Noble1

Doing some exhaust work and found this valve?   Is it an exhaust brake?   
should we fix it or remove it?   It’s fozen now

Ok so we swapped a 13 sp in place of the Eaton automatic.  Well we initially removed the trans computer as well. 
had to jump the starter to start it with a switch.  Most everything works good.  
missies are 

no speedometer.  
no engine brake.  
Engine will only rev to 1750.  
and  no cruse control.  
Ok been using it this way until today   
 

put the trans computer back on the truck and just bolted it under the cab   Hooked the Speedo back up and now we have a speedometer and the engine will run up to 2100   
 

my question is can we jumper some of the transmission sensor wiring to make it think it’s in a gear so the cruse and Jake will work?
anyone have the schematics of the transmission harness?  
 

Didn’t have time to dig and find relays.  I just put a push button start switch in.  Unhooked the factory wires and taped them up.  Works like a charm.  
mused a 15 amp momentary switch that was already there and some wiring that was installed before we got it for a PTO that was taken off before as well so I only had to splice a few ft of wire.  
 

haven’t hauled a load yet but she seems way more powerful than with the auto.  

Went our local Mack dealer today is Sioux Falls SD and asked them.  Basically got the run around to just bring it to them and it would take a few days and wire harnesses and engineering services or something.  
 

so today we slap it to set her I jump the starter with a screw driver just to test and we take it for a spin to make sure it won’t derate.  Ran good and didn’t have any problems except for the giant hole in the floor yet.  
 

what if I put 2 push buttons in one for the ground and one for the power wire that way it isn’t hooked up all the time only when it starts?   Or do you think it would hurt have the one terminal grounded all the time.  
 

I will dig around for the relays if I get time.  
but we started combining beans today.  
 

I really appreciate the information you guys are giving and look forward to what you find out.  
we just picked up another ch today.  
454 with an 18 spd.  
I will post pictures of our fleet here someday.  

Ok after some more testing with the key on and I put the left side to ground and apply 12 volts to the other side it will crank.  
must be another switch somewhere on the ground.  
so until I find that I in theory could put the left side to a ground and the right side to a keyed power through a push button.  
I will wait until I have help and see if the clutch switch or something else let’s the ground circuit complete before I do the above.  

So the the celinoid one side should be ground and the other a hot when you want it to start.  It started before the trans swap but you had to hold the key for 20 seconds before it would crank.  Maybe there is another safety switch on the ground side possibly?    Would be interesting to look at a schematic.  

Your not talking the big post on the bottom or the front?  
I don’t see a red band either.  

I get 3.4 Volta on the 2 opposing terminals. Neither one does anything when I apply 12 volts 

Mia there like a safety switch on the ground to either one as well?   

Oh have a bush button but how do I hook up the starter?  It won’t do anything with voltage to the two side posts maybe they just need cleaned up. 
I started it befor with a screwdriver across the two big posts.  

Now my Speedo is no worky.  
will have to dig into that some day.  
imagine it got its data from the other trans or something.  

I had my foot on the throttle 

It runs when you jumper the starter.  

Yea 

There isn’t one on the EPDM either for the trans I think that’s why this truck was bought cause there were issues.   
I will try the starter trick.   And see if it fires.  

Well there was no fuse in F71.  
not sure how that is.  
doesn’t look like there ever was.  

No legend.  
do you know what number is fuse 71?

No where is fuse 71?  

What kind of software does it take to hookup and change the onboard computer?  I assume you have to tell it it has a manual trans along with other changes.  I will try jumping the starter after pulling that fuse first

Thanks.  We have 4 Mack’s on our Farm.  The old CH s we have a good old trucks.  This CXU is nice but troublesome.  
I did not pull that fuse, I will and see what happens it doesn’t crank at all.   
 

Have a 2012 CXU had a 3 pedal auto shift that was constant problems.  
swapped it out for a 13sp.  
truck will not start cause it is looking for a nuetral switch or something with the old trans.  What is the best way and proper way to fix this and make it run?