Horn wiring problems

[qwik1320]

My horn had been working intermittently last year but now does not work at all.

The horn definitely works (touched a jumper from the hot side of the battery to the horn), ground is good (took everything apart and re-sanded all the connections). When I put a meter in series instead of the horn I get ~11.8V when I press the horn button. I get ~12.6V if I hook the meter directly to the battery. I cleaned the contacts on the horn and the power wire and it didn't help.

I do hear the relay clicking when I press the horn button (I never heard the relay click in the past but then again when I pressed the button the horn blew).

If the relay were bad I would have figured I wouldn't get any voltage at the horn. Any ideas?

[qwik1320]

Any one have any ideas? How can I check to see if the relay is working or not? Need to have it fixed for inspection next month.

If I can't get it working I might have to get a set of those horn blasters :naughty:

[qwik1320]

Just following up in case someone searches this problem in the future. It was the horn relay, the voltage was passing but not enough current for the horn to blow. The guys at nastyz28 helped me out.

For all you 72/73 chevy owners, the same horn relay was used on every vehicle model and this horn relay is now discontinued. It is GM p/n 3996283. No luck finding one locally but Specialty Parts Warehouse in AL (334-493-1240) hooked me up with a new one they make. It looks identical to the original, $42.50 shipped to my door. Shipped fast and work great.

[Madspeed]

Qwick your allost on the right track with you DVOM
you dont want to put the volteter in series
You allost had a voltage drop test. and had you done it right youd have found the relay was bad
when doing a voltage drop test you are using a live curcuit to test actual resistance in the curcuit between your volteter leads.

How to do a voltage drop test
what you are looking for is resitance in a connection or circuit.
here is what you do
(this test is for a dirty batt connection)
Pu your DVOM on the 0 to 20 volt scale put the red lead of the voltmeter on the actual Battery post and the negative lead of the voltmeter on the actual battry cable terminal With the headlights on ENG OFF ( if the eng is running the test will be invalid) Now you want to read the voltage anny voltage you read is actually voltage lost throught the connection ( IE resistance fro loose or dirty connection) 1 to 2 vlts is ok annything more is not you should clean the terminals and retighten them

now for you horn you would put red lead from tester to the batt post and the blk lead to the horn terminal read the voltage (with the relay activated of course) if its more than 1 to 2 vlts you need to start working the Black test lead backwards towards the batery to find your resistance
Hope I didnt confuse you.

Gl Ken F

[qwik1320]

Thanks Ken, helpful tips for the future :cool: