2008 VOLVO VNL 780 - D16 ENGINE NOT CRANKING

[rickeieio]

You're getting there.  Don't give up.  Keep removing/inspecting/cleaning, on up the current stream.  Remember that connections need to both clean and flat.  Fittings that are bent/twisted need to be straightened to make the best contact.

My money's still on the stack of connections at the starter solenoid.  Lots of wires coming together there, both positive and ground.

[Refuzn-To-Grow-Up]

On 1/13/2024 at 7:54 PM, Jaydrvr said:

Since the voltage is not dropping when you turn the key, it appears you're not getting any current to the starter. That suggests to me that your starter relay isn't working. It's on the front side of the firewall, just down and to the right (passenger side) of the steering column - at least on my first gen truck, plus others I've seen. 

I was unable to locate the relay on the firewall.  So, I did some research on purchasing a starter motor for a 2008 VNL D16 Volvo engine and it appears that the relay is bolted onto the starter motor.  See the Delco Remy link below.  

I am so thankful that this occured at home and not on a trip.

https://www.delcoremy.com/find-a-part/product-details/8200469

[NeverEasy]

A new starter is a big leap in troubleshooting this problem.  I sent you electrical schematics. I can't be sure that they apply to your truck, yet, so some caution is necessary.

Print pages 7,8, and 10.  Those are sheets AA, AB, and AD.  I tell you that so you can trace out your system via the labels on where wires go to another sheet listed by Alpha Characters and position indicators. 

How it works. The relay on the starter is shown one AD.  The ground side is attached to the starter's ground. When energized, that simply sends a ground to (Volvo Engine box on schematic) Relay RLY40-pin 85 inside the truck.  RLY40 is energized if the transmission is happy for the truck to start and the ignition key is turned on.  Whichever transmission you have will send 12VDC on Wire 284 to close the RLY40 on pin 86.  With RLY40 closed, it sends 12VDC to the starter solenoid to start the truck.

Note that the schematic shows Wire 285A coming out of RLY40, pin 87.  it points to schematic sheet position AB:3B.  Going to sheet AB and running across to position 3 and down to position B, you will see that the 12VDC comes from XP2 Power Stud.  That is one of two Power Studs that gets power from the batteries via fusible link wire.

Now, where does that take us?  If this schematic is relevant to your truck, I would pull RLY40.  Meter pin 87 for 12VDC.  That comes directly from XP2 which is battery voltage.  With the transmission in neutral and ignition on, use a 12AWG wire and manually connect RLY40 pins 30 to 87.  The starter solenoid will get 12VDC and the starter should start the truck.  That is as close as you will come to bypassing a lot of transmission, ECU, and ignition problems.  

[Refuzn-To-Grow-Up]

3 hours ago, NeverEasy said:

A new starter is a big leap in troubleshooting this problem.  I sent you electrical schematics. I can't be sure that they apply to your truck, yet, so some caution is necessary.

Good Morning Chet:

There is NO WAY that I will get under the truck to change the starter.  See my earlier post on the horrible death of my friend Mark.  If I can't fix this problem, without going under the truck, then the truck is off to the shop and I will have to "shake some cash out of the money tree."

The ONLY purpose of looking into the purchase of a new starter was to investigate whether the relay that activates the starter solenoid was located on the starter motor (or on the firewall as in some Volvos).   I watched several videos diagnosing starter problems (for the D16 engine) and I observed what appeared to be a relay bolted onto the starter motor.  Since, I could not locate a relay on the firewall, I went down the "rabbit hole" to see what is supplied with a new starter.  The photo of the starter shows a relay bolted to the starter motor.  If I knew someone who worked in the parts depatment of a Volvo dealer, I would ask them to look up the starter in their parts computer and print me the pictorial of the starter.  

For other HDT members, who own a 2008 780, VNL with the D16 engine, the starter solenoid relay MAY be  bolted to the starter motor.  But, I am still researching.

If/when the starter motor is replaced AND if the relay is bolted to the starter motor, I will ask my mechanic to relocate the relay from the starter motor to the firewall. 

Today, I will do a more careful inspection of the firewall for a relay.  It would be wonderful if the relay is on the firewall.  I will also clean up the firewall pass through terminals/connections.

[Refuzn-To-Grow-Up]

Chet, thanks for the info.  I will follow your troubleshooting instructions.

[rickeieio]

Granted, I've not seen every starter, but I've yet to see a commercial truck (electric) starter that didn't have the solenoid incorporated into it.  There's no functional way to separate the two.

BUT, I wrote solenoid, not relay.  There is a solenoid on the starter, and possibly a relay up stream from that.  What you're seeing in videos is not a relay, but a solenoid.

That said, you need not get under the truck to access the end of the solenoid where all the wires connect.  While perhaps difficult, it can be done from above.

Just continue with cleaning the contacts on ALL the wires and likely your problem will be fixed, no parts required.

Edited January 16 by rickeieio

[Wrknrvr]

   I tried to paste a picture of a starter. It did not work.

 

   I am not a real computer person, so I sent it out to be displayed, by a smarter person than me.

[NeverEasy]

Go to this link:  http://photoposting.is-great.net/?i=1

Drag and drop a picture as it says.  I link to the picture will appear.  Copy that link. Open Other Media in the bottom right.  and paste it to  the URL to "Insert Image from URL.  The delete leading and trailing [ just leaving a bare URL. Then clicck Insert IN Post.

 

 

[NeverEasy]

The starter solenoid must be mounted on the starter.  The amount of current passing through it is too high to be remotely located

.

 

[Wrknrvr]

   The file for the photo is to big to copy and paste. I did state I am not a computer person? At all

  search for Delco 39 Mt starter

 

   I just searched this on google. It shows a starter with a solenoid and a relay on top of it.

  I have never seen one of these. 

Edited January 17 by Wrknrvr

[Refuzn-To-Grow-Up]

Thanks for staying with me.  I am working on the Volvo as work permits. 

I located the studs on the firewall.  They were behind the steering column.  They look as nasty as the other connections.  See photos.  I did not see any studs on the right side.  I will check again, as time allows.  

I removed the right steps cover and was able to gain access to under the truck (without too much anxiety).  There was lots of room above me.  I did not bring a flashlight (DAHHH!) with me.  The starter looks like it might be on the right side of the engine on the D16.  I noticed humongous cables going to the right side of the engine.  They were covered in dirt and muck, but I think that these are the large (positive and negative) cables coming from the battery.  I will clean a spot up and see if they are red and black.

Gotta get back to work . . . . just in case I have to have the Big Boy towed to my mechanic to fix.

[Refuzn-To-Grow-Up]

42 minutes ago, Wrknrvr said:

   I just searched this on google. It shows a starter with a solenoid and a relay on top of it.

  I have never seen one of these. 

Yeah, that is what I was finding.  Volvo should have put the relay on the firewall, just like what you folks are telling me.  Lucky me.  LOL.  

[Refuzn-To-Grow-Up]

3 hours ago, NeverEasy said:

The starter solenoid must be mounted on the starter.  The amount of current passing through it is too high to be remotely located

.

 

Yes, I agree.  The solenoid is mounted on the starter.  BUT, it appears that the relay that activates the solenoid is also mounted on the starter, as opposed to the firewall.

If i can get to the starter motor, I will take a photo with my I-phone.  If not, then I am thinking about buying one of those cameras that will allow me to "snake" the camera down to the starter connections and take a picture.  As an admitted "Tool-O-Holic," ya can't have too many kool tools.

[Wrknrvr]

Years ago on this forum I think there was a replacement that was gear drive, for truck engine. I think they were Densco?

  But I did find this for Volvo truck engines.

BBB Part Number: 137179-05760189

 

[Wrknrvr]

    The studs you are showing do need cleaned.     I am also thinking there is a heat actuated device on the starter??? To keep from over heating the starter. As in you keep cranking the engine for more than it should. That could be bad?

    You could have more than one thing being causing the problem?

 

   Check the net for Wilson rebuilt starter for your truck.  You could maybe give them a call, and ask for a specific wiring diagram for your truck? That could be a long shot, but when your desperate, anything that helps is welcomed.

   Is there anything on the HDT forum about the wiring diagram. It maybe on Mark Bruss site?

 

   Does the on board diagnostics say anything?

[Refuzn-To-Grow-Up]

7 hours ago, Wrknrvr said:

Is there anything on the HDT forum about the wiring diagram. It maybe on Mark Bruss site?

Does the on board diagnostics say anything?

I'll check Mark Buss' website.

Only diagnostics are low system air pressure and low transmission air pressure.

[Jaydrvr]

11 hours ago, Wrknrvr said:

Years ago on this forum I think there was a replacement that was gear drive, for truck engine. I think they were Densco?

  But I did find this for Volvo truck engines.

BBB Part Number: 137179-05760189

 

Mitsubishi and others make a gear reduction starter, definitely the cool way to go. They're half the weight, easier to install, lower current draw, higher spin speed and have an awesome sound. Jay

[Refuzn-To-Grow-Up]

Well, today was an adventure!  I decided to check out and clean up the connections on the mega fuses.  A simple project.  LOL. The positive and the negative cables, from the battery, are wired directly to to the mega fuse.  Then the fused side of the mega fuse feeds the truck.

The nuts, securing the cables, were so corroded that I could not remove them.  So, I cut the studs off to free the cables.  Shesh!  The bolts securing the mega fuses to a mounting plate also had to be cut off.  All of this corrosion may not be the problem, but as long as I am in this far, I may as well clean it all up.  When I eventually sell the Big Boy, the new owners will love me for cleaning up everything.

The fuse on the positive cable is black and has the following markings:  Buss AMG 150A 32V.  I am assuming that is a 150 amp fuse made by Bussman.  The fuse on the negative cable is reddish in color and is marked 400A 32V.  There are no manufacturer markings (China?).  I am assuming that this fuse is a 400 amp fuse.  

I am no electronics genius (far from it).  I do not understand why the positive cable is fused at 150 amps and the negative cable is fused at 400 amps.  The way the fuses are wired (immediately from the positive and negative terminals of the battery), it would seem to me that the current going through the positive cable is the same as the current going through the negative cable.  Therefore, the fuses amperage rating should be the same.

Anybody have any idea how many amps the starter motor draws when it is turning over a 16 liter (976 cubic inches) diesel engine?

I am on my way to the Volvo dealer to buy new maga fuses holders and fuses.  Hopefully, their parts computer should be able to tell me what the fuse amperage is for the two fuses.  

[NeverEasy]

Would not matter.  150 amp blows first.  No amperage through the system. 400 amp fuse is doing nothing.  Would not know why both positive and negative are fused.  

[Refuzn-To-Grow-Up]

Thanks Chet.  That clears up some confusion on my part.

I just returned from Volvo.  I looked for an "old dog" with the hopes that he knew how to work the parts computer, and he did.  The parts diagram, for my Volvo, did not show the mega fuse, so he went back to the parts house, pulled a fuse holder and used the part number to find where used on my Volvo.

Per Volvo, the fuse rating is "from 150 amps to 400 amps."  So he went out to the shop and asked a mechanic, who said 150 amps in both fuse holders.  

Hopefully, I will get installed this weekend

[Wrknrvr]

   I am curious?

 

   Could we get  a picture of your starter?

 

   And a picture of the fuse that is involved.

Edited January 20 by Wrknrvr

[rpsinc]

Jim-  while doing all you are to get those electrical issues corrected, as long as the truck is showing "Neutral Not Secured" and air issues, I dont believe it will allow the starting circuit to engage to start the engine, no matter a D16 or D13.  

If I remember correctly from my own troubleshooting, certain actions must be taken before the truck starter is allowed to engage.  Air to the trans etc is a part of those actions.  I have read on Volvo pages that sometimes drivers have inadvertently shut the truck down while in gear and then when the truck leaked air below its required minimum, the truck isnt in N so that action not being satisfied, does not allow the circuits to allow the starter to become available to start.  In those cases, it appears that road side service airs up the truck and allows the air operated shifter to satisfy the N transmision requirement.  

Only offering a possibility.  It seems that you have been able to eliminate the TCM as a likely culprit, which was my issue.

[rickeieio]

I've read through this thread twice, and am still unclear as to whether you are sure the truck is in "N", and displays such a message.  Having that little "N" for the starter circuit to access is very important.  Been there, have the cancelled checks.

If indeed, you are sure you have neutral, then continue cleaning terminals.   Oh, and btw, have you grabbed that mess-o-wires at the starter solenoid to see if they're all tight yet?

[Refuzn-To-Grow-Up]

7 hours ago, Wrknrvr said:

   Could we get  a picture of your starter?

   And a picture of the fuse that is involved.

STARTER PHOTOS:  I just purchased a borescope.  See link below.  I have been meaning to buy one of these for years.  I could not pass up the "half price deal" on it.  I was practicing with the borescope last night.  I should be able to snake the camera down to the starter and get some nice close up photos of the motor and the cable connections.  I wish that I had the borescope, to inspect the fuses, before I violently (see below) removed them.  Raining all day, so I will do when the rain stops.  

 https://depstech.com/products/endoscope-with-screen-ds700-triple-lens

FUSE INVOLVED:  I tried to attach photos of the fuses, fuse block and cable end, but the files were too large.  I will try again.

NOTE:  The nuts securing the cables to the fuse block was so corroded that I had to use a mini impact wrench to remove the nuts.  This mechanically damaged the fuses and the holders.  But the 150 amp fuse looks like it had been heat damaged.  I had to cut up the fuse holders to remove them from the mounting plate.

 

[Refuzn-To-Grow-Up]

2 hours ago, rpsinc said:

Jim-  while doing all you are to get those electrical issues corrected, as long as the truck is showing "Neutral Not Secured" and air issues, I dont believe it will allow the starting circuit to engage to start the engine, no matter a D16 or D13.  

If I remember correctly from my own troubleshooting, certain actions must be taken before the truck starter is allowed to engage.  Air to the trans etc is a part of those actions.  I have read on Volvo pages that sometimes drivers have inadvertently shut the truck down while in gear and then when the truck leaked air below its required minimum, the truck isnt in N so that action not being satisfied, does not allow the circuits to allow the starter to become available to start.  In those cases, it appears that road side service airs up the truck and allows the air operated shifter to satisfy the N transmision requirement.  

Only offering a possibility.  It seems that you have been able to eliminate the TCM as a likely culprit, which was my issue.

Hi Marcel:  Yes, I could have shut the engine off while in gear.  I have had my DAHH moments in life.  The dash indicator shows when I shift the gear shifter from drive to neutral.  BUT . . .  I suspect (but could be wrong) that there is another sensor, inside the transmission, to make sure that the tranny is, in fact, in neutral, before allowing the engine to start.  

The Volvo is at my house and the trailer is in storage.  I tried to air up the Volvo system with my home compressor, but the compressor is old and could not reach the required air pressure to shift the tranny into gear and back to neutral.  I have a compressor in the trailer that will do the job.  I just have bring it home.  

As I recall, prior to starting the engine, the tranny has to be in neutral AND the brake pedal has to be depressed.