Hi guys had a question so I worked on a ford that had a brake fluid low light on it showed a resistor in the ground side of the switch. would the test light method still be safe to do to pull the circuit down? already diagnosed the car just was curious for future reference.
Do you mean use the test light to apply ground to the circuit to see if the brake warning lamp on the instrument cluster illuminates?
Then I think yes. There's not much I won't put my test light on...
If you wanted to post a screenshot of the diagram as well as the year, make and model it would help to understand what you're dealing with
Thanks for getting back with me. Sorry for the late response. so it was a 2012 ford edge with a 3.5l. So when I was diagnosing it I wanted to see if maybe it was a bad brake fluid switch but wasn’t sure it would be safe for the computer pulling the two wires to ground with it showing a resistor in the switch. Also would there be any by pass test I could have ran at the connector?
had no voltage on either computer wires. I figured out it was a broken wire only reason I posted the question is I always try and think after a diagnosis if I should have done anything differently. Thanks for your time.
Thanks for clarifying. I would try it with the test light. It might set a circuit short ground with the test light in the circuit, but I doubt it would actually hurt anything.
If nothing else, a short circuit code would be a good indication that the circuit is intact.
Just out of curiosity, which wire was broken? You said there was no voltage on either wire. That suggests to me that one wire is fed a reference voltage that returns to the computer on the other circuit as a continuity check.
Also, what is the reference voltage level on that circuit?
Not trying to badger you, glad you got it figured out, just curious.
Hope you had a great Christmas!
Ok thanks. Ya it’s hard sometimes you don’t know a test is safe until you’ve tried it. I’m sure I’ll toast a module at some point but I try my best not to. Ya I think it does send a reference voltage to verify it doesn’t have any broken wires. I think it was the pink wire I was able to jump the two wires at the bcm to verify what I was thinking that it had a broken wire and it shut off the light. It had 11v it was kind of weird it had a broken wire at the fire wall about 2in before it went into the main harness loom was all intact no visible damage. I don’t feel badgered. I hope you had a great Christmas too. I really appreciate everything you guys do with the ScannerDanner training. I’m actually starting to enjoy diagnostics it’s fun when you can figure it out fairly quickly and make some money. It’s no fun when you have very little idea where to go on a diagnosis.
It’s no fun when you have very little idea where to go on a diagnosis.
This is true, but working through that challenge and coming out with the win is just about the best feeling you can get working on cars.
That and when you can finally exhale after the engine you had in a million pieces a few hours ago fires up and runs perfect.
had no voltage on either computer wires. I figured out it was a broken wire only reason I posted the question is I always try and think after a diagnosis if I should have done anything differently. Thanks for your time.