start up dependent on drivers seat position...

[cadlington]

Hi there, I have found an interesting fault with my new van. When the drivers seat is all the way back it appears to short the battery and the engine won't start. When I move the seat forward, the issue disappears. Has anyone experienced this before?

[scottbott]

is it a westy?,sounds like battery cover(metal?) shorting out

[cadlington]

It isn't a westy, it's a diy conversion with leisure battery, inverter, hook up etc.

I had a look at the battery cover but it looked and felt like plastic which is why I found it weird!

I don't know enough about how the extra electrics are wired up but could it be they are affecting it somehow?

[marlinowner]

Left or right hand drive?
It ses unlikely to be anything other than the seat base touching the battery terminal or connector.

[Smcknighty]

Appears to short or you hear it arcing? 12v short on the battery can cause a fire so I'd suggest if it's arcing you need to get it sorted pronto. Presumably the battery is in the box under the seat? If you can't hear the crackle it's possible the seat is knocking or moving a cable?

The problem with these electrics people cobble together is that they do crazy stuff. Example in my van some crazy ex owner had decided it was ok to solder wires (with exposed bare bits!) into the 240v supply line and use that to run something else. Then when finished with that they figured they could just cut it and leave the cable loose down the side of the rear seat.

To me that's insanely dangerous, to them it was no biggie, they knew not to stick their fingers down there..

If your not sure about the wiring can probably post photos and diagram on here for advice. Or get an auto electrician to look at it (or competent friend)

[cadlington]

Cheers for the replies. It is a RHD with the battery located under the seat where it should be.

My original thoughts were that it was being shorted somehow, and will definitely be looking into it tonight to check it isn't a fire risk. Since Smcknighty mentioned a cable being moved, this sounds more likely to me!

I'll have a search for a wiring diagram in the big box of paperwork that came with the van, failing that I'll have to draw one up myself so I know what is going on. I have a feeling that the leisure battery is dead so when I replace it I'll document how it's all wired up.

[Ralf85]

Sounds like you have no insulation between the positive pole on your battery and the lid above it. Or somebody may have fitted an oversized battery under the seat. I have supplemented the insulation on my lid with one of the plastic covers that are fitted over the battery poles when bought new.

[cadlington]

Hi guys, just wanted to say thanks for your help on the matter. I have temporarily resolved the issue hopefully...

There was a piece of insulation over the positive pole, but not over the negative pole. I've have now placed insulation over both poles and it works!

But this does lead me to believe I have an earthing issue somewhere?

[CovKid]

Clean the battery terminals well and make sure clamps are on firmly.

[AdrianC]

I have temporarily resolved the issue hopefully...

There was a piece of insulation over the positive pole, but not over the negative pole. I've have now placed insulation over both poles and it works!

But this does lead me to believe I have an earthing issue somewhere?

The battery -ve terminal is meant to be in excellent electrical contact with every single bit of metal bodywork in the van - that's what the earth is... And that means that if you were shorting from the battery flap to +ve terminal, you'd KNOW about it. Flash, bang, smoke, scorch marks, melted battery terminals.

So - it's gotta be a poor connection somewhere. A cracked terminal is a good starting point to look at, but a poor connection somewhere in there is not unlikely. You can find it now, or you can wait until it fails completely and it'll be easier to find... but if it leaves you with a stray +ve lead...

[ghost123uk]

Just popped in to backup and expand on what Adrian just said above. Please take care here. A shorted battery +ve can cause fire, yes, but it can also cause your battery (which contains Sulphuric Acid) to explode in a big way. I have seen this once, thankfully from a distance. A GPO mechanic shorted out the battery on a GPO van with a socket bar. It welded itself to the terminals, there was a lot of smoke then a huge bang and the guy and the inside of the van got covered in HOT Sulphuric Acid. He was doused in water but still had to go to hospital. He was not blinded, or disfigured in this instance, but only by the grace of god (other deities are available).

Take care.