Wirlybird

46 minutes ago, JoeH said:

Never heard of the 901 part of it.

I'll have to ask my friend about it.
I'll look for those plastic lines, when it warms up a bit, but I don't recall seeing them.

12 hours ago, JoeH said:

Not sure what the E6901 is. Is this an E6 engine? Or an endt675/6 engine?

The ENDT engines use  plastic fuel return leak off lines that jump from injector to injector and then run back down to the injection pump/fuel return I believe.  These lines get brittle and crack eventually, and 99 times out of 100 I'd bet this is the cause for draining off fuel when sitting. Easy enough to buy a coil of this stuff from your Mack dealer and replace any that are damp.

My friend said the E6901 was the engine.  It is on a plaque on the hood.

3 hours ago, Vladislav said:

All is done the right way! Great to learn the problem is solved.

If you're going to use the truck in the future and taking to account that machine isn't new it worth to remove the starter and go through it completely. Mostly for cheking contition of the brushes and shaft bushings and also for cleaning and grease. These starters seem able to work for really long time. But preventive service would minimize chances of unexpected failure.

Actually the starter was redone about a year ago.  that's why it was a little disappointing to find the loose connection.  This truck is an old oil field winch truck so it sees pretty harsh conditions!  I am sure it shakes everything loose.

Parts are ordered for the fuel supply pump and then we can get it started again.  She always drains off the fuel when sitting for periods.

1 hour ago, Freightrain said:

You are getting continuity from the left post to ground because that is the power lead to the windings and they go to ground.  If you had the proper meter it would give a specific resistance reading for the windings.

 

I've never personally had that solenoid apart so I can't confirm or deny what you will get once you pop it apart.  I know the basics of what it should have to function.

I had my meter on 2k setting which gives a tone as I couldn't see the meter while hanging over the fender to get to the terminals!
Also I was first trying to see if I had a dead short in the starter motor.

3 hours ago, Freightrain said:

The red is the hot from the battery which connects to one side of the contacts inside.  The yellow is the lead into the windings of the motor.  The small wire is the coil to the solenoid which when powered pulls the contacts closed and connects the main power to the windings.

 

Sounds like the contacts are burnt in the solenoid, which would make the starter not run.  That is the flash you are seeing.  Or, the motor is bad(shorted) and the flash is the high current when applying power to the bad motor.

Removing the screws, there is a spring loaded plunger inside, so be careful that it doesn't pop apart and things fall out.

Yes the block side bolt is a PITA to get out.  Either a box wrench and just 1/16 turn at a time or swivel socket and get out enough to use a rachet.

 

Besides it weighs a ton to hold onto.  My B is a real bitch because it is a lower right side starter and it falls in your face if you don't get a hold of it.  Reinstalling is another WTF moment.

Ok, to clarify, I can take the plate with the terminals on it off the back of the solenoid ok?  Just concerned it will come apart and have to pull the starter.

Hoping that it is bad contacts and I can replace without pulling the starter.

1 hour ago, Brocky said:

Before you dig deeper, take all the wires off (including the 90* brass strap to the starter housing) and CLEAN all the surfaces with a file or emery cloth to make sure you are getting good contacts.. I have seen many times where  1/16th turn on a nut cures the no start problem..

Yes, going to finish removing the strap and small wires to test and see if I can determine why I get continuity from the left post to ground with batteries unhooked.

1 hour ago, Freightrain said:

The red is the hot from the battery which connects to one side of the contacts inside.  The yellow is the lead into the windings of the motor.  The small wire is the coil to the solenoid which when powered pulls the contacts closed and connects the main power to the windings.

 

Sounds like the contacts are burnt in the solenoid, which would make the starter not run.  That is the flash you are seeing.  Or, the motor is bad(shorted) and the flash is the high current when applying power to the bad motor.

Removing the screws, there is a spring loaded plunger inside, so be careful that it doesn't pop apart and things fall out.

Yes the block side bolt is a PITA to get out.  Either a box wrench and just 1/16 turn at a time or swivel socket and get out enough to use a rachet.

 

Besides it weighs a ton to hold onto.  My B is a real bitch because it is a lower right side starter and it falls in your face if you don't get a hold of it.  Reinstalling is another WTF moment.

Thanks, I am hoping that the solenoid shows as grounding from the post with he yellow and I can take the rear plate off.
My friend said he uses a swivel on the engine side and it is turn a tiny bit, remove and reset and do it again.  He's had it out a few times.

At firs we would get  a "click" when trying to start, like the solenoid engaging but not turning the starter.  A little rapping on the start and it would go.  the last few times though we got that arcing and I didn't see anything obvious on the outside so we gave up for the day.  Going to be a cold on today so don't know how much we'll get done.

Need to get the starter (40MT starter) out on this Mack and my friend says that last time is was a major undertaking.  Said the bold on the engine side was extremely hard to get on.

Reason to take it out is I think we have a bad solenoid.  We get an arc at the back of the solenoid when turning the key.  The arcing is in the area of the red arrow.
I tested for continuity to ground at the terminal by the red arrow that goes into the starter and got it, and also tested at the yellow arrow and the same which I expected since they are connected.

I will remove the strap between those two terminals tomorrow to see if continuity is at the terminal on the start or on the solenoid.
It seems I need to remove the starter to remove the whole solenoid.  I am wondering if the plate on the rear of the solenoid that has the terminals can be removed without part flying everywhere!

Thanks for any suggestion, tips or advice.

9 hours ago, Vladislav said:

Thank you for improving my linguistic skills ones more, gentlemen!

In this particular case I figured it worth better investigation (for me to learn the lesson essentially) so made a bit of Google search. I figured from there that buss bar (bus bar also looks correct) and a junction block are not almost the same matter. Definitely both are a bar with a line of terminals. But buss bar is a solid metal bar with multiple connectors. So my understanding is it's for connecting multiple wires to the same potential providing minimal resistance between the terminals. This way it can't be used to connect contacts of different circuits and seldom used in automotive products (and that's why I never met the term). A junction block has every terminal electrically insulated from the others so its function is different.

Please correct me if I'm wrong since that's how I understood the subject but never used the term in practice before. My dad likes to joke that a person who tends to teach doesn't know the matter himself in many cases. And this time I'm just in a half of a step to be such the person

I think you are right.  Busbar or Bus Bar is how I find it and it seems that the specific use would be as a "power" supply or distribution point where one power line in and many possible lines out.

Terminal block or junction block would be a series of individual/independent "terminals".

I think on the Mack the terminal/junction block is used as a point where the fender wiring can easily be disconnected from the main harness.  In this case it enables you to undo the main harness connection to the headlight, blinker and parking light for the fender and then be able to remove the whole fender and its wiring as one unit.

I've always used the term Busbar in a generic way to mean a strip of terminals or connection points.

1 hour ago, Brocky said:

Vlad, He left off an "s".. He means buss bar, as in big junction block..

You are correct!!  My oversight!

19 hours ago, Vladislav said:

What bus that bus bar came from??

Sorry I'm not a native bus specialist

The "buss bar" is just the terminal block on the inner fenderwell located near the radiator.

No kidding!  That buss bar was still a pain to get to.

Got the new adjusters into the buckets and new headlights in on both sides.

57 minutes ago, mechohaulic said:

if the housing was changed with an after market replacement, the headlight ground may have a pop-rivet to the assembly which isn't completing a good ground.

The passenger side was replaced and could be one of the aftermarket mounts but looks like a newer Mack replacement.

Will be checking grounds

Thanks guys.  First thing I know is the passenger side light, housing and all has been changed so that is suspect!

Wondering about the light switch and dimmer.

I read that the light switch can be an issue on older Mack's.

What is odd is why the passenger light would go out if the driver bulb is disconnected/removed?

New headlight bulbs (H6024's) and now we have an issue.  Issues is with the old sealed beams also, so all 4 act as described below.

Driver light is good and bright.

Passenger light is dim.

Unplug driver headlight and the passenger light goes out!

Both headlamps test fine on drivers side.

Both are dim on passenger side.

Apparently lights worked ok until someone might have messed with wiring at the firewall.  Or maybe just age and from sitting?

Going to start troubleshooting tomorrow weather permitting.

Turns out all I needed was the plastic aiming part and aiming the screws.

Now those are kind of cool!

I think I found the right hardware on line.  We'll see how it does once it arrives.

UPDATE:

Now that I have a closer look the parts I actually need are the plastic stand-offs for the adjuster screws, the adjuster screws and the springs.

So far I have not found these.

I did find replacement headlight cups but they don't have any of the hardware.

Now I'm looking for a headlight mounting cup.  One of mine the plastic standoffs are broken so the headlight won't mount.

Should I just look for something generic?

52 minutes ago, JoeH said:

If I had a 1908 I don't think I'd be driving at night, I'd be too afraid of hitting a deer!

No kidding!  I fixed the year!

Wow!  Looked those up and $350 each!  Think I need a more cost-effective option!  It may be new sealed beans!

We need new headlights on the Mack and would like something brighter than the original sealed beams.

Any ideas on upgrades or kits to replace the original round lights?

Thanks.

Thank you!  We'll take a look once the temp get up a bit.