Thread: LPG Conversion kit for 79 RR

Originally posted by LandyAndy
Hi guys
You need an LPG specific gauge to read LPG,cant recall exactly the ratings,but the petrol and gas senders run on completely different ohms.If needed I can check tommorow wich the LPG is(1 is like 90 ohms and the other 180 ohms,but thats a guess) as I have a near new LPG VDO gauge in my 109,a working petrol gauge wouldnt work correctly on LPG.The switches that make the dash gauge read LPG have a built in conversion factor.A petrol gauge wont read correct on a LPG tank and vice versa.
Andrew

Yep, you're right.
A check of the VDO website confirms this.

I have twin gas tanks, so the signals are probably summed to form 180ohms.
Can't tell. Both gauges (petrol & gas) look identical.

But definately worth considering if installing from scratch.

There is a calibrater available to change the output to the correct ohms, but if you work out what the dash gauge range is in ohms , a simple resistor or 2 will fix that. With twin lpg tanks, set the gauge to read off the tank furthest away from the T piece. In my other Rangie, the lpg gauge was one of those led ones that fits under the dash but i kept bashing it with my knee.