Solid State Rallye Gauge Instrument Voltage Regulators (IVR)
I wanted to replace my stock IVR with a safe and reliable solid state IVR, but didn't want to pay $50 or more for a pre-made unit. So I built my own. Since I needed to order multiples of the required parts, I made several of them. I am an EMC Engineer by trade, so I thought maybe I could save others the trouble. If you want to make the same conversion, I'm offering them for $25 including USPS First Class postage anywhere in the continental US. I accept PayPal or Venmo (friends and family - you pay the extra fees if you want buyer protection).
They are constructed with a L7805CV 5V regulator, a 47uF electrolytic capacitor, and a finned heat sink. They will accept up to 35VDC, output a steady and reliable 5V (up to 1.5A), and the transistor has thermal overload and short circuit protection.
I will leave the leads long and include ring terminals so you can choose your mounting location.
But the most logical place to mount it is in place of the stock radio noise filter.
All were thoroughly bench tested after construction at 13.84VDC input and have a solid 5VDC output that will feed a smooth signal to the fuel, oil, and temp gauges using the factory PCB traces.
I will include comprehensive instructions with detailed pics for doing the modification and installation, but - full disclosure - it requires opening and modifying the stock fuel gauge, as that is where the archaic points-type stock IVR circuit lives. But the same mod is required if you install a store-bought unit. It is not difficult, but requires patience and care. I've done this mod on several A body rallye cluster assemblies and have had nothing but good results. No more worries about smoking your gauges by over-feeding them 12 volts. There are several threads in the FABO archives that describe the mod if you want to do some searching, or feel free to message me with questions. This is intended for rallye clusters, but can be adapted to a stock cluster with the plug-in IVR (you would do the mods though).
Here are some pics of my most recent cluster modified using this device being bench tested with a 12V power supply and a custom resistor box to supply LOW - HALF - FULL resistance values.
I wanted to replace my stock IVR with a safe and reliable solid state IVR, but didn't want to pay $50 or more for a pre-made unit. So I built my own. Since I needed to order multiples of the required parts, I made several of them. I am an EMC Engineer by trade, so I thought maybe I could save others the trouble. If you want to make the same conversion, I'm offering them for $25 including USPS First Class postage anywhere in the continental US. I accept PayPal or Venmo (friends and family - you pay the extra fees if you want buyer protection).
They are constructed with a L7805CV 5V regulator, a 47uF electrolytic capacitor, and a finned heat sink. They will accept up to 35VDC, output a steady and reliable 5V (up to 1.5A), and the transistor has thermal overload and short circuit protection.
I will leave the leads long and include ring terminals so you can choose your mounting location.
But the most logical place to mount it is in place of the stock radio noise filter.
All were thoroughly bench tested after construction at 13.84VDC input and have a solid 5VDC output that will feed a smooth signal to the fuel, oil, and temp gauges using the factory PCB traces.
I will include comprehensive instructions with detailed pics for doing the modification and installation, but - full disclosure - it requires opening and modifying the stock fuel gauge, as that is where the archaic points-type stock IVR circuit lives. But the same mod is required if you install a store-bought unit. It is not difficult, but requires patience and care. I've done this mod on several A body rallye cluster assemblies and have had nothing but good results. No more worries about smoking your gauges by over-feeding them 12 volts. There are several threads in the FABO archives that describe the mod if you want to do some searching, or feel free to message me with questions. This is intended for rallye clusters, but can be adapted to a stock cluster with the plug-in IVR (you would do the mods though).
Here are some pics of my most recent cluster modified using this device being bench tested with a 12V power supply and a custom resistor box to supply LOW - HALF - FULL resistance values.
