Audible Coolant Alarm w/ Idiot Light Option (1 Viewer)

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Lutz Auto

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I recently made an audible coolant alarm for my fzj80 with an option for a blinking idiot light. I currently have it programmed so that the alarm will sound when the coolant gauge needle starts hitting the edge of the red. A 12v led can be wired to the board which will blink as the alarm sounds. The led and alarm are independent, so you can have one, the other, or both.

The install is easy. We used ringlets to attach to the rear of the cluster to get 12v+, gnd, and signal without cutting or splicing any wires. We then mounted the board and alarm speaker to the inside of the dash with some velcro as shown in the photos.

This isn't meant to be a replacement for being attentive to the gauges, but may save an engine if the driver were to not be paying attention to the gauges. I know I have looked down at a climbing gauge at some point and wondered how long it had been that high before I caught it.

I wanted to post here to gauge interest and see if there are any suggestions before we go through with making some of these.



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Or, if you have a 95+, you can buy an UltraGauge and it monitors a LOT of other things and you can see actual temps in real time and set alarms at a given temperature.

If you have 91-94, then there are other alternatives.
 
Or, if you have a 95+, you can buy an UltraGauge and it monitors a LOT of other things and you can see actual temps in real time and set alarms at a given temperature.

If you have 91-94, then there are other alternatives.
Yes, I like the OBD2 aftermarket gauges like the UltraGauge and Scangauge. We even sell a fzj80 specific OBD2 touchscreen gauge that replaces the factory clock and has additional inputs for things that the OBD2 does not cover - like Trans Temp, Oil Pres, Outside temp, EGT, Boost, etc...

This audible alarm will work on 91-94 fj80s as well. This product will be more for people who want a factory look with added safety instead of (or even along with) aftermarket gauges.
 
I am watching this thread with interest --- I just paid almost 5K to replace an engine in a Honda Accord after my masters-degree-in-applied-mathematics daughter did not notice the temperature spiking

I really don't understand why all cars don't come with a buzzer that goes off when the temperature rises to a certain point.
 
I am watching this thread with interest --- I just paid almost 5K to replace an engine in a Honda Accord after my masters-degree-in-applied-mathematics daughter did not notice the temperature spiking

I really don't understand why all cars don't come with a buzzer that goes off when the temperature rises to a certain point.

I am not above making Honda parts too 🤣
 
I recently made an audible coolant alarm for my fzj80 with an option for a blinking idiot light. I currently have it programmed so that the alarm will sound when the coolant gauge needle starts hitting the edge of the red.
Consensus here seems to be that ‘edge of red’ on the factory gauge is already too late.
 
Consensus here seems to be that ‘edge of red’ on the factory gauge is already too late.
I was reading that. I will likely lower the threshold. I need to do some more testing to get the temp correct. I just chose beginning of the red because it was easy to test quickly. I can program any voltage threshold.
 
Definitely look into discussion on how the factory temp gauge is just a dummy light. If it starts to move up at all, you are already starting to overheat. I think it’s something like 226F, or that’s when the AC cuts out, or both? Maybe if you did the raventai mod to the gauge, which makes it react more accurately, your alarm would then also become more accurate and useful.

Either way, I like the idea. Good failsafe. I have a scangauge and keep my eye on it constantly out of habit, but you never know when you might miss something at the wrong time.
 
I'm in. This is something I've had on my to do list for a while. If I had done it earlier, my wife may not have turned my other engine into a pile of slag.
 
Yes, I like the OBD2 aftermarket gauges like the UltraGauge and Scangauge. We even sell a fzj80 specific OBD2 touchscreen gauge that replaces the factory clock and has additional inputs for things that the OBD2 does not cover - like Trans Temp, Oil Pres, Outside temp, EGT, Boost, etc...

This audible alarm will work on 91-94 fj80s as well. This product will be more for people who want a factory look with added safety instead of (or even along with) aftermarket gauges.
This thing is sweet! Wish I would have seen it before my gauge install lol. Might need to pick one up for the LX now.
 
I think it's pretty awesome!

Any chance in also getting a temp read out for those who want it?
I am working on a clock replacement for the early dash that uses external gauges. Hopefully that'll be shaping up pretty soon. I have all the hardware done, just need to motivate myself to write the code.
 
Definitely look into discussion on how the factory temp gauge is just a dummy light. If it starts to move up at all, you are already starting to overheat. I think it’s something like 226F, or that’s when the AC cuts out, or both? Maybe if you did the raventai mod to the gauge, which makes it react more accurately, your alarm would then also become more accurate and useful.

Either way, I like the idea. Good failsafe. I have a scangauge and keep my eye on it constantly out of habit, but you never know when you might miss something at the wrong time.
It seems like quite a few people have done that mod. If this product or going to support that mod for the coolant gauge, it would need to have two different calibrations One for the stock gauge setup and one for the mod which is not that big of a deal.

Anyone that has this mod done, want to do some quick testing for me? If so, shoot me a message. We'll work out a good deal.
 
@Lutz Auto -Prompting for product development- I’d like to have a turn key solution for low coolant sensor on the reservoir- or an inline flow & temp sensor. By the time the OEM temp gauge sensor has illuminated or needle risen towards the danger zone, it’s prob too late.
 
@Lutz Auto -Prompting for product development- I’d like to have a turn key solution for low coolant sensor on the reservoir- or an inline flow & temp sensor. By the time the OEM temp gauge sensor has illuminated or needle risen towards the danger zone, it’s prob too late.
I like this idea
 
For those of you worried that the alarm would be dependent on the narrow band factory gauge, this isn't the case.

The alarm works by using the sensor which has good resolution. I just need to find the perfect set point that never goes off under normal conditions, but is low enough to catch an issue.

The advantage of using the factory sensor is:
1: The install is super easy
2: You also still have a visual indicator tied to the sensor, so if the sensor fails, it would be easy to catch (ex. gauge stays very low all the time). With an audible alarm only tied to it's own sensor, you wouldn't know if the sensor had failed.

The circuit also uses a component to listen to the signal without modying it, so there is no change to the gauge when hooking the alarm up.
 

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