Discussion:
C 28 fault

When you turn on the key switch c 28 fault turn on before you try to even travel or lift. The unit does not travel or lift or even honk the horn. Battery volatge was low at 24 volts. I charged it for a hour just enough to test components. I have 25.5 volts to one side of the line contact and 24.4 at the other end. Checked fuses, relay, master switch and key switch all at 24.4 volts. Line contact does not activate I assuming because of fault code. Im getting 24 volts to my handle controller. Any help would be great.
  • Posted 31 Dec 2014 12:54
  • By crown619
  • joined 28 Aug'14 - 26 messages
  • California, United States
Showing items 1 - 20 of 26 results.
Hey there, I 'm putting a 102t f45l back together, would you have wiring diagram.or a Pdf for these ?
  • Posted 11 Mar 2025 05:46
  • By Falcon_Trothrim
  • joined 9 Mar'25 - 2 messages
  • Saskatchewan, Canada
Falcon
The c-28 code came on for me. I checked what others were saying but i found out that the Lift Pump itself had welded something inside. I hit it with a hammer and it started right back up. Replaced the lift pump. No more c-28 code.
  • Posted 25 Jun 2024 01:48
  • By xXForkliftXx
  • joined 14 Feb'23 - 2 messages
  • Wisconsin, United States
Fork a Lifter
What and where is the power amp?
  • Posted 30 Apr 2022 06:47
  • By Bill_Menchen
  • joined 26 Mar'21 - 21 messages
  • Nevada, United States
Bill Menchen
Welded contacts and burned components are an indication of a weak battery. Weak battery can generate c28.
  • Posted 19 Sep 2017 05:39
  • By stam
  • joined 12 Aug'12 - 779 messages
  • Ontario, Canada
I have had the c28 code on a pallet, I already tried the help of raymond faults and I could not repair the fault, the pump contactor was soldered and r1 was heated, but that has already been repaired and still shows that code.
any ideas??
  • Posted 19 Sep 2017 03:36
  • By carlos_h
  • joined 19 Sep'17 - 1 message
  • Chihuahua, Mexico
Change lift contactor
  • Posted 6 Feb 2016 07:18
  • By terrance_g
  • joined 25 Sep'14 - 1 message
  • Texas, United States
recently had a C-28 on customers jack. checked all the normal reasons(switch off, fuse blown, bad fuse holder). found welded lift pump contactor cause of code. high current draw causes motor controller to shut down. if forks are stuck in fully raised position with this code, check contactor.
  • Posted 18 Sep 2015 08:13
  • By forkdoc
  • joined 20 Sep'14 - 13 messages
  • New York, United States
Usually a dead short and a hot R1 lead to no function what so ever. Sounds more like something is drawing to much current, measure current draw in series with R1 and compare to a known good truck.
  • Posted 9 Jan 2015 11:32
  • By TTLLOGIC
  • joined 25 Dec'14 - 15 messages
  • Ohio, United States
I just Left another service call for a Raymond same model with c28 found R1 hot unplugged it and ohm it out found 14 ohm plugged it back truck started up looked for any loose wire or shorts couldn't find anything.
  • Posted 8 Jan 2015 13:56
  • By crown619
  • joined 28 Aug'14 - 26 messages
  • California, United States
Congrats
  • Posted 8 Jan 2015 13:26
  • By TTLLOGIC
  • joined 25 Dec'14 - 15 messages
  • Ohio, United States
Installed new power amp resolved issue
  • Posted 6 Jan 2015 14:36
  • By crown619
  • joined 28 Aug'14 - 26 messages
  • California, United States
Measure across wires 24 and 64 at the K4 and tell me how much voltage you have across K4 coil.

Are you measuring voltage at #24 and #26? If you see battery voltage or close, then the contacts are open.
  • Posted 3 Jan 2015 11:57
  • Modified 3 Jan 2015 11:59 by poster
  • By TTLLOGIC
  • joined 25 Dec'14 - 15 messages
  • Ohio, United States
I measured k4 across Wire #24 and #26
  • Posted 3 Jan 2015 07:00
  • By crown619
  • joined 28 Aug'14 - 26 messages
  • California, United States
Main contact K10 wont close till you pull down the tiller. But if you have a C28 all truck functions are suspended, so you will not get K10 to close. K4 should be open during C28 and yes if K4 is closed K10 should be closed as well. Are you testing across contacts or measuring voltage across the relay coil to determine K4's status?

From what you just said, if the battery is falling down to 14V when powering up the unit then you probably have a bad cell or an overall tired battery pack.
  • Posted 3 Jan 2015 06:18
  • Modified 3 Jan 2015 06:24 by poster
  • By TTLLOGIC
  • joined 25 Dec'14 - 15 messages
  • Ohio, United States
That's what I really need to find out if my k4 is closed shouldn't my main contact close or does it wait for a controller for a input. The only way I load tested the battery was to turn the unit on jumped to 14v for split second which I thought was weird then to 25 volt. They have the battery case pretty welded on so I'm gonna have to get access to that to Check each individual cell.
  • Posted 3 Jan 2015 00:38
  • By crown619
  • joined 28 Aug'14 - 26 messages
  • California, United States
He has a Code 28, K10 will not close because of this condition. You will see a voltage drop across K10 due to R1, which is a pull up resistor to charge the input capacitors within the traction amplifier and to power the control functions of the amplifier. His tests indicate a normal condition.
  • Posted 2 Jan 2015 15:59
  • Modified 2 Jan 2015 16:19 by poster
  • By TTLLOGIC
  • joined 25 Dec'14 - 15 messages
  • Ohio, United States
When you said there was a one volt drop across the main contacter, stop right there. The normal voltage drop across any contacter is.1 to.3 volts. One volt is too much. Second, make sure you dont have a weak battery. Load test then all, one at a time. If you dont have a battery load tester, run the lift with voltmeter. Use min/max to test battery on start up. If there is a weak battery, voltage will drop to 17 volts. You cab only see this with min/max.
Unplug battery and check for shorts to frame. Dirty comm in drive motor or lift motor will cause issues
  • Posted 2 Jan 2015 15:11
  • By EasiTek
  • joined 12 Aug'08 - 533 messages
  • Ontario, Canada
If you have good continuity and no short between them, the only other thing you can do is monitor the CAN bus with an oscilloscope and check for noise. I think though you most likely have a bad traction amp.
  • Posted 2 Jan 2015 12:37
  • By TTLLOGIC
  • joined 25 Dec'14 - 15 messages
  • Ohio, United States
I tested can wires by ohm them out any other way to test.
  • Posted 2 Jan 2015 12:24
  • By crown619
  • joined 28 Aug'14 - 26 messages
  • California, United States
Test for short circuit and continuity.
  • Posted 2 Jan 2015 12:22
  • By TTLLOGIC
  • joined 25 Dec'14 - 15 messages
  • Ohio, United States

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