Coil pack connector replacement

[Benengo]

So my coil pack connector has melted to the top of the pack. (Golf mk4 V5)




All the pins are completely destroyed and melted. I’m guessing it’s as a result of a lose connection resulting in arcing followed by melting and shorting.

I’ve bought a new pack and a new connector. is it as simple as snipping the old connector off the loom and splicing in the new one, or is it likely to be more complex?

[stevemcs]

Its as simple as cutting off and soldering back on. Some people sell them as plugs with wires fitted on the bay of e, VW sell the connector and wires separate.

[Benengo]

The connector came with wires, so I guess I will have to get my soldering iron out!

[kambites]

I had to do this recently on our Octavia TFSI (although I had much more of a mess than you to deal with because a failed coil-pack had actually caused the plug and loom to catch fire). I just cut back the cables, put some heat-shrink wrap over them, soldered them up then slid the heat-shrink wrap up to the joint and shrunk it.

The only real issue is that the plastic casing which covers the wires and holds the plugs together had no chance of going back over the new joints; I just put zip-locks around it all and made sure nothing was touching anything hot. How long it lasts remains to be seen... looks like your engine doesn't have such a thing so it'll be easier to keep it neat.

[GreenV8S]

It's as simple as that, as long as you connect the right wire to the right terminal. A soldered splice covered with a heatshrink seal will do the job nicely. Make sure you cut back far enough to get past any heat damaged conductor - the damage may extend back further than the scorched insulation. Make sure the loom isn't tight after the repair - if necessary, insert a few inches of wire between the old loom and new connector to restore the original slack.

[Penelope Stopit]

GreenV8S said:

It's as simple as that, as long as you connect the right wire to the right terminal. A soldered splice covered with a heatshrink seal will do the job nicely. Make sure you cut back far enough to get past any heat damaged conductor - the damage may extend back further than the scorched insulation. Make sure the loom isn't tight after the repair - if necessary, insert a few inches of wire between the old loom and new connector to restore the original slack.

As above

Extend length of cables if needed

Don't have soldered heat-shrink sleeved joints side by side, stagger the soldered joints even if only 5mm clearance is achievable, 20 to 30mm is better

[Benengo]

So with the original connector disconnected from the coil pack in the state it was in, the car was starting but obviously running on 4 out of 5 cylinders.after I've now snipped it off the car now wont fire at all. I've tried connecting the replacement using chocky blocks (before repairing properly) and it wont fire (turns over happily).

It's showing fault codes for the misfire (p0305), ignition coil circuit malfunction (P0355), Throttle Actuator ctrl motor circuit range/ performance (P2101) and Ignition/dist engine speed CKT range/perf. any thoughts?

[GreenV8S]

Check you reconnected each wire to the same terminal as before.

[Dogwatch]

Penelope Stopit said:

Don't have soldered heat-shrink sleeved joints side by side, stagger the soldered joints even if only 5mm clearance is achievable, 20 to 30mm is better

My thought too before I got to your post. Neater and no chance of a short.

[Benengo]

It’s defo wired up correctly, as I kept the old connector with the ends of the wire attached. Is there anyway I could have messed up the controller logic?

Out of interest, what’s the best (easiest with limited tooling!) way to test for a spark?

[GreenV8S]

Benengo said:

Out of interest, what’s the best (easiest with limited tooling!) way to test for a spark?

Get a really cheap crappy passive strobe lamp and connect it in series with the HT lead. You can also get little adapters designed to go between the plug and its plug lead which do the same thing, but I find a timing strobe works better because you can position it in your line of sight.

Also worth confirming that you have steady ignition switched 12V on one side of the coil LT circuit and connect a small (5W or so) test lamp between that and the other LT terminal of the coil - the ECU should be pulling this low briefly each time it tries to spark.