Ignition Coil - Whats Positve And Whats Negative?

[chocolate_o_brian 0]

As above really. Bought me a new coil from Partco (Scunnies answer to Motor Factors) and it has the two screw things for the leads and is labelled positive/negative.

 

But the coil on there now isn't labelled (see below)

 

Can someone tell me which side on the above coil is positive and which is negative please, so I don't blow me and my neighbours up The only markings are a number "1" on both sides and a number "4" at the top (which you can just about make out).

 

TIA

 

Andy

Edited June 8, 2009 by chocolate_o_brian

[Rom 0]

Without testing, with a multimeter, i could only hazard a guess... But id say the side with blue connectors is the postivie.

 

Based purely on the fact its the thicker wire, and is red.

[MrG 3]

I've just done this and on mine the + is to the right the word Bosch with the number 4 above it (word Bosch is at the bottom, the circular indent/mark is at the top for orientation)

[DamirGTI 325]

Except +- markings on the coils are usually numerical 1 and 15 = 1 being negative and 15 positive terminal

 

I have the same Bosch coil as the one on the pic and these ones are marked with +- as well as the numbers 1 15 (clean up the area around the terminals and you'll see the +- marks !)

 

Damir

[wracing 19]

i don't want to be controversial but it doesn't really matter that much which way round you connect them as long as the pairs stay together. in the picture the connections closest to the bulk head are negative and the one closest to the engine as positive. a multimeter will tell you nothing as there is no arrester diode in these coils.

 

james

[MrG 3]

ah interesting, I didn't know that regards the group or the numbers, mine has both numbers and + - marks.

[Guest Craig.P]

I've just done this and on mine the + is to the right the word Bosch with the number 4 above it (word Bosch is at the bottom, the circular indent/mark is at the top for orientation)

 

Andy,

 

This looks very similar to mine, I inherited a half stripped 205 and had to trace the wires for the coil, brown and red wires with blue terminals will probably be the switched positive (+ve), one will probably come from the main loom running accross the front of the block, the other will be a piggy-backed positive feed to the ignition module. On the other side of the coil (-ve) the large green sleeved wire is the ignition pulse signal to the ECU / tachymetric relay, I suspect the small grey is the rev counter signal and the violet is the pulse signal from the ignition module (you should be able to trace the ignition module wiring). If needed I'll take a photo of the coil set up on mine if you need it.

 

Craig. P

[chocolate_o_brian 0]

Thanks for your replies guys. Car electrics are my worst nightmare, and I was at a mates today (Flix) attempting this. But we didn't know which way to do it regards +ive -ive or just pairing the same.

 

I will try the cleaning up and see what that yields.

 

Craig, if you wanna take a pic, go for it mate as a lot of the wiring on my car is bodged the feck so it's quite confusing to work on.

[Guest Craig.P]

Coil connections photo link

 

 

Andy

 

(deep breath)............ The two reds on the right hand side are +ve, one is the ignition switched feed from the main loom and the other is a piggybacked +ve feed to the ignition module.

 

The group on the left hand side are:- one large sleeved green, is the ecu rpm signal, the other large green sleeved is the tachymetric relay rpm signal, grey is the rev counter signal and the large yellow is the pulse signal from the ignition module.

 

I hope this helps.

 

Craig

Edited June 8, 2009 by Craig.P

[chocolate_o_brian 0]

Coil connections photo link

 

 

Andy

 

(deep breath)............ The two reds on the right hand side are +ve, one is the ignition switched feed from the main loom and the other is a piggybacked +ve feed to the ignition module.

 

The group on the left hand side are:- one large sleeved green, is the ecu rpm signal, the other large green sleeved is the tachymetric relay rpm signal, grey is the rev counter signal and the large yellow is the pulse signal from the ignition module.

 

I hope this helps.

 

Craig

 

 

For a guy with 2 posts, you're obscenely knowledgeable

 

But many thanks for the help, can crack on later and electrocute oneself

[lagonda 41]

Probably not much wrong with your old coil....but it needs to be clean! Toothbrush & Swarfega, good rinse & dry would do the trick. All that crud at the top will encourage arcing, so less volts at plugs! Also the terminals need to be clean...wire wool ideal there. If you do fit the new coil, keep the old one as a spare...aftermarket coils won't be built to the same quality as the original (Bosch)...so you might be glad you kept it!