Continuing my investigations into the reasons for a quiescent drain problem my S type is experiencing I found some wiring issues with the adaptive damping control module and I have taken a picture to accompany this thread.

I would like to eliminate the DSC controle module as a source for the quiescent drain of 2.4 amps this car has been routinely experiencing. Is it the left side connector [as shown in the picture] or is it the right side that goes to the DSC module?

I plan to undo the connections shown on the left side connector and use solder to replace the quick connectors currently in place but I don't know if this will affect the battery drain yet.

The wire that runs to the centre of the ADC module looks buckshee. Is this a normal setup or is it buckshee as well.

Bob

 

I'd refer to the workshop manual and its elec guide.

 

You are right about the connector question of course and I can determine that from my schematic but I did want to hear about the black and white wire that runs from the connector to the middle of the module. Is this the norm, i.e., to be found on all other adaptive damping modules of a similar age? Just a little concerned that somebody has wired in something that doesn't need to be there.

 

I have a different car but maybe someone will say.

 

Be careful not to power up the system with the module disconnected. You'll get a fault notification on the dash. C prefix codes (which are part of the adaptive suspension) can't be erased with normal DIY scanners. I mistakenly powered on the system while working on it, got the codes, and had to have them erased by a shop using Auto Enginuity. Cost me $80.

Additionally, if any part of the CATS system, not just the module, is disconnected and the car is powered on, codes will be set.

 

Might be too late for me Jim. I checked the system with the grey connector disconnected yesterday and the 2.6 amp drain disappeared. I will not run it with the blue connector disconnected because of your caution however. The grey connector [CA12] runs four wires to the three accelerometers, one of which I disconnected yesterday. I was planning to disconnect the one located in the trunk today.

I had a look at the black/white wire that runs to the centre of the module and discovered that the red/yellow B+ wire is snipped off at the connector and connected to this black/white wire which in turn seems to be soldered at a point near the middle of the module [see picture]. Disturbing because this shows a level of understanding of the module that exceeds my own.

 

Okay, I have now disconnected all of the accelerometers one by one and none of these disconnections has resulted in a drop in the drain of 2.4 amps. That casts all of my suspicion back onto the ADC module as the source of the drain.

The yellow/red wire to the ADCM was cut and a wire was run to the approximate centre of the module. This is now my prime suspect. I might try to rejoin the original wire to the connector and see what that brings.

Perhaps there is a corrosion problem with the module that the rewiring was trying to correct. I will have a good look at the module when I have it out and see what I can see in terms of obvious corrosion.

Perhaps I can then take a picture of the module and see what the Jag experts think.

 

Just to finish this long running story, I bought a used ADC module from the U.K. and my quiescent battery drain stopped. I should have been listening to the car because it kept warning me about the adaptive damping system but I ignored the warnings. Regardless, I now have this particular bit of sleuthing behind me.

I think it was the rewiring job that had been done on the ADCM that was the source of my problem. The module had either experienced moisture from some source or it had been in a damp environment for the last sixteen years. The pins on the module are green in places and one of them is missing. Perhaps the pin broke when an earlier owner or mechanic tried to separate the connector [the female connector looks a bit banged up]. His solution was to wire around the break which was probably not such a bad idea.

But he also joined together the B+ wires using a horseshoe connector and this shorted together the switched B+ and the unswitched B+. This could have quite easily led to the drain. Probably the module is okay except for its missing pin. If I get ambitious I might try to replace the pin and give the old module a try.

It has been an interesting challenge. Thanks to all who helped me along the way in the forum.

I am a pretty happy camper for the moment.

Bob

 

What a pain!

 

Since this car is not my daily driver [an old Volvo fills this role] I have enjoyed the challenge and have found out some interesting things about this rather lovely car. I do admit however that it would have been a great pain in the butt, not to mention the pocketbook, if I had been relying on it for transportation. It made my day to find the source of the drain on my own.

Bob