Federal Signal Touchmaster TM4 Light issues

Lennyboi226

Member
Nov 26, 2023
29
4
Florida
Hello, I have a Federal Signal Touchmaster TM4 and I am having an issue with the lights on it. For some reason the "Siren" light is constantly blinking with no click sound and no switches activated. And all four lights oddly flicker when any of the sounds on the system are activated. This system is in great condition and everything worked on it when I first got it about a year ago. Also when aux is activated the ACC light comes on but there's no clicking sound. Any info on the issue is much appreciated

 
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Hello, I have a Federal Signal Touchmaster TM4 and I am having an issue with the lights on it. For some reason the "Siren" light is constantly blinking with no click sound and no switches activated. And all four lights oddly flicker when any of the sounds on the system are activated. This system is in great condition and everything worked on it when I first got it about a year ago. Also when aux is activated the ACC light comes on but there's no clicking sound. Any info on the issue is much appreciated

(just an FYI i have all positive wires in the back going to one line, with the rls and horn ring bypassed by a connected wire as it should be)
 
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(just an FYI i have all positive wires in the back going to one line, with the rls and horn ring bypassed by a connected wire as it should be)
First step is to test it out of a vehicle on a known good ground and power source. There are too many variables otherwise. A lot of times a bad ground or insufficient voltage can cause weird behavior, but you need to isolate everything.
 
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First step is to test it out of a vehicle on a known good ground and power source. There are too many variables otherwise. A lot of times a bad ground or insufficient voltage can cause weird behavior, but you need to isolate everything.
So at the moment, I have it hooked up to a 110v to 12v converter with alligator clips. I had the black wire connected to the negative, and the 3 red wires and white wire hooked up to the positive. I had extended the cables on the back of the siren box with smaller gauge wire which I cut off completely to make sure that wasn't causing the issue. After having the raw wires hooked up I noticed that the lights would no longer flicker when the siren was activated but still get slightly dimmer along with the clicking mechanism stopping. Also, the Siren light is still constantly blinking with no clicking even when the system is off but getting power. (BTW the wall power setup I'm using now is the same one I used a year ago when it worked perfectly fine).
 
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Can you describe in detail exactly what you mean when you say 110v to 12v converter, please?
The one thing I suspected was that it was a possible amp issue. I have the system going to a 100-watt siren speaker.
 

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The pictured switch-mode power supply almost certainly cannot supply sufficient amperage. You will need a much stouter power supply.
 
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For the siren alone, 100 watts at 12 volts, nominal, is 8.33 amps. There are various losses to account for, so a 12 volt power supply rated for 12 amps, continuous duty, is probably about the bare minimum that would suffice.

I typically recommend using a sealed lead acid battery instead of, or in addition to, a power supply. Using a battery in parallel helps to smooth out some of the impurity produced by a switch-mode power supply. Additionally, a battery can better tolerate instantaneous demands for relatively high current compared to a power supply.
 
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For the siren alone, 100 watts at 12 volts, nominal, is 8.33 amps. There are various losses to account for, so a 12 volt power supply rated for 12 amps, continuous duty, is probably about the bare minimum that would suffice.

I typically recommend using a sealed lead acid battery instead of, or in addition to, a power supply. Using a battery in parallel helps to smooth out some of the impurity produced by a switch-mode power supply. Additionally, a battery can better tolerate instantaneous demands for relatively high current compared to a power supply.
Ok that sounds good. I appreciate the help!
 
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I would add that if you don't use batteries you need a regulated power supply such as the ones designed to power radios indoors. Depending on the setup and need to charge batteries a power supply can be a better choice. Regardless, as others have said your current supply is not going to work for a variety of reasons, mainly the amp draw. I won't test a siren or switchbox with less than a 20 amp regulated supply. Most sirens are fused at 10 or 20 amps, that's generally 110% of their peak draw.
 
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I would add that if you don't use batteries you need a regulated power supply such as the ones designed to power radios indoors. Depending on the setup and need to charge batteries a power supply can be a better choice. Regardless, as others have said your current supply is not going to work for a variety of reasons, mainly the amp draw. I won't test a siren or switchbox with less than a 20 amp regulated supply. Most sirens are fused at 10 or 20 amps, that's generally 110% of their peak draw.
OK I will definitely look into that.
 
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OK I will definitely look into that.
This is a very affordable higher amp one

If you search Amazon or other places you want at least 20 amps and regulated. These are often marketed as "ham radio power supply" or similar. If you get a battery charger or other device it will be cheaper, but you need to put a 12v battery inline with the device to "clean up" the power. The radio supplies are designed to not damage sensitive electronics whereas the chargers are designed to simply dump 12vdc power more or less.

Here is my power cart for lightbars.
 
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This is a very affordable higher amp one

If you search Amazon or other places you want at least 20 amps and regulated. These are often marketed as "ham radio power supply" or similar. If you get a battery charger or other device it will be cheaper, but you need to put a 12v battery inline with the device to "clean up" the power. The radio supplies are designed to not damage sensitive electronics whereas the chargers are designed to simply dump 12vdc power more or less.

Here is my power cart for lightbars.
Yeah, I have it hooked up to an actual 12v DC battery and it's still having the same issues. There must be an issue with the system.
 
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Yeah, I have it hooked up to an actual 12v DC battery and it's still having the same issues. There must be an issue with the system.

There could be.... how much have your connected? Usually I start with removing all outputs and just connecting power and ground. Then I start reconnecting the outputs if it doesn;t screw up with just power and ground. It's a failure state I haven't seen, but that doesn't mean much. If you are just getting rid of it I'd pay shipping to have a go at fixing it.
 
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There could be.... how much have your connected? Usually I start with removing all outputs and just connecting power and ground. Then I start reconnecting the outputs if it doesn;t screw up with just power and ground. It's a failure state I haven't seen, but that doesn't mean much. If you are just getting rid of it I'd pay shipping to have a go at fixing it.
I've tested each wire and it seems that the one out of the four that mainly powers the system causes the light to come on and flash when nothing is activated, it's sort of hard to explain since there's so much going on with the lights at once but yeah. It's the second-to-biggest red wire (of which there are 2) which powers the lights on the system and causes this weird state. I would like to either keep this system or at least find a new Touchmaster (preferably an original Dunn-Bar one) to use on a future prop car I have planned.
 
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There should be 3 large wires. A 10g, a 12g, and a 16g. The 10g (largest) powers the 3 position switch. The 12g powers the siren and other items, the 16g is an ignition trigger. It sounds like it's the 12g, which is the main siren and non-slide switches.

So I understand correctly; There is nothing else attached and when you power the middle sized wire the siren light flashes?
 
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There should be 3 large wires. A 10g, a 12g, and a 16g. The 10g (largest) powers the 3 position switch. The 12g powers the siren and other items, the 16g is an ignition trigger. It sounds like it's the 12g, which is the main siren and non-slide switches.

So I understand correctly; There is nothing else attached and when you power the middle sized wire the siren light flashes?
Yeah, it's just the one wire that powers the lights on the slide switch that makes the red light turn on and flash. Doesn't change at all when any other wires are powered or not.
 
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Yeah, it's just the one wire that powers the lights on the slide switch that makes the red light turn on and flash. Doesn't change at all when any other wires are powered or not.
The middle sized wire is not the 3 position switch, that's the biggest wire. Regardless, that red light flashing means the unit is receiving an input that will activate the siren.

tm.png

There are a lot of variable with these as far as triggering, allowing, and locking out the siren. Can you do a video with the unit hooked up to the battery? The first video was shot with it hooked up to the insufficient power source correct? That would account for the other odd behavior, but not the red siren light.
 
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The middle sized wire is not the 3 position switch, that's the biggest wire. Regardless, that red light flashing means the unit is receiving an input that will activate the siren.

View attachment 251657

There are a lot of variable with these as far as triggering, allowing, and locking out the siren. Can you do a video with the unit hooked up to the battery? The first video was shot with it hooked up to the insufficient power source correct? That would account for the other odd behavior, but not the red siren light.
Yeah, it was. I will have to extend the wires on it so I can film a video with the battery. I will get a new video here probably in a couple of days or so.
 
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Yeah, it was. I will have to extend the wires on it so I can film a video with the battery. I will get a new video here probably in a couple of days or so.
Great! I will try to dig up the other info I had when I last troubleshot one of these for a similar issue.
 
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Great! I will try to dig up the other info I had when I last troubleshot one of these for a similar issue.
Yeah, I don't know what's going on with it. Everything is functional but it's just that light having issues. It's not a power problem because I hooked it up to higher-rated power supplies and it's just not changing. I will probably keep it for now and might sell it in the future. It sucks cause it's in perfect condition for its age but man that light thing won't go away. Hopefully, if I do sell it it goes to someone who can figure out the problem with it. I'm planning on possibly looking for a Unitrol 480k or a Dunnbar-Nunn Touchmaster in the future.
 
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