Temp Gauge Warning Idiot Lamp

[Captain Obvious]

On my last drive of this past driving season, my engine overheated. It wasn't intended to be the last drive, but unfortunately that's how things worked out.

The failure was a split in one of my engine compartment coolant lines and I lost most of the coolant. I didn't know anything was wrong until it was too late. I never noticed the temp gauge creeping up and I didn't know there was any problem until I saw wisps of steam while sitting at a traffic light. And by that point, it was too late... The coolant was gone, the engine was overheated, and the temperature gauge was pegged hot.

It became clear that even though I believed I scanned my gauges frequently, it wasn't good enough. I needed a solution that got my attention. With that in mind, I decided to modify the gauge to add a warning lamp in addition to the gauge needle. The "Idiot light modification."

Here's the faceplate for the temp/oil gauge. There is plenty of room on the right hand side to put an indicator light. First thing is to make sure it doesn't interfere with the needle. I put a piece of tape on it and marked the needle position at full scale and then marked where I could put an LED to use as an indicator such that it wouldn't interfere with the needle. The black dot above the "0" is where the LED will go:

Drill the hole in the faceplate and insert an LED from the back side:

Here's the front side with the LED in place:

And here's the gauge reassembled with the warning light off:

Warning light on:

I haven't built the final version of the driver circuit yet, but just to test the idea, here's a video of proof of concept:
https://youtu.be/itjYR885iik

I will take some final pics after the drive circuit is worked out and the gauge is in the car. Here's to hoping this will get my attention if I ever have problems again!!

[Patcon]

Any problems with the cylinder head? Let me know if you need anything. I have a few laying around if you were to need one...

[Mark Maras]

 I dislike idiot lights because they replaced analog gauges. However, this is a great idea. Have you considered one for the oil pressure too, "while you're in there"?

[Zed Head]

I've often thought that idiot sounds would be better.  We have idiot sounds for the lights and the key in the ignition.  A couple more sounds for temperature and charging, plus the lights to indicate which problem, and the odds of surviving it increase.

How about a cylinder killer, like they use on the newer cars?  Kills injection for half the cylinders to drop the heat load.  

[Chickenman]

Now this is a warning light:

[siteunseen]

1 hour ago, Zed Head said:

I've often thought that idiot sounds would be better.  We have idiot sounds for the lights and the key in the ignition.  A couple more sounds for temperature and charging, plus the lights to indicate which problem, and the odds of surviving it increase.

How about a cylinder killer, like they use on the newer cars?  Kills injection for half the cylinders to drop the heat load.  

I like that idea too.  If he could wire it in with that horrible buzzing when the key is first turned on he could keep looking at the cute joggers, bird dogging.

Great work Captain, your winter down time is always neat to see.

[Chickenman]

One of the nice features on my Audi is a Beeper that goes off for 5 seconds if any dash warnings come on. Like Low fuel,  Temperature etc. It's really handy, especially if it's a brights unny day and you have sun glasses on. You may not notice the dash light, but the beeper draws attention to the problem. 

[Captain Obvious]

Thanks guys!

I did consider an idiot sound as well, but I didn't think I would hear it. Windows down, exhaust singing, valves-a-clickin, and the radio playing 80's hair metal at volume 11. No way I was gonna hear a beeper. I figured that the flashing warning lamp would catch my eye even in my peripheral vision. I won't know until the spring how it looks on the road though.

I'm also considered wiring it into the oil pressure as well. It would be a pretty addition at this point. I'm torn between sharing the same warning lamp for both functions though. It would certainly be easy to discern which of the two faults caused the lamp to come on, but it would sure be more glamorous to have one for each gauge.  

 

[Captain Obvious]

9 hours ago, Patcon said:

Any problems with the cylinder head? Let me know if you need anything. I have a few laying around if you were to need one...

Thanks bud. I don't really know yet. I was close to home when I noticed the problem and managed to coast 90% of the way to my garage with the engine shut off. I let it cool off in the driveway with the hood up, and then after it was cool, I started it and put it away. It started and ran fine, so I'm hopeful I didn't cause any permanent damage. I'll do a compression test in the spring. I appreciate the help, and I'll keep you posted!

I've got an F54/P79 motor here that I've been meaning to drop in...

[Patcon]

No problem

[Chickenman]

Our MCI Tour Buses had a 100 DB " Sonalert " for low air pressure. That will get your attention fast. Often used on Race cars.

Mallory's " Specialty Sounds :  " Piezo series has 15 various sounds, so you can have individual alarms for level of severity or function. All the way from Bird Chirps and Warbles to Police Sirens. 

http://www.mallory-sonalert.com/AVBySeries.aspx

Edited January 15, 2018 by Chickenman