12/09/22: Unfortunately, my plan fell apart when I tested the install. Only the high toned horn worked. The low didn’t even make a click. I was baffled. I retested each horn separately on 12 volts and both worked, loud but did work. I tried adjusting the low toned horn while in series but to no avail. I tried feeding the low first then the high (opposite to the way it was), again no joy.
The reason only one horn worked is because that high tone horn's electromagnet pulls its diaphram (the noise maker) and opens its switch before the low tone horn's electromagnet pulls its switch open. This happens because the hi-tone is designed to operate at a faster rate (higher tone). When either switch opens in your series circuit the spring in each horn will be pushing the diaphram back to its "at rest" position to close the switch and start the dance over again.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/13 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
The reason only one horn worked is because that high tone horn's electromagnet pulls its diaphram (the noise maker) and opens its switch before the low tone horn's electromagnet pulls its switch open. This happens because the hi-tone is designed to operate at a faster rate (higher tone). When either switch opens in your series circuit the spring in each horn will be pushing the diaphram back to its "at rest" position to close the switch and start the dance over again.
What baffles me is I did get them to work in series on my bench.
Phil Moderator, The Engine Shop, Interiors and Project Journals
What baffles me is I did get them to work in series on my bench.
Well, that sort of shoots down my theory.
The diaphragm (finally spelled it right) on the low frequency horn would be moving in your series electrical arrangement, but not far enough to make a LOUD noise before the high frequency horn's switch interrupts the current flow.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/13 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
The only difference between bench testing and the install, was the horns came with 10 gauge wire attached. I thought that was a bit of overkill since the original horn is wired with 14 gauge so I switched the feeds to 14 gauge.
Phil Moderator, The Engine Shop, Interiors and Project Journals
5/08/23: Today, after a long winter break, it was time to get back to working on our truck. The existing mirror installed on my truck, clearly didn’t belong there. Although period correct, it vibrated so badly, it was nearly useless. So to remediate the issue, I ordered a period correct, day/night mirror, with the correct mount for my truck from eBay and received it today.
Whomever installed the existing mirror, drilled two additional holes in the interior windshield trim, so me being me, couldn’t just leave those holes. I removed both sides and welded in the holes. In addition, I removed a few dents, straightened out a few areas them sanded and painted to match my interior. Their now hanging on my drying “Rack” waiting to be installed.
It feels great to get back to work on my truck!
Last edited by Phak1; Tue May 09 2023 01:04 AM.
Phil Moderator, The Engine Shop, Interiors and Project Journals
Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
Originally Posted by Gdads51
Phil,
Love the stair side drying/storage rack!
Me too!
Looks like it's multi-purpose. Good storage spot for your paint can/beer bottle opener.
Kevin Newest Project - 51 Chevy 3100 work truck. Photos [flickr.com] #2 - '29 Ford pickup restored from the ground up. First car '29 Ford Special Coupe Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
5/09/23: I finished installing my new day/night mirror. When I installed the inner windshield trim I noticed that the upper trim piece that covered the gap between the two trim pieces at the top of the windshield was missing. It was covered up by the old mirror so I never noticed it. I took a thin piece of aluminum and fabricated a new piece. I also re-bent the bottom trim piece to form it to better fit the contour of the mouldings.
It seems to be solidly mounted so I hoping the vibrating mirror goes away. Overall, I’m happy with the results.
5/10/23: I took our truck out for a spring run to get some gas for my mower and no more vibrating Mirror. A success!
Last edited by Phak1; Thu May 11 2023 12:28 AM.
Phil Moderator, The Engine Shop, Interiors and Project Journals
The finished product looks factory fresh, nice job.👍
Craig "Living life in the SLOW lane" Come, Bleed or Blister something has got to give!!! '59 Apache 31, 327 V8 (0.030 over), Muncie M20 4 Speed, GM 10 Bolt Rear... long term project (30 years and counting) '58 Viking 4400, 235, 4 Speed (Thor)
