Toyota 7FGU30 No crank/No start please help

[Simon C]

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.

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.

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

 

[Nige]

Agreed. Continuity testing is not a guarantee that a particular wire can carry the required current.

 

[WaelB]

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?

 

[Simon C]

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 I 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

 

[WaelB]

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.

 

[Simon C]

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

 

[WaelB]

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

 

[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

 

[WaelB]

Thank you for all the help Simon. I appreciate you so much!!

 

[WaelB]

I guess it should look something like this. Shouldn’t be too hard to find.

 

[WaelB]

Theoretically it seems that I may be able to test it by jumping the two wires together. Would that be an option?

 

[Simon C]

I guess it should look something like this. Shouldn’t be too hard to find.

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

 

[Simon C]

Theoretically it seems that I may be able to test it by jumping the two wires together. Would that be an option?

Yes for a quick test, but not left that way so that some innocent person don't get killed.
Simon C

 

[WaelB]

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

 

[WaelB]

will it be carrying a positive or ground signal?

 

[Simon C]

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

 

[WaelB]

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

 

[WaelB]

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.

 

[Simon C]

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

 

[Nige]

If wire colours and components don’t match up there is a good chance that the schematic you have is the wrong one.