I'm having to chase a starting problem on this little piece of catalog engineering. It has a four wire engine run solenoid that harness connects to a three wire machine harness. The problem is that the solenoid will not pull in to allow the engine to run. I'm figuring the red wire is hot with the key on and the white wire goes to a relay for a safe starting system. The black wire I would think is ground. Anyone got any insight or a wiring diagram they could share. Thanks in advance. John C.
One wire is for the pull in windings the other is the hold in circuit. The third ground.
Hmm, I've not seen a 4 wire run/stop solenoid before, that's a new one on me, but on all the 3 wire solenoids I've worked with, blk is ground, red is power from ignition (hold winding), white is power from some form of time delay on/off input from either an ECM or time delay relay (pull winding).
I checked the wires with a multimeter and my white wire goes direct to ground. Sounds like it is shorted out. I didn't find any processors in this monster but there are some relays below the engine on the left side. So if I push the center shaft in manually and start the engine it should hold by itself?
Yeah, if the red wire has power from ignition and the black is ground. But then, with the 4 wire solenoid, it's a Star Trek thing for me "to boldly go where no man (me) has gone before". I'm just not sure enough of the arrangement you're working on to say anything with certainty.
I kind of like exploring with things I don't know anything about. It's fun to take things apart just to see what make them work. I'll try manually latching it when I get back to the machine. Probably be Monday now. Time to go to bed and dream of other things. Thanks for the help and suggestions.
Did some checking on the monster yesterday. The dealer was absolutely no help. The name on the solenoid was Woodward so I looked them up on the web. They had service and installation manuals that can be down loaded and printed. They explained the solenoid and gave me resistance readings. The old coil and the new one both were right on the book. So I figured my problem child was that tube which has the four wires from the solenoid going in and the three wires coming out the other end which plug into the machine harness. I'm thinking that little piece of magic is my problem. There was no explanation of that tubular monster. The manuals showed a phone number and I made the call. Left a voice mail and ten minutes later I got a call back. The gentleman on the other end was real pleasant to talk to and I think made an honest effort at solving the problem. Basically the solenoid has a pull in coil and a holding coil. It takes a lot of amps to pull the thing in and next to nothing to hold it. The red wire is the holding wire and it comes on with the key switch. The white wire is for the pull in. It is hooked to the starter between the solenoid and the starter motor. So when the starter is turning the pulling coil is getting lots of amps. Now then the pull in coil need lots of current but all those amps create a bunch of heat and threatens burning up the coil. So the piece of magic I spoke of earlier is called a "Current Commander". What the fella told me was that there is some kind of timer or heater inside that thing that shuts down amperage to the coil based on some predetermined specification. We are both thinking that extra green wire has something to do with it. My guess is that the ground side is controlled with amps being throttled back. I did turn the key on and pulled back the solenoid by hand and it still wouldn't latch. I explained to the gentleman that there was a decal on the piece of magic that said "MADE IN CHINA". I told him I had problems with "MADE IN CHINA" in the past and now thought my problem was there. He had another thought that maybe there was some kind of replacement product they sold which would work better, but some fast by my standards, computer work apparently revealed that this unit had been discontinued and there was no upgrade. I'll be back on site tomorrow so need a plan. I'm thinking of cutting out the "piece of magic" from the old solenoid, wiring it direct and accepting the consequences of my actions. What's the worst that could happen? I burn up the old solenoid, cause an electrical fire and watch the source of my irritation go up in a mushroom cloud. I guess I'd better stop at the store and get a bag of marshmallows just in case. I'm open to any and all input.
You're spot on with the solenoid wires, blk = ground, red = hold (ignition circuit), white = pull (high amp temporary circuit). There is a module out there (and not made in China) that will do what you need John C, but for the life of me I can't remember what it's called or where to source one. So, on to plan B: you have your ground, you have your ignition input to red wire, you just need a high amp input for white wire. Simple, Bosch cube relay. Install a cube relay near the solenoid. Run 12 ga wire from starter battery lug to relay terminal 30. Run another 12 ga wire from term 87 to white wire. Run a 14 or 16 ga wire from start terminal of starter to term 85 on relay, ground term 86. Of course this would be for an engine that fires off quickly. If it has to crank for many seconds, you risk roasting the fuel solenoid. Also, make sure you get a Bosch 40 to 50 amp relay, not a China knock off that's only good for 20 on a good day.
Oh, forgot to say this, if this is an engine that you have to turn the key on and wait for glow plugs to warm up, plan B is out the window.
Glow plugs are on the key turned to the left. Does the cube relay have a current limit? This unit does not have a fuel solenoid. It has an electric fuel pump running off a separate timer set off the key. I'm just trying to get the relay to do anything at all. I'll let you know.
I can't recall exactly what amps the pull coil drags, but I doubt it's more than 10-15 amps. You can get Bosch cube relays up to 50 amps. Using one of these will provide a solution for the pull coil wire on your solenoid, however, it's not the ideal fix. In particular, if the operator simply turns the ignition on, but does not right then turn switch to "start" position, the pull coil is not being activated leaving the hold coil to try and pull the plunger in, this can burn up the solenoid as well. The best solution is some form of pull coil timer module.
The saga of the solenoid is solved. We cut off the "piece of magic" and joined the green to the black lead and the white lead to the black lead and touched them to the appropriate battery terminal and the plunger plunged. We joined the appropriate leads to the harness connector, flipped the key to start and low and behold the plunger plunged again. Removed the new solenoid from the engine and installed the old modified solenoid. Turned the key to start and the plunger did its thing and the engine fired on the first cylinder to pop over center. The next test was turning off the key and the engine died on cue. Final test was re-starting and shutting the engine down with the emergency button. Again the engine expired on cue. Taped up all the connection points to seal them and closed the hood on the job. Semi happy customer. Now they get to try to turn the new non-working solenoid back for credit. The upshot to all this mess is that the "MADE IN CHINA" syndrome strikes again. The "piece of magic" called a "CURRENT COMMANDER" went bad on the old part and was no good to start with on the new solenoid. I figure that the engine starts so well that the "CURRENT COMMANDER" is not needed. The scenario that would have required it would be the engine running out of fuel and have to be turned over for some minutes in order to bleed the fuel system back in. Since this machine has an electric fuel pump that runs whenever the key is in the on position, that would shorten the number of times the engine has to turn over to fill the fuel injectors. That amount of time should be well within the heat tolerance of the solenoid. Customer was told of that situation and that to fix it factory would require some other type of system that would cost more totally and on top of what was already spent on this job. Job was marked "FIXED, GOOD ENOUGH".
Excellent!