Glensts

On my 79 there was an air pressure switch under the hood attached to the brake treadle valve.  Just 2 wires and one had constant power and one went to the lights.  

Don’t have answer but will tell my version.  Mp8 water in fuel light come on, (ended up being bad sensor) so changed fuel filters and added a water dispursement liquid that is made by a company that also makes our antigel for winter months.  Never used this product before and won’t again.     Drive for 2 hours and it loses power, make it home change fuel filters and goes great for 2 hours.   Shut off. No filters with me.      Restart and goes great for 2 hours.    Restart then good for 2 hours again,   I see the connection so finally when tanks are almost  completely empty we drain them out the bottom.   Fill with fresh fuel and no trouble ever again.   Is there a pickup screen in the tank plugging and it would clean itself when engine is off?  That was our thoughts and maybe yours.  

Had the same truck with the 9 speed.  Went real well.  More power than the old 350s.   We pulled 100,000 lbs with it and highway was no problem.  Did 75mph so was geared pretty high.   I wouldn't be scared to use it on anything you use.  Our 140,000 lb super b's we used the 427s on but some people used the 350's.  too much for them in my opinion.

2016 chu 505hp

our 2013 only gets 35psi

I see those instructions on our sunvisor. Wondered if yours did

2016 rawhide.  Similar symptoms as yours but when mine wouldn't shift you could hear an air leak as well from inside the bell housing.  Thats where the shift valve is.  Had to get trans removed, valve replaced and did clutch at the same time. Also got software upgrade for trans. Software upgrade was a lot nicer so we took our 2013 in for the update as well and it sure shifts nicer and at better times.  Our lightning bolt would come on when it wouldn't shift and sometimes I had to restart it several times to get going.  Once it was warmed up it was better but not perfect

Had a 97 mack that would only push a/f on big load and it was a crack in the head and the turbo was pressurizing the system.  We got the head checked for cracks and  found it

I had same issue,  put in power divider and it went away.  worn peanuts.  

Love the truck, is that a dog or a sheep under the tent?

The mp8 is right above the water filter, not sure if the mp7 is too but looks similar.  Its in an Aluminum piece on the mp8, not the actual block.

The rpm/mph gauge on ours stay on all the time regardless of light switch.  So guessing light switch or relay is bad or breaker is tripping for that section of lights

All our 97 ch have them. They’re electronic engines.   The solenoid will be on the passenger side inside the frame rail behind front tire.   On our Jake switch, 1 was both heads and position 2 was both heads and butterfly.   Worked better than nothing but not great.    

A stored a code P2698 in your diesel powered vehicle means that the powertrain control module (PCM) has detected improper voltage that is outside the normal expected value range within the fuel injector control circuit for the exhaust aftertreatment system.

https://repairpal.com/obd-ii-code-p2698-exhaust-aftertreatment-fuel-injector-a-performance

26 was all we got for boost with ours. Best money spent was rebuild pump and injectors, seemed to smarten ours up. 

I need to follow this as well, 2013 i bought this year, 3 hours into first trip I had the same thing but was 45 minutes from home and it gave me 60 minutes.  Did a regen and have never had the issue again.  My 2016 has a soot gauge which is nice to see so you can tell if it needs a regen soon. We're all short hauls so tough to get a good burn some days.

Where is this speed sensor and how did that let you limp home? Did it give you your speed back?

Our 2013 and 2016 Mack CHU have bulbs for headlights, 9004.   When we update them to LED they will flash on and off inconsistently due to the module not getting enough current.   Found this on Amazon.ca that goes in series that fixes the problem and draws extra current https://www.amazon.ca/gp/product/B081Q6W3LR/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I'm not sure how to do the picture of it or if the link will work right from canada

The power also goes through the signal light switch.   Try signalling as well or play with that switch to see if that changes anything.   The parking brake lite and the applied brake light are 2 different air switches. One is pressure on , the other is pressure off.

Someone else replied to your post but it was removed as it was a scam

That email address comes up with a parts scam in the UK

That email address comes up with a parts scam in the UK

In 2000 they started putting cab filters in, before that you could get the aftermarket cowl filters that sat in front of the windshield

https://www.raneystruckparts.com/mack-Cab-air-filter-ch-cv-cx-cl/

https://www.truckid.com/mack-pinnacle-series-cabin-air-filters/

AS far as I know there isn't one.   If you are getting poor air flow it usually plugs up with dust and chaff next to the evaporator inside the cab.  You can remove front panel and pull fan out and blow it back or we quite often remove the screws from the black cover on the passenger side next to the blower fan and can get enough room to clean it out there.   Grain dust fills it nicely.  We have foam screens over the vents outside but they aren't perfect either.

Do you happen to know what the vehicle is?