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Discussion Starter · #1 · (Edited)
Classic no crank, no start with a single click heard. I've read all the threads on this and I will be taking off the plenum(s) to check on the battery cable in the valley of the engine - and checking power to the starter and starter solenoid. But, here are some interesting things that may or may not be related.

1. Here is a picture of the battery. there is a plug with a blue and red wire that is just sitting there. Does anyone know what this is for?
Electronics Technology Auto part Vehicle Electronic device

2. Used ISTA/D (Rheingold) to check on the various buses and modules, and see fault errors. I did this twice

2.1 The first time RLS, ACSN/MRS; and CON showed red i.e. not communicating. CAS, IHKA, and SINE show faults. The CAS error is "Terminal 50 at CAS"

2.2 The second time it was RLS, ACSM/MRS; AMP_0x37; and CID that showed red. the same 3 modules with faults. The CAS fault was A0C1 CAS: Output, terminal 50. I also have 9D12 SINE: Internal Battery; and E71D Auxiliary water pump message error.

2.3 There were other module issues but they got truncated on the printout which I didn't see until I had put everything away. (Not to sell - print landscape in ISTA).

I may have 2.1 and 2.2 reversed - but the point is that things changed from one test to the next without clearing anything. To my E60-novice brain, this seems like some kind of power issue.

I checked power at the battery - strong over 12 volts. The same thing at the main terminal in the engine, and at the terminal near the LHS hookup near the plenum.



What I plan to do is take out everything as if I'm going to change the starter and test the 3rd terminal in the valley and then check the starter and its solenoid. I have a replacement in my parts cupboard if I need it.

Given how the modules showing as RED in ISTA changed one test to the next, I suspect something electronic - and I'm a little out of my depth here, but it sure seems like power isn't getting where its needed as opposed to a mechanical failure.

Does anyone have any other suggestions or things to try - possible relays, fuses, etc that I should check? I could really use your input and advice. Thanks.
 

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Discussion Starter · #3 · (Edited)
Thanks for the response. Been there done that. I'm looking for those possibly deeply hidden gems of wisdom of places to look for if checking the 3 +tive terminals and the ground (plus at the starter) doesn't resolve the issue. Where has anyone gone next?

I'm now doing this

Pull your intake plenums and remove/clean/and lubricate with dielectric grease all 3 of the plastic coated nuts on the positive cable:
- 1 at the positive jump start point
- 1 on bank 2 next to the ionic current module
- 1 on the left side of the engine wiring harness housing above the starter.

Most often the click and A0C1 error are from high resistance on the starter solenoid cable.


I've fixed this on at least 20 cars in the two years. Even 1 at Troy's that they were beating themselves up over.

and this

Engine ground cable (Nr.3). These are prone to corrode. This cable is found below engine, usually at rear part.
This is the number 3 for the E60 M5
 

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Discussion Starter · #4 · (Edited)
Just to repeat the symptom: When I try to start the car there is just a single click and no crank.

Here is a picture of the old starter in the car. That exposed copper wire seems to be intact and hasn't turned green. I've testing continuity from the battery terminal at the front of the wiring harness (near the LHS front of the plenum) to where it comes out at the back of the wiring harness. I've tested continuity on the wire that goes from that back point on the wiring harness down to the starter. And I've tested continuity on that garbled up piece of copper wire that runs from the solenoid to the starter

Auto part Metal

This next picture is of the new starter.
Auto part Metal


Where I need help:
Is there a way of checking what is happening at the starter in the car using an external power source? Do I run 12V directly to the solenoid? If so, how do I simulate pushing the start button? Is this 12 v through a switch into the black socket?

Is there any risk if, with the engine apart like this, I push the start button to see if there is voltage at the plug that goes into that black plastic socket? Or will the fact that everything is disconnected make this a non-starter.

How can I check that the starter has a ground? There doesn't appear to be any physical (brown wire) one. Is it through the case via the connection with the engine block? Somebody?

Please, someone, help me understand what I need to do here to see if the starter is bad, or the solenoid is bad; or, if the problem is somehow in the wiring on the ground side - because it sure doesn't seem to be a loose connection on the power side.


I found this. Can someone with experience tell me what the risks are of doing this with the starter in the car and the tranny in "N"? Will I hurt anything if I test the starter and it turns? How can I tell when the solenoid clicks, if it has pushed the stater motor pinion (toothed wheel) forward?

Testing the solenoid.
The Solenoid (small cylinder on top) controls the movement of the ‘starter motor pinion’ or the toothed gear that can been seen through the cutout. Connect the black jump lead to the negative (-) terminal of the battery and the other end to the body of the starter motor.

Now connect the red jump lead to the positive (+) terminal of the battery and touch the other end of the lead to the terminal on the back of the solenoid. The solenoid should click loudly and throw the starter motor pinion forward. The starter motor should not turn.

If this does not happen, then the solenoid is faulty.

Testing the starter motor.
Touch the end of the red jump lead onto the large terminal of the starter motor. The shaft should rotate strongly, if no then there is a fault and the entire unit should be replaced.
 

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Discussion Starter · #5 · (Edited)
More information.

1. I hook up red (positive) jumper cable to the big nut on the solenoid and run a wire with small alligator clip into the black plastic socket where the ignition switch signal is supposed to go.

2. I put the black jumper cable on the -tive of the battery and the other end on the ground post that is on the strut tower. I've already tested that the starter is grounded properly to that point - so putting the black jumper cable there is the same as putting it on the body of the starter.

3. I touch the other end of the red jumper cable to +tive batter post and the engine turns - i.e. the starter engages.

Here is a picture of the -tive battery terminal hook up. I've put a red square around the cable clamp hookups.
Electrical wiring Wire Steel Wheel Metal

Here is a picture at the starter. The red +tive clamp is on the main terminal on the solenoid, and there is a smaller jumper cable going into the "ignition signal" socket which is hi-lighted by a big red box.
Auto part Fuel line Engine Automotive engine part Vehicle

Here is a video of what happens when I touch the other end of the red cable to the +tive terminal on the battery. Notice how the stater turns. [Video coming whenever Youtube gets off their collective @SS].
+ https://www.youtube.com/watch?v=nCPKMnZBWJU" title="View this video at YouTube in a new window or tab" target="_blank">YouTube Video
https://www.youtube.com/watch?v=nCPKMnZBWJU"> https://www.youtube.com/watch?v=nCPKMnZBWJU" /> ERROR: If you can see this, then YouTube is down or you don't have Flash installed.


Bottom line is that the starter is good. So: Either it is not getting the signal from the ignition - but why would I hear that click? OR..... It's not getting power from the battery, so there is an issue with the cables running from the boost terminal in the engine compartment to the the front of the LHS plenum through the wiring harness to the back of the "valley between the two banks, out and down to the starter. I've checked continuity here in pieces. I guess that I'll have to hook it all up in sequence and check continuity from end to end. Then I'll check if the starter cranks with power applied at the start of that long circuit.

The final test will be to check for a signal on the black plug that is supposed to come from the ignition button - But, again, I'm looking for advice here. I want to make sure that if I hook the battery up in the car, put my foot on the brake, and push the start button, that I won't be damaging anything in order to test for a signal on that black wire.
 

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Discussion Starter · #6 · (Edited)
More information (isn't this fun, kids?)

I hook up the power line from the +tive boost terminal (the one with the red plastic cover in the engine compartment near the LHS strut tower) all the way to the starter - via the wiring harness, just like it is when the car is back together. The signal line is hooked up to the same boost terminal, and so is one end of the red cable.

When I hook the other end up to the batter, I only get a single click at the starter. There is not enough power being drawn to the starter via the normal line. And yet a continuity test shows that it is a circuit. What to do now?

I've hooked up the power and left off the solenoid "ignition" jumper and checked voltage at each terminal. I have full battery voltage all the way to the power terminal on the starter. This means that something is happening when it is drawing power with the ignition signal in place. ANY IDEAS? ANYONE?!!
 

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Discussion Starter · #7 · (Edited)
*crickets*

But it is the long weekend, so I'll put a solution here. This assumes that the 17 mm plastic nuts and attachments have been taken off of the two power terminals at each end on the LHS of the wiring harness plastic case.

1. Loosen the plastic cover on the engine wire harness in the 'valley'. I used a metal pick with 90 degree bend at the end and gently pried up each plastic latch so that it sat above the tab that held it in place. Note that my car had a very small zip tie on the wire bundle that runs into the harness, just beside the +tive terminal at the front LHS - where the cable from the battery boost terminal comes to. I had to cut it off.
You don't need to undo the tabs at the very back on the side that faces the firewall. The cover is very flexible and lifts well enough to get out the big red power cable that you need "de-oxidize"
2. Loosen all the wiring bundles that run over top of the big red battery (power) cable.
3. Use a plastic tool to pop the plastic square that each end of that power cable (i.e. the two terminals) runs through - it should lift easily out of its resting place in a notch in the wiring harness bottom.
4. Remove the big red power cable from the harness case.
5. You will need a 14 mm socket to hold the post steady, while a 13 mm wrench can be used to loosen the nut that is on the inside of the whole "battery post" on each end of this cable.
6. There are many points of contact to get power from the cable out to the next cable, or to take power in from the outside cable. They don't look bad - but trust mean, they are oxidized. Because there are so many surfaces involved here - and the fact that the contact on the inside (wire harness side) may be minimal from movement and vibration over time, it creates a risk of voltage drop from the front end of the cable where it takes power from the battery boost post, to the back of the harness where the cable running to the starter motor is attached. This voltage drop can lead to the single click on attempting to start - even if you have tightened down the two plastic nuts until the car squeals.
SO: Clean every surface that touches every other surface - this includes the battery cable eyelet, the surface of the post that it will sit against, the surface of the nut fixed to the post on the outside of this. I used 400 grade sandpaper. I did the same for the cables that attach to these terminals.

TL;DR: End result is that the car cranks when I do the battery hook up at the front terminal. In theory, it should start once everything is back together.

Take a look at this video and you will see how little oxidation is needed on a surface to surface power exchange to create a resistance and a voltage drop. Now imagine the situation where we have surface to surface to surface to surface at two ends of this cable...

+ https://www.youtube.com/watch?v=ry68G0C2Fyc" title="View this video at YouTube in a new window or tab" target="_blank">YouTube Video
https://www.youtube.com/watch?v=ry68G0C2Fyc"> https://www.youtube.com/watch?v=ry68G0C2Fyc" /> ERROR: If you can see this, then YouTube is down or you don't have Flash installed.


You're welcome.
 

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You might full battery voltage but if there is resistance somewhere you wont get the amperage across when trying to start it. Have you done a voltage drop test? I would do it for both the positive and ground side, and see if that reveals any issues.

EDIT: Haha I guess I should have refreshed the page before posting, left it open before running some errands and didn't get to post till now.
 

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Discussion Starter · #9 ·
You might full battery voltage but if there is resistance somewhere you wont get the amperage across when trying to start it. Have you done a voltage drop test? I would do it for both the positive and ground side, and see if that reveals any issues.

EDIT: Haha I guess I should have refreshed the page before posting, left it open before running some errands and didn't get to post till now.
Yeah. I just kept plowing ahead. Moral of this story is perseverance. And, don't look for help on a long holiday weekend on this forum (E39 owners, on the other hand...). :devil

Cheers. :cheers:
 

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Discussion Starter · #10 ·
Just to close this thread, the car starts fine. All the plastic and rubber bits have been cleaned and protected in the engine compartment. I still have to put the coolant level sensor on the bottom of the overflow tank back in place (hoops). And, I have a short socket extension + a T-40 socket sitting somewhere on the metal shield down under (double ooops). I imagine that I'll get them back when the rod bearings are done - soon, I hope.
 

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Just to close this thread, the car starts fine. All the plastic and rubber bits have been cleaned and protected in the engine compartment. I still have to put the coolant level sensor on the bottom of the overflow tank back in place (hoops). And, I have a short socket extension + a T-40 socket sitting somewhere on the metal shield down under (double ooops). I imagine that I'll get them back when the rod bearings are done - soon, I hope.
I would find the socket extension. I might come out and fly in somebody's face on the highway.....
 

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Discussion Starter · #12 ·
I would find the socket extension. I might come out and fly in somebody's face on the highway.....

Of course.

But, I would like to see the physics behind how a small object would fall 2 inches while moving forward and gain enough kinetic energy to bounce up 5 feet backwards.
 

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Classic no crank, no start with a single click heard. I've read all the threads on this and I will be taking off the plenum(s) to check on the battery cable in the valley of the engine - and checking power to the starter and starter solenoid. But, here are some interesting things that may or may not be related.

1. Here is a picture of the battery. there is a plug with a blue and red wire that is just sitting there. Does anyone know what this is for?
View attachment 780337

2. Used ISTA/D (Rheingold) to check on the various buses and modules, and see fault errors. I did this twice

2.1 The first time RLS, ACSN/MRS; and CON showed red i.e. not communicating. CAS, IHKA, and SINE show faults. The CAS error is "Terminal 50 at CAS"

2.2 The second time it was RLS, ACSM/MRS; AMP_0x37; and CID that showed red. the same 3 modules with faults. The CAS fault was A0C1 CAS: Output, terminal 50. I also have 9D12 SINE: Internal Battery; and E71D Auxiliary water pump message error.

2.3 There were other module issues but they got truncated on the printout which I didn't see until I had put everything away. (Not to sell - print landscape in ISTA).

I may have 2.1 and 2.2 reversed - but the point is that things changed from one test to the next without clearing anything. To my E60-novice brain, this seems like some kind of power issue.

I checked power at the battery - strong over 12 volts. The same thing at the main terminal in the engine, and at the terminal near the LHS hookup near the plenum.



What I plan to do is take out everything as if I'm going to change the starter and test the 3rd terminal in the valley and then check the starter and its solenoid. I have a replacement in my parts cupboard if I need it.

Given how the modules showing as RED in ISTA changed one test to the next, I suspect something electronic - and I'm a little out of my depth here, but it sure seems like power isn't getting where its needed as opposed to a mechanical failure.

Does anyone have any other suggestions or things to try - possible relays, fuses, etc that I should check? I could really use your input and advice. Thanks.



What is that plug with the blue and red wire for ?
 

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If I remember correctly it is where a device is connected to deactivate the battery when the car is being transported on the boat.
 

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Thank you for showing this, the starter relay was overloaded here. I bet you are not getting 12V to the starter's solenoid now. If you want to bypass this until you have a chance to fix it, try to jump CAS pin 21 and pin 22 for a few seconds while pushing the start button until car start then remove the jumper and repeat every time you want to start the car.
 

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Thank you for showing this, the starter relay was overloaded here. I bet you are not getting 12V to the starter's solenoid now. If you want to bypass this until you have a chance to fix it, try to jump CAS pin 21 and pin 22 for a few seconds while pushing the start button until car start then remove the jumper and repeat every time you want to start the car.
You are correct - no 12 V at the solenoid [white single wire connector]. We were getting a quick 2v max and then 0v.
 
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