My Pete rebuild

[Nostalgic]

(03-19-2021 )Lonestar10 Wrote:  i would tie a light onto the fan solenoid and see if the trucks actually turning it on before that unless you got something from the scrap yard but i cant see it being a pete even a lousy hvac control costing less than 500 bucks vs a most likley free light if ya got stuff sitting around. would also look into possibly the solenoid to turn the fan on dieing or the high pressure switch on AC.


also with rag issue maybe something near the engine temp sensor causing spikes?

It stays on for a minimum of 10 or 15 seconds. I'll have to hook up the computer and see what minimum time is set for a/c cycling. I thought it was 30 seconds, but I could be wrong. Another possibility is a bad coolant temp sensor. While my gauge doesn't bounce, I'm pretty sure the coolant temp from the ECM goes through the CECU to the gauge and it could "buffer" spikes. I've noticed it does it mostly while accelerating, so I guess intake temp sensor could possibly cause it too (put a new one on 15-20k ago, but that doesn't mean anything). Lots of "could be's" on this one...

[Lonestar10]

yeah cant trust a damn thing from cummins nowadays on my lonestar i got 1 bad fuel timing solenoid and 1 bad metering solenoid right out of the box, had 2 of 6 injectors blowing air bubbles right out of the box, when i replaced ECM first 2 they tried were the ones that got recalled of course 1 accepted their programming then died before i made it out of the lot 2nd one off the shelf they couldnt even get to program 3rd one i had to wait a week to get.

let alone i had the mechanic at cummins tell me one night he had to put 4 or 5 different turbos on a truck before one worked right. those mexican parts sure making them bank at our expense.

[Chamberpains]

Set your laptop up so all you have to do is reach over and slap the space bar to start recording on Insite.

Turn the screen brightness down to minimum or even tape something over it to keep from blinding or distracting you.

Lock the screen to never sleep.

Face it in such a way that you don't have to see the screen going down the road.

When the fan starts doing whatever it does. Reach over and get it to start recording.

This is how I monitored, captured and was able to track down a TPS wires that were bad and causing very random throttle issues. It took a week or so of capturing data from sensors to narrow it down to TPS signal voltage flickering 0.1v rapidly when it was doing its thing that got me to rip the braided TPS wires out and replace them end to end. Sure enough they were just rubbed enough everywhere to cause the issue and replacing them fixed my problem.

[Nostalgic]

I dug around, and while I can't do much with ESA, I'm pretty much convinced it's a multiplex issue. I'm not sure how to command fan at 50%, or how that works exactly? What's it do, 6 volts to the clutch solenoid? Nothing at all in abuse history to suggest that it was reading high intake manifold temps, coolant, or other, even for a second.

When I called in to get the HVAC control (It's my first choice because mine is physically broken and falling apart), my pretty good parts guy at Hunter's said CECU. Something along the lines of "Our CECU's are pretty much junk, and we replace a lot of them". Mine's been flakey from day one, but usually a key off cycle or battery disconnect reset "cures" it's fits. I did load up a logger page to do what you mentioned @Champerpains, so we'll see how it acts this week.

Either way, I'm probably going to plan on replacing the CECU, my Start/Charge harness, and possibly a new engine harness. We're 14 years old and it's time anyway.

[Rawze]

(03-20-2021 )Nostalgic Wrote:  ...
not sure how to command fan at 50%, or how that works exactly?
...

that option only works if you have an electric, variable speed fan clutch. If yours is air-driven, this is not an option.

[JimT]

could still be a/c pressure causing the fan to come on. Mine did that randomly a week ago while parked. 30 degree outside temps and the entire HVAC system wasn't even on.

Also, like Rawse was saying, if your's is air operated then air pressure and leaks should be on you list of things to check out.

[Nostalgic]

Well, after 2 weeks of it driving me crazy, I set up the laptop to have on hand and with the cables all at war with my ocd I went to work for the week. Nothing. Not a single funky fan engagement all week lol. Just figured I'd give an update even without a diagnosis.

That said, I'm trying to enjoy the current name-your-price market while it lasts.

[Chamberpains]

You've been noticing that with freight too? Grab it while you can. If it's short lived then you got some while its here. If it's a true economy busting at the seams to get going then you're in front of a massive year and ride it comfortably and enjoy what I assume is much needed relaxing and efforts put else where... and so goes the life of a good O/O truck driver.

As far as the A/C deal. Did you have to unplug anything on the truck to hook up Insite for monitoring? ELD? Maybe you unplugged something that is causing interference and making the cab controller glitch.

Also, monitor closely sensor voltages. Like the A/C high pressure switch, the fan solenoid oil temp sensor, coolant temp sensor maybe even the jake on/off switch (the ecm could be thinking the jakes have been engaged for 30 seconds and demanding the fan on) and anything else related to turning the fan on. All it takes is one of these sensors to flicker for whatever reason and the fan comes on for an alloted amount of time.

Other than that, can you use ESA to monitor what the CECU is demanding on the system. I never got a chance to use that program so I'm just guessing what it might be able to show you.

[Nostalgic]

(03-27-2021 )Chamberpains Wrote:  You've been noticing that with freight too? Grab it while you can. If it's short lived then you got some while its here. If it's a true economy busting at the seams to get going then you're in front of a massive year and ride it comfortably and enjoy what I assume is much needed relaxing and efforts put else where... and so goes the life of a good O/O truck driver.

My fear is $5 fuel and the bottom dropping out of the market with $1 freight posted that gets covered immediately. Doesn't matter much, old Joey and the agenda is destroying the dollar as fast as possible anyway.

(03-27-2021 )Chamberpains Wrote:  As far as the A/C deal. Did you have to unplug anything on the truck to hook up Insite for monitoring? ELD? Maybe you unplugged something that is causing interference and making the cab controller glitch.

The only thing I did was disconnect and spray some amsoil metal protectant on the plugs for the high pressure switch @ the compressor and the fan control solenoid. Was it possible the contacts were bad? Or a funky corroded or broken wire made a connection after disturbing the harness? Either could be true, which is why (if the economy supports my trucking endeavors in the near future) I plan on replacing most of the external wiring harnesses regardless.

(03-27-2021 )Chamberpains Wrote:  Other than that, can you use ESA to monitor what the CECU is demanding on the system. I never got a chance to use that program so I'm just guessing what it might be able to show you.

ESA is very limited on what it can do. 99% of it's functional ability is gauges. You can test the gauge, and turn them on and off, or monitor the gauge data and change the backlight and brightness on the info panel (I finally changed the economy meter display to not encourage driving @ 1200 rpm lol).

But the limitations are annoying. I found a chime sound in ESA called tinkerbell that I wanted to use for my trailer dump valve. Not annoying, but something to remind me it's on. I dug through the harness in the dash and tested all of the "alarm" inputs, but none were for my tinkerbell sound, and I haven't found a way to reassign a sound to an input.