Late model Massey Ferguson 135 wire diagram

Jed P.

Member
Hello everyone. I bought a shop manual and a new 5 piece gauge set for my Massey Ferguson 135 deluxe, I have some questions about installing these new gauges. First question is: The new gauges have lights installed, the old gauges have no lights......How do I wire all of the new lights?
 

I know the outer case of the light is grounded and the spade would need a 12v supply, should I run a red wire and branch off to every light lug? Where should the 12v line originate from, the light switch or somewhere else?
 
I would run 1 wire from the light switch and branch off it to the lights. No need to have the dash lights on all the time
 
(quoted from post at 22:12:10 04/25/17) I would run 1 wire from the light switch and branch off it to the lights. No need to have the dash lights on all the time
I will do that, thanks.

The next question is: The wire diagram in the shop Manual shows a Voltage Regulator with wiring routed to it, it also shows a Generator with wires running to it as well, on my tractor I see the Generator/Alternator but I see nothing else that has wires running to it, there seems to be no "Voltage Regulator", am I not looking in the right places? I cant find the VR.
 
(quoted from post at 09:21:41 04/26/17) It may have been converted to the single wire GM alternator that has a internal regulator.
Thanks PTfarmer.

There is a box above the ignition switch that has a black and red wire coming out of it, the only thing I can see written on it is "wico", the black wire is the ground main and is gang plugged into all of the dash gauges but the red wire has a female lug which is unplugged, I can not tell where it should be plugged into, any idea what that red wire is for or what the box is for?
 

I may be assuming the gang of plugs are a ground wire however. I am also doing some internet research along with the shop manual, the box may be an inverter, if that is true is the real "Power Source" to the inverter coming from the light switch which is energized by the ameter which is energized by the starter solenoid?
 
That little box on the top and back side of the battery box is the original powersupply for the original lights. New gauges and lights are all 12v and do not need that supply anymore.
The voltage regulator will be on the left side right under the dash and assuming it's still used has 3 or 4 screw down connectors on the side of it. Did someone convert it to internally regulated alternator and just leave the old regulator attached for some reason?
 
(quoted from post at 12:19:30 04/26/17) That little box on the top and back side of the battery box is the original powersupply for the original lights. New gauges and lights are all 12v and do not need that supply anymore.
The voltage regulator will be on the left side right under the dash and assuming it's still used has 3 or 4 screw down connectors on the side of it. Did someone convert it to internally regulated alternator and just leave the old regulator attached for some reason?

Near as I can tell there has been a conversion, there is now an Alternator on the right side toward the front, I quess they have an internal VR.
 
so if the yellow wire from the Ameter energizes the light switch at terminal 5, can I bypass the inverter and attach the 12v lights to terminal 4 on the back side of the light switch?
 
Don't have a diagram handy but whichever terminal provides power to your headlights is the one i would tap for the gauge lights.
 
As I look at the wire diagram in the shop manual, I see nothing labled power supply but I do see an inverter and the original gauge lights came off of it, the inverter is energized from the Light switch which is energized from the Ameter which is energized by the starter solenoid.
 
We are talking about the same part right?
48184.jpg
 
Yep, that looks like it and I have no reason to doubt your terminology of "Power Supply", I just dont see it called anything besides inverter in the shop manual.

I see the pigtail with 5 female lug connectors which is attached to the black wire coming off the "power supply", the red wire ( short wire) has a femal lug connector and after looking around I believe it plugs into terminal 4 on the light switch.

I suppose when I get all the gauges changed out, I can try to run the gauge lights through the "power supply" and if that dont work I will disconnect the 5 plug Pigtail and attach them direct to terminal 4 from the light switch and try again.
 
Dug my diagram out and sure enough it does label that "inverter". Odd... It's the same thing though. Post 4 feeds the power supply/inverter so you should be able to just tie that post right into your new lights and be done. Eliminate the supply all together.
 
(quoted from post at 14:09:57 04/26/17) Dug my diagram out and sure enough it does label that "inverter". Odd... It's the same thing though. Post 4 feeds the power supply/inverter so you should be able to just tie that post right into your new lights and be done. Eliminate the supply all together.

I will try that then, thanks.

The original oil pressure gauge Has a fitting that screws onto the gauge, the device that screws on is a round white disc and has two spade lugs on it, there is only one wire that goes to the disc, any idea what that contraption is? Should there be two wires running to it?
 
I had done some reading around the web when I discovered the presence of an inverter, seems the standard answer was that the original instrument lights were some type of small neon bulb and the inverter was needed to provide A/C voltage to run them.
The use of common D/C 12v bulbs would have to bypass the inverter altogether.

My WAG as to why such a system was used would be that neons would be more resistant to vibration?
 
(quoted from post at 18:03:09 04/26/17) I had done some reading around the web when I discovered the presence of an inverter, seems the standard answer was that the original instrument lights were some type of small neon bulb and the inverter was needed to provide A/C voltage to run them.
The use of common D/C 12v bulbs would have to bypass the inverter altogether.

My WAG as to why such a system was used would be that neons would be more resistant to vibration?
That makes sense, I wonder why the new gauges dont use LED's?
 
LED's don't radiate light like incandescents do. You would end up with a hot spot of light in the gauge with half of it dark. Look at LED light bulbs for household lamps. They have LED's mounted so they point in every direction. These gauges are to small to do that effectively.
 
The original oil pressure gauge Has a fitting that screws onto the gauge, the device that screws on is a round white disc and has two spade lugs on it, there is only one wire that goes to the disc, any idea what that contraption is? Should there be two wires running to it?
 
That sounds like the oil pressure switch used on diesels. It should have two wires hooked to it, assuming it hasn't been bypassed.
 
When I look at the wiring diagram in the shop manual, the only wiring going to the oil gauge is the light circuit and does not show the pressure switch. Right now, the only wire leading to the switch comes from the Alternator. Do you or any others reading this know what wire should attach to the other spade lug on the pressure switch and where that wire would come from?
 
It should come from the ignition switch to the pressure switch then down to the alternator. Here is a big dean picture that summarizes it. Some minor variations but you'll get the idea.
48201.jpg
 
How do you get pictures to show up? I have tried a couple times and it does not show them. If I can get pictures to show, I will post one of my dash with gauges.
 
When you go to reply the section below is the advanced posting section. Click upload photo and browse to what you want to upload. Click upload once selected and continue once the thumbnail displays. It will upload the photo and put a link in the reply box to the photo. When you submit the reply it will just show up.
 
(quoted from post at 07:39:47 04/27/17) It should come from the ignition switch to the pressure switch then down to the alternator. Here is a big dean picture that summarizes it. Some minor variations but you'll get the idea.
48201.jpg

I will post this as a quote so we can compare this pictorial with my new gauges, all I have done so far is connect wires the same way they were as I found them on the original gauges.
 
Is this oil pressure switch only used to light an indicator light when oil reaches a certain pressure?
 
Common pressure switch,probably had a warning light at one time, not factory AFAIK.

I would eliminate it unless you want to add warning light again.

My question is whether there is a T under it for the oil line? If not, it's just a cap. Hard to tell from pic.
 
I would assume that block under the switch is a T. Otherwise that gauge will do absolutely nothing. They were used on the early diesels to energize the system once a certain oil pressure was reached. 5psi if i remember right.. The way you have it now it might as well not even be there as it's not controlling anything.
 
Yes, there is a T under the pressure switch with an oil line port.

If I understand correctly, I do not need the pressure switch then?
 
What the oil pressure switch does is supply power to gauges like the fuel level gauge. When the pressure switch gets oil pressure it closes the circuit so power can be supplies. When you cut the tractor off the oil pressure goes away, and switch quits sending power to whatever needs it. The diesel doesn't have a ignition switch, it just has a starter switch
 
Brilliant observation! Yes, it does make sense that the pressure switch is used to energize the gauges.

I appreciate the input from all of you and feel confident that these new gauges will be working properly when I fire up the tractor this week. Right now I am waiting on a seal kit to repair a power steering fluid hemorrhage I had the last time I ran it.
 
I noticed that the original fuel gauge and the new one do not have the same number of connection points. I took a picture of them side by side to show. Notice the T and the B terminals, what do the letters indicate? Also on the new gauge there is a terminal labeled 12v and the original does not. Can anyone clarify for me?

This new gauge set did not come with any form of connection diagrams.
48289.jpg
 
The instruction sheet that came with the gauge should explain it. Typically B is battery, T is tank and the bottom one there is the ground. Some sending units require a ground wire to return to gauge to function correctly. That is where it would hook up. The fat one at the top is of course the bulb.
 
Thanks for clarifying, as stated above, there were no instructions that came with any of these gauges, I got them off of ebay as a set of 5, each was wrapped in bubble plastic and put in a white box with hand written lettering labeling each one.
 
I have a question for Rockepg.

If you look at the pictorial you showed above, there is a brown 16g wire coming from the neutrality switch and a black 10g wire coming from the - side of the ammeter, both wires connect to the starter solenoid, should they be connected to the same position on the solenoid? I cant quite make it out in the pictorial.

After I got the thing back together and fired it up, the gauges do not work but the new lights do, im not sure if I have a short somewhere or not. Currently I have the black wire from - position of the ammeter attached to the same large post that the + battery cable is hooked to.
 
Ok so those two, brown and black, wires are the connection to the battery. Everything merges on the back of starter like the pictures shows. Same post as the heavy cable going up to the battery. If you have it hooked up properly then you should see a slight discharge in the ammeter when it's running until you give it enough rpm to kick in the alternator charging. Then the needle should swing positive.
When you say the gauges do not work.. any of them or just one or.. ? Oil pressure and temp are mechanical so those should at least work.
 
Either the oil pressure switch is bad, or the amp meter is bad. See if you have power going in, and out of the amp meter, the amp meter should have power going in, and out all times. With the engine running see if you have power going in, and out of the pressure switch.
 
To that point.. Jed did you wire up that pressure switch or just bypass it? One of the original pictures you posted had only one wire going to it.
 
On the same day that I posted that my gauges did not work I discovered that the pressure switch did not work, I took it off, clamped it in my vise, hooked a continuity tester to both terminals and hit it with air pressure, I could hear a click inside but the circuit did not close.

I bought a new pressure switch and now the gauges seem to work, the only two gauges that need positive power are the ammeter and fuel gauge.

While the engine is running the ammeter shows 20 on the scale, im not certain if that is where it should be.
 
I started the tractor and took a picture of the dash while it was idling, notice where the ammeter needle is.

Also, notice that the tach is not moving, it is a clickwise rotation gauge, I wonder if it should be counter clockwise, when I look towards the back of the alternator while it is running (sitting on tractor seat), the cooling fins run counter clockwise.

48513.jpg
 
Hook a volt meter to the battery, before starting the battery should be something in the 12 volt range. After you start it your volt meter should go up to around 14 volts, that will show if its charging. If you have lights turn them on, and observe the volt, and amp meter. The volt meter, and the amp should drop slightly. If it shows to be charging, but the amp gauge constantly shows 20 amp the voltage regulator could be bad, unless the battery had been run down, and hadn't been put on a battery charger. You can also touch the battery, if it starts getting hot it could be overcharging. It can also boil out the electrolyte solution in the battery (kind of like a over heating radiator). These are just things to look/check for.
 
Remember alternators work much differently than generators. It's not unusual for an alternator to read like that when you first crank it up. Especially if the battery is discharged a bit. Let it run for a while and see what it does. It will most likely settle to 3-5 amps after a while unless there is a problem like ptfarmer said.
 
@ PTfarmer -- I will try the volt meter today, the grass in the field is about a foot tall now and I need to hook up the mower soon.

If the "voltage regulator" proves to be bad, I will need to buy a new alternator since it is inside the alternator correct?

@ Rockepg -- Im not sure what to do with that gaping hole on the dash, several options come to mind including stuffing a bouquet of daisies in it :D lol, I assume thats where the idiot light used to be.
 
On the Perkins engine the tach is run off of the back of the engine (driven off the camshaft) so the tach would need to run counter clockwise (the one you have runs clockwise). The clockwise tach is used on the 135's with the Continental 4 cylinder gas engine since it runs off of the generator, or alternator. On the alternator with the internal voltage regulator, the regulator can be changed out so you don't really need to replace the whole alternator. Since you have been doing electrical work the battery could be just run down, and it just needs to be recharged if you didn't have it on a battery charger. The battery if its old could possibly be going bad, you could unhook the negative battery cable from the battery while its running, and see if the amp gauge goes back to 0. On a diesel you really don't need the battery after you start it so you could just unhook the battery (I have done that on diesels that had been overcharging just so the tractor can be used). If its a diesel you can fill it with fuel before you start mowing, and you should run out of daylight way before you would run out of fuel.
 
I just went out and attached a volt meter to the battery without the engine running, it was a little over 12 volts. When I started the engine I got 14.7 volts, this time the amp meter was between 10 and 13 amps. I disconnected the negative line while it was running and the amp meter dropped to 0 to 3 amps. I cant get an exact reading because the needle bounces around with the vibration.
 
This diesel engines does get great fuel economy, i ran a cultivator over about 3 acres the first day, I came back to the shop to top off the tank and hardly any of the fuel was gone.

I also have a Ford Golden jubilee with gas engine, the previous owner put a 3 gallon tank on it, when I pulled the same cultivator over the same field, I would run out of fuel with about 1/4 of the field left to do.
 
Sounds like it's charging a low battery. Let it run a while and see if the charge state approaches 1-3 amps. If it does then it's working as expected.
 
I let it idle for about a half hour and the amp meter went down to around 5 while idling, since the needle bounces it could be in that 3 amp range.

The old girl has been sitting for several years, I spent the last couple weeks going through everything I knew and greased all the moving parts, Im painting an implement that I just finished fabricating (3 point hitch spike tooth harrow) and hopefully dirt will be flying by tomorrow.

The help from you all has been highly valuable to me, thanks tons!
 
(quoted from post at 13:23:14 05/05/17) I let it idle for about a half hour and the amp meter went down to around 5 while idling, since the needle bounces it could be in that 3 amp range.

The old girl has been sitting for several years, I spent the last couple weeks going through everything I knew and greased all the moving parts, Im painting an implement that I just finished fabricating (3 point hitch spike tooth harrow) and hopefully dirt will be flying by tomorrow.

The help from you all has been highly valuable to me, thanks tons!


Sounds like everything is good.
 
Spent about 3 hours with a six foot mow deck, the only thing that was not working was the water temp, I will check thermostat tomorrow.
 
Spent about 3 hours with a six foot mow deck, the only thing that was not working was the water temp, I will check thermostat tomorrow.
 

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