Hello folks, I have a 7FGU30 that's been giving me fits. Let me try and explain the behavior and some of the steps already taken. No crank No start Checked all grounds, all fuses, all relays. All test fine. When starter relay contact terminals are jumpered, it will crank but will not fire. Tested voltage at starter relay coil terminals and not getting ground to the ground terminal of the relay coil when start switch cranked. The strange part is when trying to crank, I actually get a positive 12vdc to both coil terminals of that relay but no ground. Checked for broken or damaged wires but did not find any. Regulator solenoid seems to be getting power as I can hear it click when trying to crank. When spraying starter fluid into the air box and jumpering the starter relay contacts, it cranks and sounds like it wants to start but never does. So I'm at least getting spark. Both the no crank and no start issues happened at the same time so I feel they are likely related. I may be way off here but I am suspecting possibly an ECU issue. There is an ECU underneath the left foot step with a part number of 24610-U2201-71 that a mechanic friend suggested to swap out and try but I really don't know what this ECU is responsible for and I would rather just not throw parts at it without being fairly confident that this is the issue. I would really appreciate some guidance with this. I'm just at a point where I feel totally defeated.
The seat safety switch is probably on the fritz. Check the easy stuff, first.
We did have problems with the seat safety switch in the past but I did not think that would actually prevent it from cranking? The issues we had with the seat safety switch was it would sporadically prevent operating the levers/hydraulics and the seat light would also sporadically illuminate. One of our guys disconnected it and jumpered the two wires together. This solved the problem for about a day but then the seat light started to flash. So I reconnected it as it was intended originally. However, can the seat switch cause a no crank? In the past we have always been able to start the machine while nobody seated in the seat.
Welcome to the HEF, BTW. I had some 7FGU30 units I took care of at a petroleum warehouse. I don’t recall them being able to crank unless a butt was in the seat. I could be wrong. I would try and rule that out, before you spend anymore time troubleshooting.
I agree. I will look closer at that. How do you suggest I troubleshoot the seat switch? I know when you sit in the seat, the instrument light goes off. When you raise your butt off the seat, the light comes on. So I assume it must be working. Is there another way you would suggest to verify that?
If you can get a schematic for the machine, we could more likely help you. Simon C
Hello Simon, this is what I have.
Only thing I missed is whether it is gasoline, Diesel or propane as different schematic each, but looked at and decent schematic. Please respond. Simon C
Hi Simon, my lift is propane only. Also it is a single speed. No EZ-pedal if that helps
Thanks will look and see if I can suggest anything simple. Simon C
Thank you Simon
Okay so you have no crank and no start. #1 Go to the starter relay and it has a large wire coming into it (White/Blue I believe ) and going out to the starter solenoid by means of a large black wire.-----Check for 12Volt power with a meter at the wire coming out of the relay with your red meter lead while your black meter lead is on battery Negative and someone else holds the key in the start position. If you do not have around 12 volts there the relay is junk, or the source feeding it is faulty( 40 amp fuse ) or the control circuit is not working to excite the relay. #2 Check at same relay on the coil side to see if there is power to the positive side of it with key held in the start position ( It is a black wire smaller in size coming from the Shift controller ST- Terminal ) and goes to ground. Is there power here? While key is held in Start position how far does voltage go down with Red lead on Battery Positive. and Black lead on Battery negative. Lets start with these tests. Simon C
#1 yes I have 12v positive on the contact side of the starter relay. I can get it to crank by jumping the two terminals on the starter relay socket but it will not start. Relay is good. Tested it out of circuit. #2 yes there is +12v on the coil side of the relay but no ground on the other side (this is the problem). Voltage does not drop at all or at least very much when holding in start position and testing for voltage drop across battery terminals. A few fractions of a volt maybe.
If you have power on the ground side of the coil of the Starter Relay but no path to ground then you will have to follow it in the harness and repair or hook another wire to it and hook it to a good frame ground. If it cranks after that but does not start we can deal with the separate problem. Simon C
I will try to explain this next experiment I did as best as possble. Testing the two terminals of the coil side of relay socket with the key in the #1 position but not cranking I get the following results. Left side side terminal = ground Right side terminal = ground When holding key in crank position both these terminals go 12v positive. When one Shem should go ground in order to energize the relay but this is not happening. When performing the same experiment on a working lift, I get the same readings except when cranking, one goes ground. By the way, I need to clarify that the above testing is done with the relay itself removed. This is the odd part. What is giving the ground terminal a path to positive 12v? Seems to me that an ECU must be controlling this.
We did pull the fuse/relay box out and tied in a ground directly to the coil terminal that should be ground. It did crank but would not start
The ground side of that coil of the Start relay is actually positive until it gets inside the negative post of the battery, and is more so if the wire going to ground is broken completely. If you don't understand go to your car and disconnect the negative post and hold onto cable up in the air,, have your wife go turn key to start position and hold it there. The second you touch that negative cable on the negative post there will be a major arcing and maybe top of battery will blow off. All power is positive until it enters the negtive post when there is a disconnect before the negtive post. Don't try this unless you have a long stick to tie cable to, cause you will have an explosion. Now if you get it cranking but no start, we need to see if the power is going to the LPG Relay & LPG Solenoid. Hope you understand what I explained about positive until it enters the battery. But if battery negative connection is good you can take a wrench from battery negative to frame ground and should have only tiniest or no spark, not an explosion like above. Simon C
Hope I did not confuse you as the small wire being disconnected to Ground is what causes the confusion for people. Hope it helps. Simon C
Yes thank you Simon. I was not aware of that. I will pass on that battery experiment for now but I’m sure one day I’ll give it a shot. It would be interesting. So at this point it seems there may be a damaged wire. So I will go ahead and try to trace that wire. As for the no start, I can hear the solenoid click on the LPG regulator when trying to crank. I’m not aware of an LPG relay specifically but I did remove and test all the relays I could find and they all tested good. Do you by chance know where this relay would be located?
No you didn’t confuse me. Your explanation was clear and thorough and has educated me to some things I did not know
I am assuming that you are referring to the solenoid on the LPG regulator. Attached is a photo of the regulator. The solenoid marked #1, I can hear that click when cranking. The one marked #2, I cannot. Not sure what this one is. Also I should mention that the LPG regulator is new. It was recently replaced. The photo is of the old one but they are the same.
Okay so on schematic 16-27 you will find the LPG Relay and the LPG solenoid. It is the solenoid that will release propane into the engine. There is a 7.5 amp fuse that feeds it after the Ignition switch on the schematic. Have a look at that part and I cannot say where the relay is but the solenoid for the propane should be under the hood somewhee with a pipe that goes to mixing chamber then carburetor. Simon C
Sorry about that, and yes one of those will let the propane through. I am not no propane expert but I would think that one of them will get it going if the coil actually works internally. Did you by any chance change a propane bottle lately that had an extra sealing rubber in the hose connection stopping the gas from exiting the tank. With no flamables around you could crack the propane line coming towards the solenoid with good welders mitts on so as not to get burn't from the cold to ensure you have gas to the valve. I will check schematic for the other valve which may be some kind of shut -off, not sure. Need to start somewhere. Simon C
The LPG solenoid is fed by wire ( BY - should be black and yellow ), the ground goes to earth by wire ( W/B which should be White/black ). Your plug will show which is which and mark with black marker pen on the Solenoid to remember. The solenoid could click and not open the valve is a possiblity. Check if there is power to the B/Y wire while cranking. Hope we get it figured out. Simon C
Yes we did crack one of the propane lines at the regulator and it did shoot out propane.
Gotcha, I will check again later this week on that. I’ll try to drag the lift outdoors. Currently it’s in a very dark warehouse and my eyes are not what they used to be even with a work light
Thank you Simon, I will check everything you suggested thoroughly. Unfortunately I won’t be able to do it till maybe Friday as I have other commitments. But if you would please keep an eye on this thread and I will reply back just as soon as I have the info.
At your pace. Better to do some diagnostics and small wiring repairs before firing the parts cannon. Simon C
Thought about something else. Maybe there is a screen where the propane enters the manifold, is a possibility of something like that. Simon C
That’s a good thought. I’ll look into that as well
Simon, I got a thought. That second solenoid in the regulator that I asked you about, can it be a low fuel cutoff? I did some googling for a fuel cutoff solenoid for this lift and I came across part number 23620-23340-71 and it looks like the correct solenoid. I think I need to check power to this (along with all your other suggestions). If it is a fuel cutoff, supposedly there should be a relay that controls it so I’ll have to trace the wires back and see what relay it goes to and test there again. I’m thinking I might be able to just apply power to that solenoid and see what happens. But I do know that at no time do I ever hear this solenoid click. I’m referring to the one marked #2 in the photo
Found it on PG.16-40. There is a low pressure propane switch, relay, warning lamp. Maybe one of them is defective and no flash of engine. Have a look and you will need to do some checking. In my previous explanation about ground cables an easier way to remember is, if the ground cable is disconnected from Battery Negative Post then the cable is still positive, if the cable or wire is connected to Battery Negtative post it will be Negative when checking, because the energy used to turn fan or light bulb has been spent and only amps are going back to battery. Simon C
Yes power to the black/yellow wire while cranking. I tested the black/yellow coming out of the back of the ign switch. Probably not where you wanted me to test. Still trying to locate the black and yellow going to the relay.
Hi Simon, I have some good info. There were two relays mounted on a bracket adjacent to the main fuse box. I unplugged both these relays from their connectors and jumpered a paper clip across the contact terminals of the connector. The forklift cranked and started. I’m not sure what these two relays are for or why they are not getting energized. I’ve taken photos of the relay connectors hoping to show the colors of the wires going to them. I will look at the schematic and try to find them but I think this is good progress. Attached are the photos. I took two photos of each (bottom side and top side) to better show the wires
So just from experience you could simply have some dirty plug ins. They do look fairly dirty to me, and could use some high pressure air to clean out. Also good to check all female pin receivers to see if one pin is a little loose. Have seen too many times to remember especially if lots of hours. Page (16-40) had the propane solenoids and valves. Might be an idea to clean as many connectors as possible to rule out loose pins or corroded contacts in a plug. Simon C
Yes just about every connector I disconnected was really dirty. I did take some starter spray and cleaned out all the ones I disconnected before plugging back in but I will go through them all and check for loose pins as well. At this point I’m trying to identify those relays in the schematic based on the wire colors going to them. But unfortunately I haven’t been able to identify them yet.
Be mindful of relays with 4 or 5 pins. There needs to be only 1 loose pin receiver for a relay to not work. I have some different pins for testing all female receivers to make sure they are all tight. Simon C
These relays all have 4 pins (2x coil & 2x contacts). These are both Normally open relays. The relays themselves are good. Tested with multimeter.
Just to tell you how prevalent it is , loose pins. I have a customer with Case TV380 Track machine that would start and die from blown fuse within 2 minutes of running. I changed the relay that was associated with the blown fuse and still blew the fuse. So I proceeded to slowly tighten all the female receivers of the relay and all the relays around. That was 2.5 years ago and the machine has never died since. Another thing to watch out for is Relays with Normally closed contacts that look exactly the same as those with normally open contacts. Ran into this about 3 weeks ago, and it was not the problem. A diode installed backwards was the problem. Need to dot every I and cross every TEE. Simon C
The relays are the same ones that have always been in it when it was running previously. I removed them and used a 9v battery to test them as to not blow the internal snubber diode. Using my fluke, I put the meter in continuity mode and clipped alligator clips to the contact terminals of the relay itself. When energized with the 9v battery with polarity correct, the relay clicks and I have continuity through my meter. So both these relays are functioning. They are normally open relays. But as you mentioned, I need to more carefully check for loose pins. I didn’t see or feel any but it’s possible I could have overlooked something either on those relays or somewhere else. By the way, I did previously unplug every relay in the machine and test the relays in the same manner mentioned above. It was time consuming but they all tested good. We’re getting closer for sure. I just wish I knew what exactly I jumpered when I jumpered the contact terminals on those relays and the machine started and ran. I’m beginning to think that maybe these schematics I have are not the right ones for some reason. I can’t seem to find the corresponding colors. I have to any of the relays in the schematic.
Was looking at your schematic some more and on Page (16-40) an LPG pressure switch feeds three more switches and a lamp. If that pressure switch is bad something will not work. So powering up the relay coil with a 9 volt battery is good, but the problem is that the load carrying contact pins on the relay need to be hooked up to a 5 watt bulb from a separate small 12 volt battery. I bought a small AGM battery specifically for doing these tests. Your Fluke meter will always show perfect continuity with only the weakest of contacts or partially burn't contacts. Problem is that it won't run what it was designed to run. Sorry but none of your relays have been load tested, they have only been proven to have coil circuit working. Well actually whatever relay was working when it cranked is probably fine but not sure which one it was. Simon C
Agreed. Continuity testing is not a guarantee that a particular wire can carry the required current.
Well I do have some new relays. I can always throw them in and check. I think you may be on to something with the LPG pressure switch. I need to check that but I don’t really know what to look for and what it looks like. Do you have any pointers on what I should be looking for? Also page 16-27 shows “Engine Rev SW” that is tied into LPG relay. What is the engine rev sw?
Not certain what the ( Engine REV Switch ) is . Maybe for revving up the motor, not sure. That LPG pressure switch ( Page - 16-40 ) where ever it is hiding needs to be proven to have power coming into it and going out of it. It should be on some kind of propane line sensing propane pressure is my guess. Simon C
I’m with you 100% on this and for some reason I have a very good feeling about it. I’m going to try and Google that part to at least get an idea of what I’m looking for.
The LPG Pressure switch is powered by a RED/Blue wire ( There letter L on the schematic is blue from what I know ) . The power exits that switch in the colour Black / Yellow. Look at every pressure switch that is tied into propane and you will have it. It will be there somewhere. Simon C
You’re right. It will be there and I will find it. I wonder if it’s back near the tank somewhere. I haven’t looked there very well
You will find it, I am sure. Simon C
Thank you for all the help Simon. I appreciate you so much!!
I guess it should look something like this. Shouldn’t be too hard to find.
Theoretically it seems that I may be able to test it by jumping the two wires together. Would that be an option?
It will be on a brass block, or on some housing measuring propane pressure. It can be removed if that style and tested with super low pressure to see if it switches, and if the contacts can carry a load. Simon C
Yes for a quick test, but not left that way so that some innocent person don't get killed. Simon C
Yes of course I would never leave it that way. I’m just thinking for a quick test before firing the parts canon
will it be carrying a positive or ground signal?
It is carrying positive power, battery voltage. A test light or something that draws some current would be best to ensure the contacts can carry some power. Simon C
Thank you, will use a test light
Hi Simon, I had a chance to work on that lift today. Looked all over for that pressure switch but could not find one. Got desperate and hit up ChatGPT and it said that the LPG Fuel lockoff solenoid and the pressure switch are incorporated together on this machine as part of the LPG regulator. This makes no sense to me as the lockoff solenoid only has two wires and its strictly a solenoid. doesn't look like there are any signal wires that can go back and trigger a relay anywhere. As it stands, if I supply ground to the ignition relay AND the LPG relay, it will crank, start, and run. I did my best to check for loose pins on the majority of the connectors but found none. I know an easy solution would be just to tap in a ground to both those relays mentioned above but I just don't feel thats the best solution. I'm fresh out of ideas. The schematics I sent you are supposed to be the right ones but many of the wire colors are just not matching up to what I'm seeing on the machine.
That can pose a real problem if wiring is different. Not quite sure what to say other than look on other forums for a perfect schematic. I had the same problem on a Case Track machine that the first schematic that I paid for was totally incorrect. They then sent me the correct one that the wires matched up with. Simon C
If wire colours and components don’t match up there is a good chance that the schematic you have is the wrong one.
Yes I agree, I’ll have to look for the correct schematic.
Simon, I’m still trying to get a correct schematic but I just had a quick question for you. Is it possible that the grounds for some of these relays is actually sent through an ECU?
I recall seeing the grounds going to frame only, or strap. Sometimes it is the flat braided style, sometimes it is welding cable style. Simon C
Yeah there are a couple big grounds going to frame. They are all good. Just no ground to the starter, ignition, and LPG relay coils. I tapped in a ground to the LPG relay and Ignition relays. Didn’t have to worry about the starter because it looks like the starter and Ignition relay share a ground. It’s working. Starts and runs normally but someday I would like to get to the source of the issue and understand what it was that has been giving me this huge headache
Will tell you later today how to properly test some of the poor connections that I know are happening. Just on my way out for 1/2 the day. Simon C