75ZT Community

Finally we have found the source of the electrical problems on the 'S' reg car.
The multi-way connector in the A pillar of the driver's side has had water ingress and is in a bad way, with a couple of pins rotted away.

Pictures taken with my phone so aren't brilliant.







It's amazing how this has manifested itself eg. problems with the heater and Hi-line unit.

I think the best solution is to splice in a complete connector from a donor car. It shouldn't take more than a couple of hours to do even though there isn't much room to work in the A pillar side.

Oh well, down to the scrapyard again I guess.

Water always seems to find a way in, and the worse part is it always causes random unrelated problems

If you want to change individual contacts I have dozens of them Bernard.

raistlin wrote:If you want to change individual contacts I have dozens of them Bernard.

Wow, that would be easier but doesn't it need an extractor tool to get them out?

Bernard wrote:

raistlin wrote:If you want to change individual contacts I have dozens of them Bernard.

Wow, that would be easier but doesn't it need an extractor tool to get them out?

No, you just need to open the latch on the connector body (if there is one) and then use a probe to push the spring contact down Bernard.

You can see the spring contacts in the first of your pictures above.

Technically you are supposed to have a specific crimping tool but either:-

1. You can crimp them with pliers if you're careful (not recommended)

2. You can borrow the precise crimping tool from me (recommended)

raistlin wrote:No, you just need to open the latch on the connector body and then use a probe to push the spring contact down Bernard.

Ah, I see! Will have a look to see how many are tatered, when I've got a few minutes that is.

Have you got the M & F pins? There's verdigris on several both sides.
I've got several crimp tools so I guess one of them will do the job, if not perfectly.

At least we now know the problem, the previous owner gave up with it, I believe.

This is a good company for connectors, pins etc and also tools including pin removal tools

http://www.vehicle-wiring-products.eu/V ... mepage.php

Yes, I have both pins and sockets Bernard.

HI Bernard
Just incase would it be any good to get these connectors from the MG ZT 1.8t i am going to send off tomorrow before shes gos let me know also wher i can find them cheers Arctic

I think that we have this sorted now thanks.
We have a donor car from a friend who wants rid of it.

JDCs car was very similar, though it didn't have such severe symptoms.

Good news is that the problems went away after replacing the connector and part looms.

Bad news is that it now comes back but only after 20 minutes running.

There's still damp in something somewhere. Remind me of the thread with the problem description if you would.

This one, Duncan -

bcu-problem-t3905.html#p35697

Hi Bernard. Very similar to my problem I think, just in a different place. I'm guessing the door looms go to the BCU (Body Control Unit). Might be worth checking the state of the connections there, as looking at the amount of damage to the original door jam plug, the water could be a lot further into the loom, as it was in mine. Solution for me was to replace the engine loom.

We have managed a few more hours on this problem this week. Again I thought we had found it when the fault could be certainly switched on and off by moving the loom at the connector end to the offside connector of the instrument cluster. Aha! Indicates a poor connection here or a dry joint on the connector to pcb pads, I convinced myself .

Connectors all looked good so stripped the cluster down and re-flowed the relevant joints. Then spent 1/2 hour looking for one of the instrument needles.
Fault does not come and go with the movement any more but is back to the 10-15 minute running OK syndrome. At this point the breaker's yard is looking more attractive but I don't really want to give up, I've spent too long on it and don't like to be beaten.

What I cannot get my head around is how we could provoke the fault for a short time by moving the loom at four different places so far in turn but only until we investigate that point whereupon the fault goes back into its cycle of being OK for several minutes and cannot be provoked again during that time.

I think that I now need to eliminate the cluster so as not to get bogged down by it plus I don't know what else to try. What are the implications of trying a cluster from another vehicle for the purposes of elimination?

As far as I know, another cluster won't cause any problems, but you will get an error in the trip area.

It might be worth getting a meter. or better still a scope, on kbus to see what the voltages are doing when it's OK and faulty.

When working properly it should switch rapidy (9600 baud) between Vbat and ground less a few mV. If it changes significantly as the fault comes and goes, then something is affecting the bus. That could be a wire running over a sharp edge, or still water in something (though I'm struggling to suggest what)

Thanks Duncan, I've got to try and find my 'scope, left it somewhere.
I thought we were on to something when we found that the immobiliser was damp but all the connectors etc. have been dried and are OK. The looms, as far as can be seen, are well wrapped and tethered at any critical point, there is not much left now to investigate.