Checking the horn relay…

[SDMAN1981]

Hey I’m kinda having trouble with something, today I went to check the horn relay with a voltage meter and some small jumper wires but I noticed the relay itself had no diagram for the three prongs, so I was wondering how do you tell which wires of the voltage meter and the small jumpers go were?

I also viewed Eric’s video on testing a relay but he used a power probe and I don’t have one, so I have to resort to using a voltage meter and small jumper wires.

Thanks.

Topic

[Charles]

The horn uses +12 volts and the horn switch supplies ground. If you measure voltage between one of the socket terminals and the positive battery post you should see +12 when you press the horn button on the steering wheel. This will be the negative coil of the relay. Then measure from the negative battery post to the other two socket terminals. The one that reads 12 volts is the source voltage and the positive coil of the relay. The remaining terminal in the socket goes to the horn.

[college man]

check the bottom and sides of the relay for markings.if none
found.use an ohm meter to find the two connections that show
resistance.

[SDMAN1981]

OK, did that and it put out 47 ohms, so then I also hooked it up to 12v (battery) and heard it ‘click’ and put the two probes from my voltage meter on it as well then it blinked zero….

[EricTheCarGuy]

Sounds like the relay is fine. With horn problems the first place I always go is to the horn itself. I check to see if there is a 12v feed when the horn button is depressed. If you see the 12v feed when the horn button is depressed then the horn is bad. Replace it and recheck.

[Author]

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