4104 Alarm Rectifier

mung · August 29, 2014, 10:20:02 AM

Does anyone have a schematic or instructions for changing the alarm rectifier to diodes with the correct polarity for negative ground? When I think of a rectifier I think of a bridge rectifier and from what I can see on the alarm rectifier it doesn't look anything like that.

Thanks,
Vern

chessie4905 · August 29, 2014, 11:50:11 AM

Since we didn't see any need for it in ours, we just removed it. The ammeter will work opposite.

bs4104 · August 29, 2014, 01:13:59 PM

This was in in FMCA June of 1981, hope this helps.
sent you a PM with the whole instructions

mung · August 29, 2014, 04:07:09 PM

Thanks!

mung · August 30, 2014, 01:43:47 PM

Well.....seems someone has changed things around on my bus. I don't seem to have the safety cutoff from the factory, which is understandable. My issue is that I have a rectifier similar to the safety rectifier that is hooked up to the telltale terminals on one side and a wire that goes into the great beyond on the other side. I am assuming that someone swapped out the alarm rectifier with this and who knows where the buzzer is, it sure wasn't making any noise when the low air light was on. So I am guessing that the best way to deal with that is to replace the rectifier with diodes as the instructions say, and maybe I need to put in a buzzer at some point.

eagle19952 · August 30, 2014, 03:20:04 PM

your wiring appears to not have been molested.... I like that when i see it...doesn't happen often ...

mung · August 30, 2014, 03:24:54 PM

Some of it has new wires run to replace others, but yes, he bundles look pretty good. I have some nice BBQ wires that were added at some point recently, so I have to figure out what those are and redo them in a way that they won't burn up again.

So, if I clip the one lead from the rectifier, can I start the bus with negative ground or will the missing alarm rectifier circuit cause me issues?

mung · September 03, 2014, 06:35:19 AM

So a little theory question about the alarm rectifier if anyone knows.

How is it a rectifier? Doesn't a rectifier convert AC to DC? That has always been my experience with them.

Based on the configuration of the diodes in the instructions for converting positive to negative ground it would seem to me that the purpose of the old "rectifier" and the new diodes is really DC blocking so that you can tie the signal that goes to the tell tale lights together into one buzzer. So if say the low air light is on the diode would allow that signal to pass through the diode but be blocked from feeding back to the other lights.

Am I missing something here?

Vern

mung · September 08, 2014, 07:03:31 AM

Here is the safety rectifier I built. I built a similar one for the alarm, but I need to put a buzzer in there since the buzzer is missing from my bus. I put connectors on the wires, so that I can pull it if I need to.

chessie4905 · September 08, 2014, 03:34:20 PM

I just purchased a couple of buzzers from Radio Shack and wired them into low air and overheat.

mung · September 08, 2014, 03:59:18 PM

cool.

eagle19952 · September 09, 2014, 11:15:24 AM

Quote from: chessie4905 on September 08, 2014, 03:34:20 PM
I just purchased a couple of buzzers from Radio Shack and wired them into low air and overheat.

get some for your turn signals....easy peasy, just wrap with electrical tape to turn the volume down.....

chessie4905 · September 09, 2014, 11:37:19 AM

Fix the cancelling mechanism in the turn signals if you can. Radio shack sells buzzers in different db ratings. (loudness)

mung · September 09, 2014, 11:42:04 AM

I am still trying to figure out how to wire the buzzer to my left arm.

eagle19952 · September 09, 2014, 11:48:45 AM

Quote from: chessie4905 on September 09, 2014, 11:37:19 AM
Fix the cancelling mechanism in the turn signals if you can. Radio shack sells buzzers in different db ratings. (loudness)

some don't have one....