How to Install a Budget Digital Universal Speedometer/Tachometer

[ThanasisPolitis]

If you're looking to upgrade your kit car dashboard with a budget-friendly digital speedometer/tachometer, this guide is for you.

I recently installed a basic Chinese universal speedometer/tachometer, and while the instructions were less than helpful, I've managed to get it working perfectly. Here's how you can do it too. 

Where to Buy 

I purchased my dashboard from eBay for around £30. Similar models are available on AliExpress and other online marketplaces. 

• AliExpress Speedometer
• eBay Universal Speedometer

 

Issues and Solutions 

1. Water Temperature Sensor 

The manual specifies a 900-80 Ohm sensor (Cold-Hot), but this didn't work as expected. At ambient temperature (20°C), the dash showed 2 out of 5 bars, and at 85°C, it maxed out all bars. 

Solution: 

• Use a resistor in series with the sensor to increase the resistance. 
• Calibrate by using the sensor that gives a maxed-out reading at operating temperature, then adjust with a resistor until the dash shows 3 out of 5 bars. 

 

2. Fuel Sensor 

The manual calls for a 0-90 Ohm sensor, which can be hard to find. Most available sensors are 0-190 Ohms, which won't work correctly. 

Solution: 

• Purchase a 0-90 Ohm sensor that fits your tank. I found one on eBay: 
  • 0-90 Ohm Fuel Level Gauge Sender

 

3. Speed Sensor 

The kit includes a magnetic speed sensor but mounting it can be tricky. 

Solution: 

• Use a Brantz Motorsport Speed Sensor, which connects to the gearbox speed cable and sends out 4 pulses per rotation to the dash. This allows you to calibrate the digital dash to match your original speedometer. 
  • Brantz Motorsport Speed Sensor

 

Installation Tips: 

Water Temperature Sensor: 

• Install the sensor as per the manual. 
• Use a multimeter to measure the resistance at different temperatures. 
• Add a resistor in series to adjust the resistance until the dash displays correctly. 

 

Fuel Sensor: 

• Ensure the sensor fits your tank. 
• Test the sensor before installation to confirm it works correctly with the dash. 

 

Speed Sensor: 

• Attach the Brantz sensor to your gearbox speed cable. 
• Use a cordless drill to simulate speed and calibrate the digital dash to match your old speedometer. 

 

Wiring Matrix:

Final Thoughts 

After overcoming these issues, my new digital dashboard is fully operational and looks great. I hope this guide helps anyone else looking to upgrade their dashboard with a budget digital speedometer/tachometer. 

Feel free to ask any questions or share your own experiences! 

 

 

Edited August 2, 2024 by ThanasisPolitis

[Foz]

Looking good & a very useful write up. 

If it was my car I think I might have to go for a slightly larger steering wheel