Hello,
I am in need of some advice and help.
My 99 4.0 s-type suffers from some electrical issues that I cant get around. Please advise me what could be the problm and solutions

Battery is 1 year old Exide EA1000 900cca 100Ah, discharged several times in the past couple of months, but had it tested and all i was told it needs recharging, it charges up fully but then it can drain below 11V during 1 night due to the parasitic drain(details below)

Firstly the left front indicator gave up, replaced bulb holder and headlight wiring but no success, had to wire the bulb holder negative wire to the general electronic control module (GEM/GECM), now the indicator works and flashes with right speed but the indicator fault massage is still present and when i indicate to the left it blinks faster inside the cabin.

My other issue is an unknown sourced parasitic drain. I connected my Amp meter inline with the battery to measure the drain and after 55mins (car locked and all doors shut) the drain drops down to 0.68A, pulled all the fuses no change, however in the cold morning ( car was not used prior the test) 3 of the SWITCHED SYSTEM POWER RELAYS were warm, pulled each of them and it caused the amp reading to drop by 0.2-0.3A.

What could cause the indicator fault message, parasitic drain and how to solve them?

 

Keep tracing. Refer to the workshop manual (free download) and the many threads about this, plus the TSB they point out.

Your added wiring may well be the cause or the fault it is meant to fix.

If need be, use an auto electrician.

 

JagV8 thanks for the reply, the battery drain occurred before the temporary fix of the indicator. I recently started to think about a GEM failure, it happened before the indicator fix that the indicator was not working and I did not even get a fault message. It all happened from day 1 to day 2. I give 1 or 2 weeks to try to eliminate the problem then will take it to auto electrician. Luckily I have access to 2nd car so have plenty of time and lack of worries of draining battery, however I'm planning to go away with the Jag soon for a long 4k trip so want to sort out the problem. Would a bad relay or few cause battery drain?

 

Some quick thoughts;

Assuming you had the trunk open for access to the battery. Did you do anything with the switch for the trunk lid during the drain test? If not, the trunk light would have been on. I think it's supposed to time out if the switch thinks the trunk is left open, but I'm not positive. This could have skewed the results.

Which relays were hot? I think they are labeled R1, R2, (wait for it...) R3, etc. Wiring diagrams here:

http://jagrepair.com/images/AutoRepa...01999.25en.pdf

I'll be away for work for a couple of days. I'll only have limited online access, but will do what I can when I get back.

 

Thank you for your answer!

The warm relays were R3 R4 R5, the trunk lights were removed and the latch was clicked into closed position, the switch was clamped. Made sure all doors (trunk and drivers) were clicked into closed position as well as the bonnet. :/ it was always fluctuating between 0.68 and 0.67A,
I much appreciate your help and JagV8s! Thank you both

 

I think you have two more fuse/relay boxes so be sure to check those too.

Even a chafed wire could be the GECM/etc cause. It may well not be the module.

Also, you could read all the codes from all the modules, clear them, and see which come back. OE-type tool.

 

From the back of a 737:

Have you tried the drain test with the alarm both on and off? I wonder if that would make a difference, might narrow down the path for troubleshooting.

 

Haha I love flying and aeroplanes (aircraft engineering student here)
Have a great holiday!
I actually took out the radio and explored 3 scotch locks! So someone prior my ownership already touched that area, right now when I write this message I'm 10 mins into a drain test, hoping to see some low numbers, after mins it dropped down to 0.79A when it used be around 1.12A

 

Also, when I disconnected the fuses cartridges for the corresponding relays it drops by 0.6A!

 

Regarding your indicator fault message you should consider changing out the turn signal stalk assembly.

I had a similar issue a few years back on my 00 S Type and it turned out the stalk internals were worn out...

+1 you should reverse your additional wiring before you take your GEM out...

 

Will try to swap over with another unit, tbf when I turn the steering wheel sometimes I do notice but never could make sure that the blinking noise returns to correct it's like there's a delay in the fast clicking, also sometimes makes an absolutely different beep!
The additional wiring is the only reason I have indicator now, it's basically a negative line wired straight from bulb do GEM's corresponding pin (S-Type electrical guide became my bible) thank you for your answer, I appreciate it, goodrove idea to see if a new stalk assembly works!

 

Check for water ingress into the boot. Reverse aid module. And other wiring. I had a car with excessive drain. Was keeping drivers seat module awake. Traced to water in boot which had travelled UP the loom in the boot and was waking things up. I don't know how but I know it did.

 

Be very suspicious of anything after market installed.

You mention scotch locks and a radio. Be sure and take all that out of the circuit when chasing the electrical drain.
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I had water ingress like 2 years ago, since then tail lights were sealed up, no water can get it, however made me very suspicious that one or 2 of my relays are stuck closed!

 

A day late and a dollar short here, but can you please confirm something about the relay identification? Here's an excerpt from the wiring diagram:







Note how the large square relays are labeled #1 - #5 on the relays themselves. However, the nomenclature at the bottom doesn't quite jibe for all of them.


Relay #1 = Switched System Power Relay 1


Relay #2 = Switched System Power Relay 2


Relay #3 = Heated Backlight Relay


Relay #4 = Switched System Power Relay 3 (confusing)


Relay #5 = Switched System Power Relay 4 (confusing)




So before digging too deeply into the diagrams, I just wanted to be sure which relays were staying warm.

 

Thank you for your reply and sorry for my delayed one, for my excuse im on my 6 th night shift and I'm knackered.

Looking at the diagram you attached the relays are in this order of temp: #4 #5 #2 #1
Nr4 being warmest and nr1 least:/ i am quite inclide towards a faulty GECM.

Yesterday on the way to work i got left SIDE indicator fault message then it disappeared and all was fine (while message was on the indicator was still working fine) before i added the additional wire from FRONT indicator to GECM it happened couple of times that the indicator was not working and I had NO fault message or fast dash feedback blinking either

Am i right assuming my GECM is faulty??

 

I'm perplexed by this extra wire you added. If it was installed correctly and replaced a broken wire, it shouldn't make any difference. Was the damaged section cut out completely? Or is the original wire still connected at both ends, and the new wire is spliced in parallel? If the original is still connected, you could have a bare spot rubbing against ground or another wire. Then all bets are off.


Back to the four "switched system power relays". Look at wiring diagram figure 01.5. (Link to wiring diagrams in post #4). All four relays are energized at the same time. Each has a separate power supply, and then the four grounds are joined in parallel. Either the General Electronic Control Module or the Rear Electronic Control Module can supply the ground needed to energize all four relays.


I'd suggest unplugging either one of the modules and repeating the parasitic drain test. If still bad, reconnect that module, disconnect the other, and repeat the test. This should tell you which module is commanding those four relays to stay energized.


The BIG question after that is determining why the module is giving the command. Is it due to a faulty module? Or is it a bad input to the module, and module is behaving exactly as designed? This could be really tricky to diagnose without some means to read the SCP bus and see what is and isn't active after everything should have entered sleep mode.


Please see this note at the upper left corner of fig 1.5:


"SCP NOTE: The switched system power relays are activated by


the GECM or the RECM whenever messages are present on the


SCP Network. After the ignition is switched off, the relays remain


activated until all SCP messages are removed."




Without some means to read the SCP bus, you might be able to find a bad input by unplugging other connecting modules one at a time and repeating the drain test. For example, see the previous comment in this thread about a driver's door module that remained active.

 

thank you for the great and we'll detailed answer! I will put my battery on charger tomorrow morning (I'm in work at the moment) and charge it 24h so the battery will be 100% fine and charged. Then I will follow your advised steps. Will get back to you as soon as I finished with testing the Control Modules.

regarding the added wire, I did not cut the old wire as I'm afraid to do so, it's a main wiring that connects into the GECM and in afraid what if the problem lies somewhere else.

Car used to keep charge fine for several weeks than since I bought another daily and didn't use her for several weeks it started to play up.

thank you very very much for your help, I really appreciate it