2008 VOLVO VNL 780 - D16 ENGINE NOT CRANKING

[Refuzn-To-Grow-Up]

1 hour ago, rickeieio said:

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?

Hi Rickeieieo:

NEUTRAL SECURED?  I could have shut the engine off while in gear.  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.  

STARTER WIRES:  I just purchased a borescope.  See link below.  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.   Raining all day, so I will do when the rain stops.  

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

 

[Refuzn-To-Grow-Up]

8 hours ago, Wrknrvr said:

 Could we get a picture of the fuse that is involved?

 

8 hours ago, Wrknrvr said:

I am not that computer savvy and I am only being allowed to post one photo.  I have six photos.

 

[NeverEasy]

jRefuzn,  Would you look at the cover for your fuse panel and see if there is a relay marked as start relay?

Chet

[Refuzn-To-Grow-Up]

20 hours ago, NeverEasy said:

jRefuzn,  Would you look at the cover for your fuse panel and see if there is a relay marked as start relay?

Chet

Chet, I just sent you a PM.  I tried attaching the photo of the fuse panel to the PM, but the photo was too large.

I am still trying to find out how to post large photos

[Jaydrvr]

1 hour ago, Refuzn-To-Grow-Up said:

Chet, I just sent you a PM.  I tried attaching the photo of the fuse panel to the PM, but the photo was too large.

I am still trying to find out how to post large photos

Start with this..

 

Once you've created a link from that, use the OTHER MEDIA tab to inset your new link where it says insert image from URL. You'll need to strip off the [IMG] from the front and back first. Jay

[Refuzn-To-Grow-Up]

On 1/20/2024 at 7:06 PM, NeverEasy said:

jRefuzn,  Would you look at the cover for your fuse panel and see if there is a relay marked as start relay?

Chet

If I did it correctly, below is a link to a photo of the back of the fuse panel.

[IMG]https://i.imgur.com/VSIk2Jwl.jpg[/IMG]

[Refuzn-To-Grow-Up]

On 1/20/2024 at 7:06 PM, NeverEasy said:

jRefuzn,  Would you look at the cover for your fuse panel and see if there is a relay marked as start relay?

Chet

[Jaydrvr]

11 hours ago, Refuzn-To-Grow-Up said:

Duplicate

 

Edited January 22 by Jaydrvr

[Refuzn-To-Grow-Up]

Yesterday, I was going to install the Meg fuse holders when I noticed that the nuts were not in the packages.  I drove back to the Volvo dealer and was told that I have to buy the nuts separately.  

When I screwed the nuts onto the fuse holder, there was extreme resistance at the very end.  The parts guy told me they are lock nuts.  These nuts are the type of lock nuts that has the ending threads mechanically "deformed."  I do not like these nuts because they damage the bolt threads.  So, I decided to buy nylok (250F temperature rating) from McMaster Carr.  Nuts should be here in a couple of days.

For those of you folks who never heard of McMaster Carr, I have used them for years.  They sell quality parts and ship (usually within a few days) to me for a reasonable price.  Here is a link to their website.  https://www.mcmaster.com/

[NeverEasy]

Where I can, i use stainless steel star washers. I am looking for the best contact possible. On your fuse holder, I would put a star washer on the stud, the cable, another star washer and then the nut.  And then I spray with battery terminal cleaner and follow that up battery terminal protector.  Even though the connection is not at the battery, the electrolysis that causes the green corrosion is still there, more prominently on the positve side.

Before you start connecting things up, spray the components with terminal cleaner and see where the acid is waiting to cause problems.

 

 

[Randyretired]

Star washers can help in some instances but high amperage connections often need full contact to carry the load.  In these circumstances direct contact with the matting surface is important.  Depending on the surface I often like to make sure everything is flat, no ridges and maybe lightly sand or buff the contact areas.

[rickeieio]

7 hours ago, Randyretired said:

Depending on the surface I often like to make sure everything is flat, no ridges and maybe lightly sand or buff the contact areas.

See first post on page two.  Sick minds think alike.  😁

[rickeieio]

Progress report?

[Refuzn-To-Grow-Up]

2 hours ago, rickeieio said:

Progress report?

Fuse holders and fuses replaced.  Battery cable terminals cleaned.  No change.  :(

I decided to seek help because I am "over my head" and too busy to diagnose the problem.  I reached out to one of my fellow gearhead friends (local to me) and he referred me to Jim, his diesel mechanic friend who works on big diesel trucks.

This past Thursday, I spoke to Jim and I told Jim the following:  I have a 2008 Volvo with a 16 liter engine.  The Volvo spent its working life in Canada (lots of snow).  Battery cable ends were seriously corroded.  When I try to crank the engine, the starter does not crank (nothing) and the dash lights go completely out.  Volvo always seemed to be "slow" cranking as if the starter motor was struggling.  

Jim, like most of you, said it sounds like internal cable corrosion in the big (high amp carrying) cables (positive and/or negative).  He said the corrosion is not apparent because the cable to lug crimp area is covered (appears to be shrink tubing).  He is coming by the house next week to work on the problem.  He has the equipment to make new cables. 

Based upon what you folks have told me and what Jim told me, I am going to have him replace ALL of the high current cables (and any others Jim recommends) because this internal cable corrosion sounds like an electrical issue with the Volvos, as they age.  When I eventually sell the Volvo, the new owner will love me.  LOL.

I am very thankful that I was not on the road when this happened to me.

I will keep you posted and thanks to all of you for the help.

Safe Travels.

 

[rickeieio]

45 minutes ago, Refuzn-To-Grow-Up said:

I am going to have him replace ALL of the high current cables

He'll likely do a voltage drop test over each cable, which will point out which are bad, or not.  There's no sense in throwing money at a cable that tests good.  Oh, it's not just a Volvo problem.  They all do it.

For the record, I'll say again, at least part of the problem is where all those wires come together at the starter solenoid.  This whole problem could be as simple as tightening one nut.  Don't keep throwing money away until you've eliminated the easy, and cheap stuff.

[NeverEasy]

For the record, there is more to starting the trucks than the big cables running between the starter and the batteries.  The recognizable sign is that the dash lights go out when the key is turned. That indicates a high resistance connection on either the 12 Volt or ground going to the dashboard.  The electrical theory is a high resistance will permit the low amperage lights to work like it was an open circuit.  Any larger amount of current (I = E/R) causes a large increase in the voltage drop across the bad connection and that resistance becomes a large resistance in serial with the dash lights and the lights can not get enough voltage to work.  I can draw up the schematic for such a problem if anyone wants to challenge my theory.

This simple rig up may show that there is a high resistance connection to the dashboard.  Hook something like a lamp cord (14 AWG or better), one positive to the battery bus, the other end of that to the CB radio positive post.  One wire to the battery negative bus and the other to the CB negative post.  I have asked you to do this non-invasive test before but you have yet to say , "I tried it".  Why not?

If you don't do this test, you are wasting time and resources chasing big cable problems that may or may not exist. I have fixed more than one truck with this simple work around.  

Chet

 

 

 

[NeverEasy]

I am now certain that the issue is in a bad ground or hot wire to the dash.  I drew up this schematic and discussion.  It should be noted that the lights on the dash going out is the prime reason that the big cables are not an issue AT THIS POINT.

 

[Refuzn-To-Grow-Up]

FINAL STATUS:  The truck is fixed. 😀

THE REPAIR:  Using an electric drill and a wire brush, cleaned the corrosion off of the starter motor cable (positive and negative) lugs.  Replaced the corroded starter nut that secured the cable to the starter motor

THE TRUCK:  2008 Volvo 780 VNL with a D16 engine with about 700,000 miles.  It spent its working life in the snow country of Canada.  

THE PROBLEM:  When I turned the ignition key to start the engine, the dash lights went out (instantly) and the  starter motor did NOTHING!

AFTERTHOUGHTS:  Given my work load and my skill level (or lack thereof), I knew that I was in over my head.  So, I reached out to friends for a referral to a good diesel mechanic.  And, I found one.  His initial thought was that it sounds like poor cable connections on the starter motor.  He load tested the batteries.  At the batteries, he checked all cables to verify correct polarity.  He checked all of the fuses (in the dash fuse panel).  He cleaned the , cable lug connections on the alternator.  Then, he removed the cables from the starter.  I have no idea how he did that because the starter is "buried" on the right side of the engine. He wire brushed the starter cable lugs and installed a new nut.

When I first bought the truck, I had the dealer install a shut off switch.  The dealer wired the starter motor cable through the shut off switch.  When I replaced the batteries, I removed the starter motor cable from the switch because of the high starter current.  The mechanic confirmed my concern and told me that the cable should not go through the switch.  

I wire brushed all of the heavily corroded cables lugs in the battery compartment.  I replaced the heavily corroded mega fuse holders (also in battery compartment) and the mega fuses.  

For the last few years, the starter sounded like it was struggling to crank the engine.  Now, it cranks the motor over really "snappy."

One of the AWESOME things about the HDT forum is that we share our knowledge.  So, I wanted to share what I have learned so that others will be able to fix their HDT's.

 

[dblr]

Thanks for sharing the outcome and glad your back up and running!!!!!!  Your also right the knowledge here is fantastic and I know it helped me when making the HDT decision.

Edited February 9 by dblr

[rpsinc]

Although my experience with high output cables in NOT with trucks and starters, but rather welding.  IF I am welding for extended periods of time and my stinger is getting hot, sometimes too hot to hold, so I am not welding at that time, it is usually the ground cable connection.  It has been a common task to cut off the end of the cable which usually has many strands of that cable broken, often the result of winding up the cables or just the moving of the ground clamp during it s work, and then using a bit of copper plumbing pipe as a clamp between the clamp screw and the cable end, I can make it up as a clean connection with all the strands working in "harmony" and no more hot stinger and back to work completing my job.

It stands to reason that the problem in Jim's truck was like this, esp with high draw(starter circuit) and compromised cable end = resistance, which those electrical circuits dont like.

Thanks for the update and safe travels.  Now get on out there Jim.

[Refuzn-To-Grow-Up]

16 hours ago, dblr said:

Thanks for sharing the outcome and glad your back up and running!!!!!!  Your also right the knowledge here is fantastic and I know it helped me when making the HDT decision.

I have taken a lot (information and help) from this forum.  It took me about an hour to reflect and summarize what happened.  I felt that I owed it to this group of folks.

BTW - the other thing that I learned is when I am "over my head" to get local help.  A good way to do that is to send a bcc email (or text) to fellow local gearheads and ask for help.  And, that is how I found the mechanic who fixed my Volvo.