one.
At the plug for the push button unit I get 14V
So I tried jumping across the pins and...still get 8.2V at the relay
So I tried removing the jumper (i.e. nothing connecting the pins) and I get...8.2V.
So basically any time the car is running the relay gets 8.2V, even with the push button unit out of the car.
At the plug for the push button unit I get 14V
So I tried jumping across the pins and...still get 8.2V at the relay
So I tried removing the jumper (i.e. nothing connecting the pins) and I get...8.2V.
So basically any time the car is running the relay gets 8.2V, even with the push button unit out of the car.
10-02-2010, 10:27 AM
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Re: How to test a relay?
OK, who wants to explain this one.
At the plug for the push button unit I get 14V
So I tried jumping across the pins and...still get 8.2V at the relay
So I tried removing the jumper (i.e. nothing connecting the pins) and I get...8.2V.
So basically any time the car is running the relay gets 8.2V, even with the push button unit out of the car.
At the plug for the push button unit I get 14V
So I tried jumping across the pins and...still get 8.2V at the relay
So I tried removing the jumper (i.e. nothing connecting the pins) and I get...8.2V.
So basically any time the car is running the relay gets 8.2V, even with the push button unit out of the car.
