blower relay question

[matt reed 2]

My blower went out and I was fiddling with the relay.

I have an electric tester that you ground and then touch the wires to see if you are getting power.



Works on a few, but then when I put it in another terminal, it clicks on and the ac/heat works!

I took out that terminal, put a new connector on it and everything, but still the same issue.



sorry, i'm not too electrically informed. I don't want to short out the electrical system, but I don't want to spend $500 to repair something that seems really close to working.



any thoughts?

 

[EddieS'04]

Try one of the other relays of the same #. It could also be the resistor at the motor.

 

[matt reed 2]

thanks for the help, I think I'll have to end up getting ripped off at a repair shop though since I don't want to mess anything else up!

 

[Bill Koonce]

I'd spend the $15 or so to get one of those Chilton manuals that has schematics, at the very least. At least that way you'll know what you're touching. Then again, you'll need to be able to read schematics...but that's a skill that you need to work on your car's electrics. You might be able to tell what terminal is what if they're marked with letter codes.



If I were you, I'd buy an inexpensive DMM (digital multimeter) or other meter that has a "continuity check" setting. Apply 12V to the coil end, and use the continuity tester to see if the appropriate contacts close. (More advanced techs can use the resistance setting to see if the contacts are flaky.) There may be more than one circuit that the relay activates. There are also two basic conditions: normally open (NO) and normally closed (NC). NO contacts will close and complete the circuit when the coil is energized. NC contacts will be closed unless the coil is energized.



If this seems like Greek to you, use Google to find primers on basic electronics. They can probably be more helpful than me.

 

[matt reed 2]

thanks so much for the response! all advice is welcome and much appreciated.

 

[scott degroot]

The reason that the relay is clicking and turning things on is that the test light is actually providing a ground path for the relay and causing it to work. Your best bet is to put the test light away...funny how a $2.95 basic piece of test equipment can destroy a $1000.00 pcm by touching the worng wire. Get yourself a multimeter because about the only thing a test light tells you is that you can see a lightbulb when it lights up.