STROKER_T Posted July 8, 2009 Share Posted July 8, 2009 Good morning,was wondering if i could get some direction... Got an 07 F750 no crank,the (allison) push button gear selector is showing cat eyes,which i gather is a communication problem.I've checked the fuses at the batteries,and the harness that runs below the bell housing looks ok. I've got it narrowed down to either the push button selctor or trans module,but as you've probably already guessed,this is NOT my forte'...the truck is used for heavy equipment repair,so yes,they are wanting it fixed yesterday. I was hoping there may be some allison experts that could help.Guy said he was drving down the road,truck jumped gears,stalled,and hasn't started since.I can start it only by jumping the starter,so I'm sure it's a trans issue,limited resources (and training) on this...any help would be awesome,the experience should do me good. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted July 8, 2009 Share Posted July 8, 2009 Stalled? This makes me concerned. I'd hook up Insite (it's a Cummins, right?) and see what's going on with the engine. Do you have Allison Doc? It has great diagnostic charts in it. I'm no Allison expert by any means, but we (Anthony) do teach an Allison class. I'd start with making sure the tranny is getting clean power to the ECU, which means unplugging it, identifying the powers and grounds, and loading them appropriately depending on wire gauge and fuse rating. In IH trucks, more than half of the Allison problems are in the IH harness, so I'd guess that Fords are the same way. Look for harness rubs, tugged harnesses (IH is notorious for this), corrosion or moisture in the connectors, interference from two-way radios or high amperage circuits running nearby. Good Luck! Quote Link to comment Share on other sites More sharing options...
STROKER_T Posted July 8, 2009 Author Share Posted July 8, 2009 Thanks Bruce...wanted to mention that we do not have allison doc,not even sure if we have the data connector to check for codes,there's a ford dlc and a round one under the dash,couldnt tell ya which i'm supposed to hook up to for trans codes recieved. Was wrong about it stalling,i asked the driver,said he pulled over when it changes gears abruptly,the stop engine engine&check trans lights came on,also noticed the cat eyes on selector display,he turned it off and a no crank after that. It's got a cummins engine,allison trans,neither of which do i ever work on...so i gotta bite the bullet on this one...gonna check the harness again,maybe something will jump out at me. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted July 8, 2009 Share Posted July 8, 2009 IIRC, on a F750 the 16 pin OBD2 connector is for heater or dashboard info. The round 9 pin Deutsch is where you'll access engine and tranny info. You're really batting blind without software here and I don't know what else to tell you. What trans is it? 1K/2K, or World? 1K/2K have a sheet metal pan and spin-on filter, Worlds have aluminum sump (control module) with filter caps in the bottom of the "pan". There's a lot of free info on the Allison website, but maybe not what you need. If you give me a model number (1000, 2000, 2400, MD3060, etc) I may be able to help you out a bit more, but I'll be away from my PC for the next several hours. Good Luck! Quote Link to comment Share on other sites More sharing options...
Damon Posted July 8, 2009 Share Posted July 8, 2009 It sounds like a pushbutton keypad issue. That'll cause the no start since it has no way to know if it's in neutral. The Deutsch is for the engine and trans. Quote Link to comment Share on other sites More sharing options...
STROKER_T Posted July 8, 2009 Author Share Posted July 8, 2009 Somewhat good news here...went over the harness again,ck'd for corrosion,ect....found 2 wire connector just below bell housing backed off a bit,secured connectors with tie straps and wa-la,the bitch fired right up! Explained to the customer what i did word for word,he fixes diesels everyday,just a different variety,he's happy,i just hope it gives him no more problems.I hate to let a truck go without absolutely knowing the cause for the concern,but when it comes to something like this,what can you do? I jokingly gave him the lightpole warranty... Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted July 8, 2009 Share Posted July 8, 2009 I've sold quite a few vehicles with a "taillight" warranty. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted July 9, 2009 Share Posted July 9, 2009 2 wire connector? 10 ga red and white wires? If so, this is a huge pattern failure on IH chassis, and an F-750 is an IH chassis..... PS Duh- I don't think cat-eyes shifters are available on 1K/2K trannies. Upon thinking more, if it goes cateyes it has to be a WTEC. I've got a nice shifter diag PDF I'll send you if you e-mail me. (Keith, will we ever be able to post PDF's here?) Quote Link to comment Share on other sites More sharing options...
STROKER_T Posted July 9, 2009 Author Share Posted July 9, 2009 Yeah Bruce,10 gauge,thanks again for your help.What you do for this website is great,really appreciated...the truck hasn't skipped a beat since it left,the owner has my service managers cell #,so if it does act up,I'll definetly hear about it,it's one of them deals... Turned out to be a simple loose connector issue that I should've caught on the preliminary inspection...another lesson learned,I guess.It was so close to being towed to an Allison dealer...the harness is routed really tight on these,not much give,betting this kinda thing happens alot, although I probably wont see another F750 for 6 months or more,its mostly F250 -550's here...gotta love it Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted July 9, 2009 Share Posted July 9, 2009 the harness is routed really tight on these,not much give,betting this kinda thing happens alot These trucks can get pretty hairy when it comes to diagnosing anything that uses shared data and I was hoping you would find something simple. I had some early 2007 F750's that had harness issues. Getting help from CAT was easy, Ford had no information and Allison would not even talk to us because we are not an Allison service center. Harnesses? Tight? I changed 5 harnesses in affected trucks. They are not only tight but they use an obscene number of zip ties to secure them. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted July 9, 2009 Share Posted July 9, 2009 Keith, will we ever be able to post PDF's here? Yes! The file attachment issue was fixed last week and tested. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted July 10, 2009 Share Posted July 10, 2009 Hey Guys: Now that Keith has successfully led me through the (not) intricate process of posting a PDF, I have uploaded an Allison Shifter Diagnostics PDF for World trannies. Have fun! Quote Link to comment Share on other sites More sharing options...
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