Ford New Holland 1920 starting issue

[RobertBrown]

I have an intermittent starting issue with this machine as of late. I hoping for some help in solving this problem, maybe someone has tracked it down before.
The problems started weekend before last when the tractor would not start, nothing would turn or even click in. I put my meter on the battery and there was only 10 vdc so I removed it and put it on the 10 amp charger for an hour and then on the 2 amp for about 26 hours. The voltage was up to 12.5 but the charger indicated it was not fully charged, looking at the LED lights on the trickle charger. I put the battery in the tractor and could not get the machine to crank, nothing. I did not have time to work on it, so the next day I read the voltage....10.5 vdc....bad battery.
Took the battery to NAPA and had them test it and it was toast, so I replaced it. The battery was in the tractor when I bought it so I don't know how old it was but I owned the tractor for over 5 years. I also replaced the ground strap with a new ground cable as the old strap was really corroded.

The new battery started the tractor fine....once. Pulled the machine out of the garage and put the mower on it, shut it off and went back about an hour later and nothing. I removed the neutral switch on the column shifter and tested it. It tested OK but I had my doubts.
I thought I had a bad neutral switch as I could get the tractor to start but only after I played with the shifter while holding the key.
Now I can't get anything to turn or even click no matter how I move things, but I still have continuity through the switch when the tractor is in neutral.
I have checked both neutral safety switches and they are both functional or have continuity.
I'm thinking I need to test the starter solenoid.
What is the best way to test this conclusively?

Thanks for your help.

 

[PoorPlowboy]

I've always tested solenoids first by making sure there is 12+ volts being supplied to the signal wire (smallest of the three terminals on solenoid) by the keyswitch. If you suspect key switch trouble, make a double ended jumper wire with alligator clips to supply start signal direct from battery. If it doesn't start, use a set of heavy gauge jumper cables to jump the two big lugs on the solenoid. If it starts, then you have a bad solenoid. Be certain that you are delivering 12+ VDC to the start circuit terminal. If it starts be sure to yank the jumper from the start terminal in case the starter bendix tries to stay engaged.

 

[RobertBrown]

Thanks ......sounds like good advice
I'll give that a try.
The solenoid is hard to get to, it is in between the starter and the engine but I have the schematic.
Hope fully I can get to it without removing

 

[Soundguy]

double check that battery voltage again.. then check power to the solenoid when in start position. a test lamp will likely work better than a meter.

if the lamp comes on in start, check voltage. if 12v.. then look at solenoid or starter.

 

[RobertBrown]

double check that battery voltage again.. then check power to the solenoid when in start position. a test lamp will likely work better than a meter.

if the lamp comes on in start, check voltage. if 12v.. then look at solenoid or starter.

Thanks
I'll try that tonight and let you know how it works.:thumbsup:

 

[RobertBrown]

I was unable to spend a lot of time on this tonight, but I wanted to check batt voltage at the very least.
The battery has 12.66vdc So I don't think I have a draw on it.
I did disconnect a reletively large(12 ga.) red wire from the starter. I put the neg. Lead to the battery (ground) and tested the red wire as I turned the key.....no voltage.
I'm not sure what this wire is for but based on it's size and color.....I think it's the one.

 

[Soundguy]

Traced it back to see where it goes

 

[kirkawilson]

View attachment New Holland 1920 starter solenoid shunt.pdf

My go-to method for starting my 1920 is to 1) unscrew the starter protective sheet metal strip nearest the seat, then rotate strip up and out of way for access to starter; 2) unplug starter solenoid spade connector and pull back rubber boot from starter battery connection; 3) make sure tractor is in neutral; 4) use 2 long screw drivers to shunt between the starter battery connection and solenoid. If your tractor starts every time like mine, the problem lies in the tractor wiring and safeties which are extremely difficult to troubleshoot. One could also permanently mount and wire a push button to bypass the tractor wiring and shunt-start the tractor. I have lost patience with electrical wiring issues and just am extremely careful when I shunt-start to make sure the tractor is in neutral because it will run over you if not.

 

[Soundguy]

if it is a tracgor wireing issue.. it is too easy to just bypass and scab wires ont he outside of the loom and start it safely vs screwdrivering it. and hoping the clutch ain't stuck!

 

[RobertBrown]

I had some time tonight to trace the wire.....
battery voltage is 12.67vdc
The large red wire traces back to the ignition switch. I don't think the clutch is stuck as I pushed the tractor in the garage. Also there is no sound coming from the starter coil....
I'm thinking the ignition switch should be investigated or otherwise tested.
I need to get this fixed tomorrow as the grass is getting high. We get rain everyday here and I'm have a lot of work as of late.
It's nice because everything is very green and the temperatures are bearable.

 

[Soundguy]

my comment ont he stuck clutch was aimed at the screwdrivering comment by the prev poster... starting the tractor fromt he ground is a great way to become a statistic..

 

[RobertBrown]

my comment ont he stuck clutch was aimed at the screwdrivering comment by the prev poster... starting the tractor fromt he ground is a great way to become a statistic..

Oh...I didn't notice that post.....
I don't do the screw driver thing, Sparks are bad....Sparks scare me...but thanks for the information.
Hopefully I can keep the safety switches in tact as I can be easily distracted and I'm a firm believer in Murphy, his law, and statistics

 

[RobertBrown]

After lot of testing, dis-assembly and deduction I have arrived at the following:
The problem lies with the safety start relay. This is the culmination of the circuit containing the neutral switch and the P.T.O. safety switch. This circuit operates a relay and closes an n/o switch that allows the starter solenoid to operate.
I have tested and re-tested all of these safety switches, the relay and the ignition switch. All switches/relays function as they should when tested with a meter, and meter with a power source.
The really weird part is the relay works when tested with a power source but will not when plugged into the connection provided. I tested the connection with my meter when turning the ignition switch and I have 12 VDC, but the relay does not operate. it took me to long to figure that out. I am now a lot more familiar with my machines electrical system, but I'm not sure if I should replace the relay or not.
I have located the part. It turns out that same relay is commonly used by an import car maker. The manufacturer is still around but like most it now has a different name. The really cool part is I can get it at Rock auto for about 27$ plus shipping and it will plug right up.

So...why would the relay work with a separate power source and alligator clips but not when plugged into the receptacle provided?
first thing that comes to mind is negative ground. When I tested the receptacle I grounded the meter to the battery. I don't know how the relay is actually grounded during normal operation. Perhaps the problem lies there.

I have a wiring diagram for that machine and it indicates that there are 3 safety switches...... I can only find 2. The manual indicates there are only 2.

 

[PoorPlowboy]

Check mouser if you have the info on the relay. They save me a lot of money.

 

[RobertBrown]

Check mouser if you have the info on the relay. They save me a lot of money.

tried it...no luck. Probably because it's an automotive application?

 

[Soundguy]

the meter has a megaohm input inpeadance at least.. probably more. that line will show as 12v on the meter to the relay. but under the real load from t he relay.. it like drops off.

could be a bad safety switch contact ( either of them ).. or bad wire connector.

to test this. hook relay up and keep meter on the line that goes 12v. then operate tractor as you would. see if you still get 12v there.. or something lower.. like 0-8

 

[RobertBrown]

So your saying there may be voltage but no current or insufficient current, not apparent by the using the meter.
I suspect the neutral safety switch and I plan to dissemble that next weekend. At that time, I will post photos.

 

[Soundguy]

Exactly, the meter could see 12v nut the line may not carry it under any real load, its at least something to test since you say the relay operates fine if you jump power to it externally, and the trigger line to it shows 12v on a meter, that would be my next check, voltage under load, I'd it is too low, relay won't pull in

 

[RobertBrown]

During my testing I noticed some significant voltage drops and some warm wires as I was turning the key and starting the glow plugs to test the circuit. Eventually I removed 3 wires from the Ig. switch so that I didn't blow a fuse or kill the new battery. So I was thinking that the glow plugs may be the culprit or something in another circuit that brought this whole thing on to begin with.
I'm wondering if I can't just remove the plugs from service as I think the machine will start fine without them. I may have a problem with the the timer.
The machine would not run without all 3 of the wires connected as 1 of them went to the fuel shut off (2 of the wires joined immediately after the switch). That makes me think the switch is not the correct one although the installation looked like factory....to me

 

[Soundguy]

i think i'd leave glow enabled.. as it should still help it to start easier.

if you are worried about the draw thru the control ckt. rig it with a push button and solenoid