Hi all! My name is Matt.

First of all, forgive me if this is in the wrong section. I tried to put it where I thought was best. Secondly I know nothing about cars. I'm in a bit of a bind and thought I'd see if I could get some friendly insight/advice before I use up my roadside assist or money on more practical solutions.

My problem revolves around two Mitsubishi Magnas. Both dual fuel, both late 90s. The cars were both recently fitted with new batteries from K-Mart. My dad's stopped working straight away. Would try to turn over, but couldn't get there. Mine turned over after a few seconds, but the switch to change from petrol to LPG was completely non-functioning. No lights, no nothing. I went to start it earlier this evening and now it won't even start. Same problem as my dad's car - it tries to turn over but can't seem to do it. My dad changed the batteries over, but he's done it hundreds of times before without incident. I would think he knew what he was doing with a simple battery change. It fits the battery compartment fine and everything. Nothing seems wrong visually, and yet...

My dad had the RACV round for his car a couple of nights ago. They couldn't figure the problem out. The LPG fuse was getting charge from the input end, but nothing from the other end, and every time they tried to replace it, it would blow. But they couldn't offer a solution.

So, before I get it towed to an auto-electrician and use up my roadside assist, does anybody here have any insight for me?

Thank you so much for any help you can offer. It's greatly appreciated!

Most LPG installs have either a connector on the positive side of the battery or one on both terminals of the battery. Have both of these been reconnected when the batteries were changed???

Yep. Everything has been put back where it was. My dad's car only had one going to the positive. Apparently (my dad did the install so I'll have to trust him for now), mine had two but both to the negative. Neither were long enough to reach the positive. When I get the chance I will double check this.

Thanks for the response.

My apologies - just checked the battery myself and there's one lead going to positive and one to negative on mine. My dad has just the one to positive. Mine has a 7.5 fuse, my dad's has a 10 fuse. Don't know whether mine is blown but my dad's is.

welcome to the club mate . check all fuse,s under dash and under the bonnet
plus where in vic are you

Maybe you are getting too much fuel? Depending on the system used, the car may well start on petrol and then switch to gas after a few seconds. This is to give the gas some time to come through to the converter. If you already have enough gas there, the mixture will be too rich and it will not start. Try taking the fuse out from the gas supply and crank it over. If it starts OK, this is the answer. You may then have to alter the delay when the LPG Cuts in. You may have to crank the engine over for a while - maybe 30 seconds to clear the rich mixture from the engine.