CmLandWorx Posted Monday at 08:49 PM Share Posted Monday at 08:49 PM I have an 07 granite CTP 713 dump truck with the MP7 motor and a mack manual trans. About two weeks ago when returning from running all day the truck derated. When checking the codes they were all random low voltage electrical codes for different sensors in the 5v sensor system. I fix about a dozen or more chaffed or damaged areas in the harness. My intake manifold gauge isn't working, as well as my exhaust temp gauge. I replaced the intake manifold gauge, and it did not fix the issue. The only code I am getting now is a generic low voltage code for the entire 5v system. I have checked the voltage at most of the sensors in the system and it is at 5v. One or two of the sensors were only getting around 4.7v. The truck ran ok for about 8 hours last Thursday and has since derated again. Looking for the wiring diagram for the truck if anybody has it or any ideas on next steps to take to attempt to get the truck back working. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/ Share on other sites More sharing options...
Joey Mack Posted Monday at 10:49 PM Share Posted Monday at 10:49 PM Have you unplugged the EECU to see if oil has wicked its way through wires ? I am not sure if that model had the same wicking issues as the '07 emissions MP-7's. There was a buletin on it Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575167 Share on other sites More sharing options...
CmLandWorx Posted yesterday at 11:45 AM Author Share Posted yesterday at 11:45 AM 12 hours ago, Joey Mack said: Have you unplugged the EECU to see if oil has wicked its way through wires ? I am not sure if that model had the same wicking issues as the '07 emissions MP-7's. There was a buletin on it I have an there was oil in plug A and I cleaned it out as well as a good bit of the wiring harness leading to it Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575196 Share on other sites More sharing options...
terry Posted yesterday at 12:25 PM Share Posted yesterday at 12:25 PM Looks like you found the problem. Terry Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575198 Share on other sites More sharing options...
CmLandWorx Posted yesterday at 12:47 PM Author Share Posted yesterday at 12:47 PM 21 minutes ago, terry said: Looks like you found the problem. Terry No it still is having the same problem after cleaning the oil out. I did that 2 days ago. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575200 Share on other sites More sharing options...
terry Posted yesterday at 02:31 PM Share Posted yesterday at 02:31 PM If you had oil in the harness , did you replace it? terry Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575209 Share on other sites More sharing options...
CmLandWorx Posted yesterday at 02:49 PM Author Share Posted yesterday at 02:49 PM 16 minutes ago, terry said: If you had oil in the harness , did you replace it? terry No I cleaned the plug and wires going back into the harness, when checking I have power moving through the wires going from the boost sensor to the ecm plug on all wires. could it be on the wire that goes from the ecm to the dash cluster? Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575212 Share on other sites More sharing options...
The Heinz Posted yesterday at 03:05 PM Share Posted yesterday at 03:05 PM There's an FSB out there about using an anti-wicking pigtail to keep oil from entering the harness from the oil level/temp sensor in the pan. The bulletin states you shouldn't need to re place the harness, but that depends on if there was any damage caused by the oil intrusion. Here's that bulletin; the pigtail kit is available. MACK-PV729-FSB284-047-M.pdf 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575213 Share on other sites More sharing options...
The Heinz Posted yesterday at 04:30 PM Share Posted yesterday at 04:30 PM I do want to clarify, that will only help if the harness is taking on oil from the oil pan plug, we've seen the same problem up at the valve cover where the injector harness plug is. Our solution as a dealer was to replace the whole harness in that case, due to the amount of oil that contaminated it. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575221 Share on other sites More sharing options...
Joey Mack Posted yesterday at 04:51 PM Share Posted yesterday at 04:51 PM And i think the oil pressure sensors do it too... Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575224 Share on other sites More sharing options...
CmLandWorx Posted yesterday at 04:55 PM Author Share Posted yesterday at 04:55 PM How hard is it to pull the wiring harness out? Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575225 Share on other sites More sharing options...
Joey Mack Posted yesterday at 05:20 PM Share Posted yesterday at 05:20 PM Well........ For one, you will need to pull all the plastic panels around the steering column, pedals, doghouse covers and passenger side kick panel to get to the rear engine cover. There are 3 sensors on the back of the engine, if you have an EGR valve. These plugs are the same, so mixing them up is easy.. Mark them and really all of them, ive done a dozen on MP -8's and a few MP-7's... So i expect you to finish on day 2. The valve cover comes off too. I assume yours is a 2004 emissions engine, Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575230 Share on other sites More sharing options...
Mark T Posted 22 hours ago Share Posted 22 hours ago Wiring harness and that's assuming nothing managed to wick it's way into the ECM. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575242 Share on other sites More sharing options...
CmLandWorx Posted 17 hours ago Author Share Posted 17 hours ago So I got the harness out, it’s soaked in oil from where it passes through the valve cover, called my local mack dealer and they said it is on national back order, also can’t find it online any where. Would cleaning the entire harness and putting new loom and tape on it (essentially rebuilding it) be a viable option or do I need a new harness? Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575279 Share on other sites More sharing options...
Joey Mack Posted 17 hours ago Share Posted 17 hours ago No it wont, the oil is pulled through the wire itself. The posts in the sensors have open tips, and oil was pushed through the sensor by oil pressure, and the flow of the electricity picks up the oil and carries it inside the wire strands. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575280 Share on other sites More sharing options...
Mark T Posted 17 hours ago Share Posted 17 hours ago I can't picture any part of it under the valve cover living through being touched. Guy I know just bought one a couple months ago. Maybe he was just lucky ??? Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575283 Share on other sites More sharing options...
CmLandWorx Posted 17 hours ago Author Share Posted 17 hours ago Understood, does anybody have a line on a new harness? Only one I can find only is from buyparts.online and I’m skeptical of the site. Mack said that it was a national back order and it did not give any type of estimated in stock time frame. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575284 Share on other sites More sharing options...
CmLandWorx Posted 17 hours ago Author Share Posted 17 hours ago 3 minutes ago, Mark T said: I can't picture any part of it under the valve cover living through being touched. Guy I know just bought one a couple months ago. Maybe he was just lucky ??? Honestly the section under the valve cover looked and felt better than most of the rest of it. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575285 Share on other sites More sharing options...
Mark T Posted 17 hours ago Share Posted 17 hours ago There's a fella on the site here called The Heinz. He's pretty gracious about helping out confirming things like that. Maybe he'll chime in on that. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575286 Share on other sites More sharing options...
Mark T Posted 17 hours ago Share Posted 17 hours ago Usually under the valve cover, the insulation falls off it as soon as you touch it after a few years. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575287 Share on other sites More sharing options...
Mark T Posted 16 hours ago Share Posted 16 hours ago Usually under the valve cover, the insulation falls off it as soon as you touch it after a few years. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575288 Share on other sites More sharing options...
Mark T Posted 16 hours ago Share Posted 16 hours ago The plug where the engine harness plugs into the chassis harness on the left side down like by the spring hanger is another popular spot for issues. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575289 Share on other sites More sharing options...
CmLandWorx Posted 16 hours ago Author Share Posted 16 hours ago 15 minutes ago, Mark T said: The plug where the engine harness plugs into the chassis harness on the left side down like by the spring hanger is another popular spot for issues. That had oil in it as well. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575292 Share on other sites More sharing options...
Mark T Posted 16 hours ago Share Posted 16 hours ago Not sure about where you live, but up here the green stuff wicks into there too. Gotta look close there , do the ten pound test . New harness won't make much of a difference if that's bad there too. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575293 Share on other sites More sharing options...
CmLandWorx Posted 16 hours ago Author Share Posted 16 hours ago 24 minutes ago, Mark T said: Not sure about where you live, but up here the green stuff wicks into there too. Gotta look close there , do the ten pound test . New harness won't make much of a difference if that's bad there too. What green stuff are you referring to? And other than a little oil on inside of the connector that harness looks good other than road grime and grease on the outside. Quote Link to comment https://www.bigmacktrucks.com/topic/75490-07-granite-ctp-713-electrical-issue/#findComment-575297 Share on other sites More sharing options...
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