Electrical gremlins

gazcon · 17th August 2018, 10:59

Hi,

The story so far...

-Car running fine (2.5v6 auto 1999 build).

-Wiper motor making a racket.

-Replaced wiper mechanism and motor with one from eBay

-Car now completely dead.

To swap the wiper mechanism over I....

- Removed all scuttle panel clips
- Removed wiper arms
- Removed scuttle panel
- Unbolted 3 bolts holding the wiper mechanism in, swapped for the new one

The only wiring that has been disturbed is the wiring to the wiper motor and what looks to me to be a rather strange earth wire which earths to the bonnet using the bolt on the passenger side bonnet strut. There's an earth lead from the ECU to a point just to the right of the ECU, and then this rather strange lead runs from there up to the bonnet.

I say "rather strange" as it was cable tied to the bonnet strut, is a flat weave cable, and on removing the plastic shrouding to check for any breaks found some insulation tape wrapped half way along it (although no breaks in it when I removed that), and I don't have this cable at all on my facelift 75.

I'm suspecting this earth cable is somehow the root of the problem as it had to be gently maneuvered out of the way to remove the scuttle panel and I haven't touched anything else.

I have charged the battery overnight, and tried a known good battery with no joy, so we can rule that out.

When I turn the ignition on weird elctrical things happen. The dash lights don't look right and if I try to start it nothing happens and you get the flashing headlights like the battery is dead. Sometimes weird things happen like the CD changer in the glovebox will start whirring and clicking.

https://youtu.be/rwjxImfN2eM

Having removed that earth cable, checked for any breaks, cleaned up the contacts and refitted it the problem is worse. Now I just switch to position one on the ignition and the bit where the mileage is displayed flashes on and off, there are clicking noises, and a "plipping" noise like the alarm sounder. I then switch off very quickly indeed.

I'm totally at a loss.

Can anyone tell me if this weird looking earth cable earthing at the bonnet strut is standard or if it's something a previous owner has added?

Is it time to call in the services of MarinaBrian or some other guru and get the ECU looked at?

Can't believe such a simple job has goosed the car

gazcon · 17th August 2018, 17:37

Just to add I've had a good look around the ECU and can't seen any obvious issues - the earth is securely connected, there's no tide mark on the ECU casing or on the pollen filter when I changed that a few weeks ago. Plenums bone dry.

It's really weird. Although I removed the scuttle panel I'm fairly sure I left the panel that sits on top of the ECU and pollen filter in place. I really don't see how any wiring could have been damaged, other than possibly the bonnet earth (which looking on eBay I see is a genuine item) and I've stripped the insulation off that to check for breaks and it's fine.

I've even removed the wiper mechanism I fitted so I could have a good look around and make sure I hadn't pinched any wires, it all looks as it should. But still behaving strangely with the ignition on and won't start.

kelvo · 17th August 2018, 17:43

The earth cable from the bonnet to the scuttle panel was fitted to early cars but removed as part of project drive I believe. You don't actually need it anyway.

From what you have described it sounds like an earthing problem of some sort, first thing I would try is put the old wiper motor back and see what happens.

The symptoms you describe do also sound exactly like a dud battery, have you got another battery to try - could just be coincidence?

Can you put a meter across the battery and operate the starter and see what the voltage drops down to, when I had a battery fail with those symptoms it went down to about 9 volts and was stone dead.

*sorry just read you've tried another battery so can rule that out*

gazcon · 19th August 2018, 10:08

Any further thoughts from any electrical gurus out there? Completely stumped.

suffolk boy · 19th August 2018, 10:25

these cars have habit of things failing at the same time as you did something else.leading you up the garden path.check the battery earth clean the connection to the body .get a meter and see it if you getting power to the starter motor. remove the ecu and check the connections you may have disturbed these when you did the filter.do one thing at a time and use a process of elimination.good luck

Mike Noc · 19th August 2018, 10:45

Check the main earth cables from the engine to the body, and the battery negative to the body, and remove and clean the cable end connections.

.

17th August 2018, 10:59	#1
gazcon Avid contributor Rover 75 2004 Cdti Contemporary & a 1999 V6 "jap spec" Join Date: Sep 2010 Location: Norfolk Posts: 226 Thanks: 111 Thanked 28 Times in 24 Posts	Electrical gremlins Hi, The story so far... -Car running fine (2.5v6 auto 1999 build). -Wiper motor making a racket. -Replaced wiper mechanism and motor with one from eBay -Car now completely dead. To swap the wiper mechanism over I.... - Removed all scuttle panel clips - Removed wiper arms - Removed scuttle panel - Unbolted 3 bolts holding the wiper mechanism in, swapped for the new one The only wiring that has been disturbed is the wiring to the wiper motor and what looks to me to be a rather strange earth wire which earths to the bonnet using the bolt on the passenger side bonnet strut. There's an earth lead from the ECU to a point just to the right of the ECU, and then this rather strange lead runs from there up to the bonnet. I say "rather strange" as it was cable tied to the bonnet strut, is a flat weave cable, and on removing the plastic shrouding to check for any breaks found some insulation tape wrapped half way along it (although no breaks in it when I removed that), and I don't have this cable at all on my facelift 75. I'm suspecting this earth cable is somehow the root of the problem as it had to be gently maneuvered out of the way to remove the scuttle panel and I haven't touched anything else. I have charged the battery overnight, and tried a known good battery with no joy, so we can rule that out. When I turn the ignition on weird elctrical things happen. The dash lights don't look right and if I try to start it nothing happens and you get the flashing headlights like the battery is dead. Sometimes weird things happen like the CD changer in the glovebox will start whirring and clicking. https://youtu.be/rwjxImfN2eM Having removed that earth cable, checked for any breaks, cleaned up the contacts and refitted it the problem is worse. Now I just switch to position one on the ignition and the bit where the mileage is displayed flashes on and off, there are clicking noises, and a "plipping" noise like the alarm sounder. I then switch off very quickly indeed. I'm totally at a loss. Can anyone tell me if this weird looking earth cable earthing at the bonnet strut is standard or if it's something a previous owner has added? Is it time to call in the services of MarinaBrian or some other guru and get the ECU looked at? Can't believe such a simple job has goosed the car Last edited by gazcon; 17th August 2018 at 11:19..

17th August 2018, 17:43	#3
kelvo Gets stuck in MG ZT 190 SE Join Date: Oct 2017 Location: Chatham, Kent Posts: 569 Thanks: 22 Thanked 163 Times in 135 Posts	The earth cable from the bonnet to the scuttle panel was fitted to early cars but removed as part of project drive I believe. You don't actually need it anyway. From what you have described it sounds like an earthing problem of some sort, first thing I would try is put the old wiper motor back and see what happens. The symptoms you describe do also sound exactly like a dud battery, have you got another battery to try - could just be coincidence? Can you put a meter across the battery and operate the starter and see what the voltage drops down to, when I had a battery fail with those symptoms it went down to about 9 volts and was stone dead. sorry just read you've tried another battery so can rule that out Last edited by kelvo; 17th August 2018 at 17:46.. Reason: did read post properly.

19th August 2018, 10:25	#5
suffolk boy This is my second home fiat panda Join Date: Sep 2009 Location: haverhill Posts: 6,720 Thanks: 96 Thanked 586 Times in 526 Posts	these cars have habit of things failing at the same time as you did something else.leading you up the garden path.check the battery earth clean the connection to the body .get a meter and see it if you getting power to the starter motor. remove the ecu and check the connections you may have disturbed these when you did the filter.do one thing at a time and use a process of elimination.good luck __________________ fiat panda 1.2 eco

19th August 2018, 10:45	#6
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,547 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Check the main earth cables from the engine to the body, and the battery negative to the body, and remove and clean the cable end connections. . Last edited by Mike Noc; 19th August 2018 at 19:51..

17th August 2018, 17:37	#2
gazcon Avid contributor Rover 75 2004 Cdti Contemporary & a 1999 V6 "jap spec" Join Date: Sep 2010 Location: Norfolk Posts: 226 Thanks: 111 Thanked 28 Times in 24 Posts	Just to add I've had a good look around the ECU and can't seen any obvious issues - the earth is securely connected, there's no tide mark on the ECU casing or on the pollen filter when I changed that a few weeks ago. Plenums bone dry. It's really weird. Although I removed the scuttle panel I'm fairly sure I left the panel that sits on top of the ECU and pollen filter in place. I really don't see how any wiring could have been damaged, other than possibly the bonnet earth (which looking on eBay I see is a genuine item) and I've stripped the insulation off that to check for breaks and it's fine. I've even removed the wiper mechanism I fitted so I could have a good look around and make sure I hadn't pinched any wires, it all looks as it should. But still behaving strangely with the ignition on and won't start.

19th August 2018, 10:08	#4
gazcon Avid contributor Rover 75 2004 Cdti Contemporary & a 1999 V6 "jap spec" Join Date: Sep 2010 Location: Norfolk Posts: 226 Thanks: 111 Thanked 28 Times in 24 Posts	Any further thoughts from any electrical gurus out there? Completely stumped.