Perkins Diesel Engine Review - ElectroPak Model 404c-22g
aka: HP35105U, 5H3XL2-22 NLC, HP29-1800C
Wiring required to get it running
by Joe Mehaffey
rev 10/1/2012 Release 5

I received a Perkins 404c-22g diesel engine from Hardy Diesel to replace my old worn out (200 hours of service) ChangChai Chinese built diesel engine.  Yes.. I know.. 200 hours life for ANY diesel engine is unheard of.  But.. For the ChangChai SAGA, click HERE.  After getting it connected to my MECC-ALTE EC0-28-L2 (21KW prime, 24KW standby) alternator, I can say that the two engines are as different in sound and performance as a hammer drill is to a sewing machine!  The Perkins is MUCH quieter, and though it too is far from "silent",  it does not sound like it is going to shake itself apart.   The 29HP (at 1800RPM) engine is a much better match to the MECC-ALTE EC0-28-L2 alternator than was the ChangChai. I bought the oversize alternator when the original DADI alternator failed on the ChangChai system several years ago. 

I will note here that as of October 2012, my Perkins Engine has performed flawlessly now for about 6 years requring only routine oil change and checks.  No faults of any kind. 

The Perkins engine came to me in 2006 with no documentation whatsoever.  While the mechanical connection of the alternator and engine was fairly straightforward,  I had considerable problems getting even basic information on component electrical connections for the engine.  How our Perkins friends expect anyone to properly wire the engine controls without Perkins providing even basic information on what the connections are and how they function is beyond me.    If anyone has any additional  information, let me know and I will add such to the list below.  NOTE:  As of September 2012, I have been furnished a complete Perkins Wiring Diagram for the Perkins Engine connected to the DynaGen GTC300 automatic engine controller.  This Diagram is added at the END of this page.

For wiring, be sure to use #16 or 18 wire (except as noted otherwise)  for all connections to minimize voltage drops in the wire and insure the ability to start the engine under less than optimum battery conditions.  The wiring from the glow plug relay to the glow plugs should be #12 or #14  wire.  The wire from the battery post (or from the battery connection on the starter solenoid) should be #10 or #12 gauge.   Use proper through hole (not spade) lugs on all screw terminals for maximum reliability.

1) The Engine  has a 12vdc fuel control solenoid that must be activated for engine run and deactivated for engine stop.  This solenoid is attached to the rear of the injector pump. The pigtail connector cable out of the solenoid has a two pin connector, female socket with male pins. All three of the Perkins connectors are keyed the same so be SURE to harness them  on the engine so they cannot get interchanged.  These are the two wires to the solenoid coil.  You must ground one wire and connect the other wire to +12vdc power to energize the solenoid and allow fuel to reach the cylinders.  The wires are not polarity sensitive. See image below. In my installation, I used a common ground wire for the fuel solenoid and for the oil pressure switch and grounded the common connection.  Then the ungrounded fuel solenoid connection is powered by +12vdc for engine run.   Oil pressure switch details are in item #4 below.

2) The engine has a starter solenoid and switch mounted on top of the starter motor as is conventional.  At first glance, you will see only two terminals on the starter solenoid.  The first goes to the starter motor and the second is to be connected to the battery.  A third "slide on" terminal is semi-hidden behind the starter solenoid.  This "tongue" terminal is to be connected to a female slide on socket (furnished in the parts kit) and is to be connected to the "crank" terminal on the ignition switch or engine controller.  See Image below.

3) This engine is equipped with a glow plug starting system, one glow plug for each cylinder. The glow plugs are mounted vertically and are located  just above and behind the four fuel injectors.  A sheet metal interconnection bar joins the four glow plug power terminals.   The attachment point for the glow plug power wire is on the left end of the  stamped sheet metal connecting bar.    It is best to feed this glow plug system with #12 or #14 wire as the buss draws about 15 amps DC.  Normally you turn on the glow plugs for about 7 seconds before cranking to allow the glow plugs to assist in starting.  To maximize power available for the starter, the glow plug power is normally turned off immediately before cranking is commenced.  It is not normally  necessary (but it is OK)  to use the glow plugs above about 60F.  I note that my engine will not start at 40F and lower without the use of the glow plugs.

4) The engine oil pressure and temperature sensors are SWITCHES and not analog sensors.  The switches CLOSE on out of tolerance conditions.  The temp switch closes at about 205 degrees F signaling engine overheat and the oil pressure switch closes on low oil pressure. Both switches are two terminal SPST  isolated switches  with Perkin's unique two pin connector.  The oil pressure switch is closed when the engine is stopped and the water temperature switch is open when the temperature is below 205F.   It is intended that these signals be interconnected with a suitable relay or other circuit to shut off the fuel solenoid should the engine have either low oil pressure or an overtemperature condition.  See the  image below for the location of the WATER TEMPERATURE switch and the image in item #1 above for the location of the OIL PRESSURE switch.

5) Connector pins and fittings for Perkins two pin connectors are furnished in the kit with the ignition switch, air heater and other fittings.  These pins are designed to be crimped onto  #16 to #18 gauge wire but you can solder them onto the wires (carefully with a 47 watt iron) if you do not have the proper crimp tool. if you solder, you must be careful not to get solder on the outside of the pin body, else the pin may not fit properly in the connector body.  Use of a crimp tool that FLATTENS the connector pins is NOT advised as it can prevent the connector pin from entering the connector body and seating properly.  The proper crimp tool is a "mil-spec" tool that crimps the pin on all four sides in the area where the wire enters the pin.

6)  The 12 volt automotive generator supplied with this machine is a six terminal unit but only TWO terminals are used.  The FIELD winding(A) and OUTPUT terminal(E) are the only terminals used and are shown in the image below.   The OUTPUT terminal(E) is the screw/nut terminal located nearest the engine core.  The FIELD terminal(A) is the topmost slide on connection terminal.  See picture below for locations.  The mating "slide on" female connector is furnished as part of the hardware kit along with the ignition switch assembly.  Slide on connector pins can also be found at any automobile parts store.  Pins B, C, D, and F are not used.

7) A suitable wiring diagram for the MANUAL ignition switch( furnished with the kit is shown below.  This is a four position switch.  The positions starting from left are HEAT, OFF, RUN, and spring return START position.  Basically, the switch is wired so that when the switch is turned to the LEFT, the glow plug heat is turned ON.  Then when you turn the switch to the far right both the generator fuel solenoid and and the starter solenoid are engergized.  Then when you release the key, the key springs back counterclockwise to the RIN position.  The Starter Solenoid is energized in the START position.  Note that with this manual switch system, if you leave the switch in the LEFT (HEAT) position for a long time you will probably burn out your glow plugs plus you will definitely run down your battery.  If you leave the switch in the RUN position with the engine stopped,  you will also eventually run down your battery.  For these reasons, you will be a lot better off to have some automatic start/run/stop system which will automatically start and  stop your engine and not accidently leave the system in a state to run down the battery.  Two such appliances are described below in item #8..

(Drawing in Work showing manual ignition switch setup)

8) Automatic Engine Starters suitable for use with the Perkins 404c-22g ElectroPak engine (and similar small diesel and gasoline engines) are the DynaGen GSC300 and GSC400 controllers and the FW Murphy ASM-170 and Cascade models.  The GSC300 model is sold direct by DynaGen/Canada  for about US$190 plus shipping.  A wiring diagram to connect the GSC300 model to the Perkins ElectroPak is shown below.  The other controllers are wired similarly.  Controller setup involves selection of such parameters as start motor run time, restart holdoff time,  glow plug operate time before start,  run time after switch off signal, and other parameters depending on controller model.

(Drawings in Work for GSC300)

9)  The item below looks like some sort of inlet air heater, but I cannot figure out (yet) where to put it. I assume it is supposed to be energized at the same time as the glow plugs.. When I find out more about it, I will add details here.

10) If desired,  tapped holes are available on the engine for separate analog water temperature and oil pressure sensor installation.  You can purchase such auxiliary sensors from almost any automobile parts store.

Below is a picture of the overall engine/generator system with the enclosure side panels removed.

PS> CellPhone cameras are not superb, but for something like this, they get the job done quick and easy.

  Wiring Diagram for DynaGen GSC300 to Perkins Diesel Engine as of September 2012
The original PDF document can be seen HERE.