I’m putting a PMU in my Jaguar MK10 1965 and I’d like to stick to using the original temp and fuel gauges in the car which operate on the resistance value from the original senders. Is there a way to output this from the PMU? After reading I don’t think there is a way to output an analog signal with variable resistance but thought I’d ask in case anyone else has done this or found a work around. Many thanks, Marko
I am guessing it has the engine swapped and no OEM sensors?
What about the fuel level sensor? The OEM sensor is also changed?
The gauges are directly measuring voltage.
The resistance measurement is indirect by using a voltage divider circuit.
The variable resistance can be replaced with variable DC voltage.
One solution is to mount the OEM temperature sensor as an additional sensor just for the gauge.
Another solution is to use PWM output to create DC voltage with the low-pass RC circuit. You would have to use 25 A output since only those outputs have PWM capability.
Hello, thank you so much for this information. Well the engine has been swapped for a Jaguar V12 and I’ve just fitted two turbos. It’s already running an Emerald stand alone ECU so I’ll send the can data from that to the PMU. I’m fitting new temp sensors for the charge cooling circuit and also to monitor the temp of the water coming out the turbos cooling circuit. So it’s basically since the PMU will have all this data I’d like to output it to the original gauges and since I’ve got plenty spare on the shelf, fit some extra original gauges. The car runs the original twin tanks with an additional third tank using a modern level sender. I’ll use the PMU to calculate the overal fuel left and display it on the orignal gauge without the need for me to use the original fuel tank switch to display the level in each tank.
I’ll try using the PWM output to control it and see how it goes. The car is on the Rust2Rome social media if you’d like to see a photo.
I think oem sensor are connected to ground and will be difficult to simulate then on oem gauges as there is internal pullup there .
Could you give us a concrete example of the vaules needed for such a low pass RC filter and how to wire it?
Maybe for a one wire temperature sensor?
Thanks in advance,
Andreas