Volvo Repair: Horn replacements, regina system, ground signal

Question
2nd follow up.  
I performed the electrical check.  At first i got 12VDC out of both wire connections but still no sounds.  Then i rechecked an got less than a volt (.4) moved wires thought the voltage reading appeared but nothing.  Checked eah wire indiviaually to ground then had the horn switches depressed got about 4 volts.  still no horns
thanks Art








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Followup To
Question -
I have a 92 740 wagon Regina system.  i just replaced the horns with "universal" replacements.  I've been having trouble with the connections to the horns for a while.  I replaced the connectors on the harness with crimp on "sta-con" connectors so they would fit up to the new horns.  this should have been an easy replacement you would think, but they do not sound any suggestions would be helpful
Thanks
Art
Answer -
first I would check for power to each horn the for a ground signal when the horn button is pressed.it could be bad horn buttons.

Answer
there should be power 12volts to the horns all the time.then on the other wire there should be a ground signal when the horn button is pressed.if no power could be bad fuse or wiring related if no ground signal to horns I would check the horn buttons or possibly a problem in the steering wheel area.