FLD120 no start, no cab gauges

Discussion in 'Freightliner Forum' started by cfannin1, Sep 10, 2015.

  1. cfannin1

    cfannin1 Bobtail Member

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    Sep 19, 2013
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    99 FLD 120 with 60 series detroit. Parked up Monday and did the walk around. All was great. Tuesday morning, no gauges, no start. It will turn over but not crank. I have checked the following: hot and ground leaving battery, including in line fuse; power plug to ECM ground and positive are good; data link - and + in vehicle harness; switch key run and crank mode are good; physically exchanged ECM and EDM with no results; cleaned and inspected all grounds to motor and frame; tested ground and hot for breakers and relays in the cab panel. I have no clue where to go from here. What the heck powers everything in the cab and can keep the truck from starting? It's like I'm missing a relay/breaker/solonoid or something that I'm not finding. Any help appreciated.
     
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  3. GrapeApe

    GrapeApe Road Train Member

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    The main fuse panel gets power from the positive post of the starter. In the fuse panel there is a row of relays on the right that get power with the key. I don't remember which one, but you have a ignition relay that powers all of those.

    What exactly to you mean when you say it will turn over but not crank?
     
  4. cfannin1

    cfannin1 Bobtail Member

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    Sep 19, 2013
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    I have power to the key and it will engage the starter and roll the engine over but it will not crank. I can do that all day until the batteries go dead but it won't crank. And I'm guessing that whatever has killed power to my cab also won't allow the truck to start. I have changed out ignition relay, starter relay, "??" power shutoff relay, actually all of the relays in that row with no luck.
     
  5. mgrantes

    mgrantes Light Load Member

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    Unsure if yours operates the same way, but recently while diagnosing and changing out my starter I noticed that once I disconnected all my battery cables (well, anything leading to truck electrical) and connected them again, my all my interior lights wouldn't function until I started the vehicle. Once started, everything else would come alive and behave normally. Also, have you tested and ruled out the starter? You said that it cranks, but how strong is the cranking? If it's good, then it could be a fuel check valve or leak in the line. I've read a few threads that points to the check valve being the culprit. I'm also assuming that you see both yellow and red check engine lights when you turn the key to acc position? If so, then your ecm should be fine.
     
  6. cfannin1

    cfannin1 Bobtail Member

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    Sep 19, 2013
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    As stated, there is NOTHING active in the cab except the radio and the cig lighter plug and those are direct connect. No buzzer, no warning lights, no gauges, a/c, fan, nothing. The gauges don't even do the normal sweep prior to cranking. And I have 4 hot batteries on the truck, one bought just for this reason. So my assumption is that whatever is killing power to the cab is also killing power somewhere and not letting the truck start.I have fire at the ECM, even using a borrowed one, but no start. None of the electrical, including battery cable, were disconnected prior to this happening. We simply hooked back up to our trailer, did a trip inspection and parked up the night before. Same as always.
     
  7. GrapeApe

    GrapeApe Road Train Member

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    So it is cranking, but not starting, that's where I was confused. Cranking means that the starter is turning the engine over. So you're engine cranks, but will not start. Your power issue is probably not powering up the ignition wire to the ECM.

    You should have a relay in fuse panel labeled "Ignition". Does that relay click when you turn the key on? You can temporarily jump the relay to see if that's your issue. Jump the 30 to the 87 terminal to jump the relay.
     
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  8. mgrantes

    mgrantes Light Load Member

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    Hmm that is weird. (Thanks for the clarification). Have you also checked your secondary fuse panel? I don't know much about it, but I can't think of anything else right now. The secondary panel is usually located at either the dirivers or passengers side pillar right behind the seat. I've read a few threads about water finding it's way inside there and corroding stuff. Again, unsure what kind of problems are associated with corrosion in that area. Still, it's an easy enough check for sh$tz and giggles. ;)
     
  9. cfannin1

    cfannin1 Bobtail Member

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    Sep 19, 2013
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    I have had the truck, and other FL's, and this year model doesn't have another fuse panel. Just the one beneath the radio with relays and circuit breakers. If there are any somewhere else, I've never seen or found them. @GrapeApe I've never heard the relay click, but I called myself checking it in addition to putting a brand new relay in there. I would figure that the relay "holder" could also be shorted across inside possibly. But I'm just puzzled as to why I lost both starting/running and cab power simultaneously. The only relays I have not checked are the 4 located on the very top left in the panel. They are up high and I can't see or read any of the labels on them, if they are still legible.
     
  10. cfannin1

    cfannin1 Bobtail Member

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    Sep 19, 2013
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    I thought about checking the main harness where it comes into the panel, but it's probably pointless as I have both power and ground going to everything. I'm guessing that I need to find where it goes "out" to motor or ECM maybe
     
  11. GrapeApe

    GrapeApe Road Train Member

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    Even if the relay is good, if it doesn't have power or ground to activate it, it wont work, which is why a said to try and jump it. Everything that gets key on power comes through that relay, so that's where I'd focus. You said you have good power and ground to the ECM, so I'm guessing that the ignition power is not making it to the ECM to turn it on. That comes from the ignition relay, which also powers all the other ignition on circuits.

    On the ignition relay, you should have power on the 30 terminal. 85 and 86 are the coil to activate the relay, so one should have power and the other ground with the key on. The 87 terminal powers all the ignition circuits and relays.
     
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