What is a jumper wire?

wannabemedic

Anyone know? I went to halfords to ask for one because I need to do some diagnosis on the car ecu, and it needs a 'jumper wire' to connect one terminal to another to get it into diagnostic mode.

Halfords didnt' know what I was talking about :mad: so does anyone know what other name it may have or where I can find one? They tried to sell me jump leads which are a bit big for my needs :eek: thanks

Conor_3

No such thing really exists..people make their own up or they come as part of diagnostic kits.

wannabemedic

I see how do I make my own, what kind of wire am I looking for to make one?

Wig

You take any piece of wire long enough to go between the two terminals, you stick one end in one terminal, and stick the other end into the other terminal.

It's just a bit of wire


You can use for example
a paper clip unbend it
a piece of indoor 2 core lighting wire (with a brown and blue cores) strip it out so you have a length of either the brown or blue strip 1 cm of the blue insulation from both ends, twist the copper strands to make them strong (or dab a bit flux & solder onto the ends)
Job done.

Make sure you know which termiinals EXACTLY are to be connected check twice connect once, (like cutting wood measure twice cut once)

If you want to be really posh you can put a spade connector on each end (if appropriate).

wannabemedic

Okie dokie thanks for that I've got the old plug & lead i cut off from an old tv before scrapping it so I'll cut some off the end and do that, i wasn't sure about how thick/thin the wire should be! The manual makes it clear which slots to use but what could happen if it's wrong? would the car just stop working or something

bartman

wannabemedic wrote: »

what could happen if it's wrong? would the car just stop working or something

There is every possibility that you could fry the ECU altogether! Make very sure that you know which terminals you are going to bridge; ECUs are not cheap to replace!

Good luck!

Wig

If it's wrong, you could ruin the ECU, but if the Haynes manual (or whatever) shows you clearly which ones, just make sure you have got it absolutely correct before joining them
. You can buy spade connectors from auto shops and possibly B&Q or other DIY shop and Maplin, and Halfords. I'm sure they will give you about 5 for £1.99 :mad:

Just get the same size ones as the connectors which fit into the slots, as it's ECU work you would be well advised to get some spade connectors, to make sure you get a good and permanent fit.

wannabemedic

this is £1.29 at maplin - just being my stupid self here but how does a spade connector help over a wire end as long as I make sure its in properly? i'm also not sure what size the ecu slot is

cyclonebri1

Agree totally with all thats been said, but don't attempt it unless you know what you are doing. You will also need to know how to interpret the message given as it is often a series of morse code flashes using the engine management light on the dash.
If its a popular car try the owners club forum, that sort of stuff usually gets "stickied";)

cyclonebri1

wannabemedic wrote: »

this is £1.29 at maplin - just being my stupid self here but how does a spade connector help over a wire end as long as I make sure its in properly? i'm also not sure what size the ecu slot is

Like I just said, I get the impression you'd be better with a little help, no offence, and yes provided you have space that mini type spade connector or possibly the male version would do. Do you know where the diagnostic socket is? Have a look it'll give you an idea of what will work, again becareful:rolleyes:

wannabemedic

I know where it all is and what to do but not sure i should do this on my own as i've not done anything of the sort before now you mention it! i'll ask the garage i go to (not the dealer lol) to do it for me, more peace of mind and i think they have better equipment too