instrument cluster voltage limiter

guzzimike said:

I was looking at this retrofit Solid State Voltage Limiter for my Dart.

It's Plug and Play, which works best for me as the dash is in use...


http://www.rt-eng.com/mediawiki/index.php/RTE_ABlimiter

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Hey what year dart do you have? Do you have photos of your instrument cluster with the IVR4 or 3

I have bought them for $30 on ebay. By tweaking the output voltage, I could get my temperature gage to read perfect. Of course, need another "knob" to get the fuel gage also correct, so I installed series resistors on the back of the cluster for that. I also tweaked the slotted needle adjustments in one or both gages (careful not to break).

For those suggesting "why not just 12 V sensors?", would you really want 12 V on the fuel level sender in your fuel tank? That is 6x more power available and much more spark potential. I know the gas vapors should displace air, but investigators think one airliner (Swiss-Air from NYC, I recall) exploded due to a frayed wire in the fuel tank.

I've tried using both a 7805 and a variable one calibrated to 6.0 volts output. I find what's needed is exactly 5.0 volts so I simply use the 7805. I test my gauges on the bench using an 11 ohm resistor (exactly) in series, I find it works well. As stated above, you need a heat sink for the 7805 or it won't last long at all. Mine is not a higher current device and has lasted for over 3 years now (with a heat-sink) but it is a good idea to use the one rated for more current.

glhx said:

I'm bringing this back for a question.

I ran the 7805 set up years ago. Never drove the car much to see how. Accurate it was. I was just happy to have the gas gauge back working.

I ordered some 7805s. Should be here in a few days.
However......

I can get a 7806 6 volt output right now. What will this do?
Make the gauge more accurate?
or make the gauge and burn it out over time?

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The 7805 isn't exactly 5.0 volts. Even though its a modern solid state piece it aint everything some think it is. At 68 degrees, initial output should be 4.86 to 4.92 . As it warms it'll climb to 5.2 for a normal/average and all those numbers vary slightly with mfgr. It can go 5.4 and more depending how hot it gets. Digikey once substituted the brand I had ordered with some other brand. initial output was in the 4.6s. Yeah, Digikey got a message. In any case, Efficient heat sink is a must.