Ford 1700 start aid quit working ?

[rayikeo2]

I have owened this tractor for 25 years. Durning cold weather I always use the start aid to pre heat before starting. It has always worked and started my tractor while out in the unheated shed. It coil quit glowing through the view hole when turning the Ign Switch counter clockwise and holding about 30 seconds. It worked (glowed) off and on for a while. My question is which part may be the cause: 1) The start aid coil, 2) The ignition switch, or something farther down the line to the cylinder heaters? How can I test this problem without replacing multiple parts? All you experts please give me some advise.

 

[JC-jetro]

I have owened this tractor for 25 years. Durning cold weather I always use the start aid to pre heat before starting. It has always worked and started my tractor while out in the unheated shed. It coil quit glowing through the view hole when turning the Ign Switch counter clockwise and holding about 30 seconds. It worked (glowed) off and on for a while. My question is which part may be the cause: 1) The start aid coil, 2) The ignition switch, or something farther down the line to the cylinder heaters? How can I test this problem without replacing multiple parts? All you experts please give me some advise.

Ray,

Get a test light or a voltmeter, check voltage or light when you glow-plugging. If you got no juice then you have a bad connection, broken wire or a bad switch. Before I change any components, I'd use a piece of wire and directly connect the glow plug to the battery positive terminal and then try to start to see if it starts. Glow plug is easy to take out, you can directly hook it up to the battery for few second and see if it gets warm or use a non-contact infra red heater to read the temp. do not do it more than 20 seconds for checking. The glow plug circuit is quite easy on 1700. just need to slowly eliminate the potential causes. Let us know if you need more details.

JC,

 

[Hooked_on_HP]

One thing to look close at is the glowplug indicator lite. It is not a lite. It is part of circuit. As voltage passes through the wire it gets hot and glows. Like JC says, get a test lite and start at the ign. switch and follow the wires to the glowplugs cheching at every connection.

 

[JC-jetro]

Below you can see the picture of the glow plug heater as Bill mentioned. The heater is in series with the plug carrying the juice and body ground completes the circuit. potentially if you preheat for too long the resistive wire may burn same as what happens to light bulb filament and opens the circuit. I'll check with the voltage there but jumping the termination contact should bypass the heater as well.

JC,

The whole gas tank comes off with two nuts and affords you plenty of room to fiddle with the wiring under the dash. Dash is on the right side of the gas tank.

 

[JB4310]

JC, Does the power go thru the Glow Indicator to the GP's and ground to engine, meaning that if the GI was open (burned out) the GP's would get no power? vis versa if the GI lights up then at least one GP is working completing the circuit to ground. or does the GI have it's own ground and glow independent of the plugs?
Why do both leads from the GI go to the switch (according to your schematic) term 17 and 19?

Ray, didn't mean to hijack your thread but my 1700 has been rough starting and I suspect maybe one glow plug is burned out. You didn't say whether your having trouble starting or just noticed the indicator not working.

 

[Hooked_on_HP]

The power goes through the indicater and grounds via the glowplugs. To check your glowplugs disconect the wire going to the glowplugs and the jumper from glowplug to glowplug. Take an ohmmeter and check from the center of the glowplug to ground. The resistance should be 1 ohm.
Bill

 

[Hooked_on_HP]

I was WRONG on on the ground for the indicator . It does go back through the ign. switch.
After further investigation I was not wrong. 12v comes from post 19 on the ign. switch goes through the glowplug indicator back to post 17 on the ign. switch where it connects with the wire going to the glowplugs . Post 17 does nothing. I wonder why they didn't just run the wire from the glowplugs to the indicator.

 

[JB4310]

The power goes through the indicater and grounds via the glowplugs. To check your glowplugs disconect the wire going to the glowplugs and the jumper from glowplug to glowplug. Take an ohmmeter and check from the center of the glowplug to ground. The resistance should be 1 ohm.
Bill

I do have a good dig multi meter but don't completely understand all its functions, Basically I understand how to read voltage and how to test for continuity. Since the GP is just a coil then if the wires are removed couldn't I just check for continuity from the term on the GP to ground? is the resistance of 1 ohm basically a measure of continuity?
I see that term 19 in JC's schematic looks like it could be a ground completing the indicator's circuit assuming that 17 is the hot feeding both the indicator and the GPs, is that normal to have a ground in a main ignition switch?

JB.

 

[RickB]

I was WRONG on on the ground for the indicator . It does go back through the ign. switch.
After further investigation I was not wrong. 12v comes from post 19 on the ign. switch goes through the glowplug indicator back to post 17 on the ign. switch where it connects with the wire going to the glowplugs . Post 17 does nothing. I wonder why they didn't just run the wire from the glowplugs to the indicator.

Post 17 supplies voltage directly to the glowplugs while cranking. The indicator coil is not powered while the start solenoid is engaged.

 

[Hooked_on_HP]

As usual Rick you are right. I just went out and checked and do have voltage on 17 while cranking.

 

[JB4310]

So does that mean during glow plug position on the switch that power is only going thru indicator from term 19 and using 17 just as a connection to the gps or is power going out of term 17 at the same time? I guess it couldn't (both sides of indicator would be hot).

I guess they did it like that to minimize power draw during starting (cutting out the indicator but still keeping the GPs hot).

So for the OP then if his indicator is not glowing for what ever reason, then his glow plugs are not heating. and also if both glow plugs were to burn open then the indicator wouldn't light?
I'm going out to check mine today, I have a better understanding now what to look for. I think!

 

[JC-jetro]

JC, Does the power go thru the Glow Indicator to the GP's and ground to engine, meaning that if the GI was open (burned out) the GP's would get no power?

John,

That is how the wiring diagram indicate. I have never verified it since I never had a problem with my glow plug. I'm not convinced if 17 directly powers the plug bypassing the 19. On the switch the key has a 12 o clock position and 10 am and 2 pm. there is only one position to the left 10 am and that is just for glow plug and the current need to go from 19 to 17 turning the heater red in time in which during this time the glow plug is warming up. the heater is just an indication of the time necessary.

Once the adequate time/heat is achieved then you turn the switch to 2 pm where the power is removed from the heater and starter comes solenoid gets picked up like Rick said. You will not be glow plugging if there is a term like that and start at the same time. it is same as if you have the light on on car and try to start the starting circuit kills the light in newer car before the starter runs.

JC,

 

[RickB]

John,

That is how the wiring diagram indicate. I have never verified it since I never had a problem with my glow plug. I'm not convinced if 17 directly powers the plug bypassing the 19. On the switch the key has a 12 o clock position and 10 am and 2 pm. there is only one position to the left 10 am and that is just for glow plug and the current need to go from 19 to 17 turning the heater red in time in which during this time the glow plug is warming up. the heater is just an indication of the time necessary.

Once the adequate time/heat is achieved then you turn the switch to 2 pm where the power is removed from the heater and starter comes solenoid gets picked up like Rick said. You will not be glow plugging if there is a term like that and start at the same time. it is same as if you have the light on on car and try to start the starting circuit kills the light in newer car before the starter runs.

JC,

The glowplugs are powered when the key switch is in the crank position as well as the preheat position. In the preheat position, terminal 17 is powered from the indicator coil. In the crank position, terminal 17 is powered internally from the key switch. Any time terminal 17 is powered, the glowplugs are as well.

A tractor with a failed open indicator coil can be preheated by holding the key in the crank position while leaving the shifter in gear or clutch pedal up (NSS open). After a normal preheat interval, shift to neutral or press the clutch, closing the NSS. The preheated engine will fire up as if it had been preheated normally.

 

[JB4310]

A tractor with a failed open indicator coil can be preheated by holding the key in the crank position while leaving the shifter in gear or clutch pedal up (NSS open). After a normal preheat interval, shift to neutral or press the clutch, closing the NSS. The preheated engine will fire up as if it had been preheated normally.

Wow Rick, that's a great trick to know, using the clutch safety to bypass a failed indicator using the crank position on key. Thanks.

Checked my GP's today and both are good, so I guess my hard starting is due to old age/high hours (2600+) Since I've never seen one I took them right out to test them and man they do get hot, that little coil thing in the dash is very mild compared to the glow plug, I envisioned a little coil similar to the indicator.

JB.

 

[JC-jetro]

The glowplugs are powered when the key switch is in the crank position as well as the preheat position. In the preheat position, terminal 17 is powered from the indicator coil. In the crank position, terminal 17 is powered internally from the key switch. Any time terminal 17 is powered, the glowplugs are as well.

A tractor with a failed open indicator coil can be preheated by holding the key in the crank position while leaving the shifter in gear or clutch pedal up (NSS open). After a normal preheat interval, shift to neutral or press the clutch, closing the NSS. The preheated engine will fire up as if it had been preheated normally.

Rick,

I'm sure that you're right. For the sake of satisfying my curiosity I'll check it next time I go to my place. What puzzles me is if you take a look at the pic below, When i turn the key to heat the current has to go thru terminal 19 as It heats the glow plug and the resistive element. Going thru 17 can for sure heat the glow plug but totally bypasses the 19 hence no indication. I'll put a test lamp between terminal 17 and ground and see if it light up when I crank.

JC,

 

[rayikeo2]

JC, I haven't had time to check it out yet so I got it started on a warmer day and moved it into a garage where I can use electricity to plug in the engine heater as a start aid. Do you have an engine heater plug in for your tractor? It works great if I plug it in for 30 min or so even in the dead of winter.
I will try the trick mentioned of by-passing the start aid using the start position of the ign switch. I would not have thought of doing that. Ray

 

[JC-jetro]

JC, I haven't had time to check it out yet so I got it started on a warmer day and moved it into a garage where I can use electricity to plug in the engine heater as a start aid. Do you have an engine heater plug in for your tractor? It works great if I plug it in for 30 min or so even in the dead of winter.
I will try the trick mentioned of by-passing the start aid using the start position of the ign switch. I would not have thought of doing that. Ray

Ray,

No I don't have a block heater. I have never used any assistance beyond 15 seconds of glow plugs operation to get her started. I suppose correct injection timing, spray pattern, fuel type, condition of valves intake and exhaust all play a role in quick starts. Maintaining high rate of compression leads to combustion of diesel so worn out rings could reduce compression as well leading to rough and hard starting. I have to qualify my statement also that my use in mainly in fair weather situation. I don't live on my property so have very little winter use unless I'm playing. I have started my tractor many times in occasional very frigid Kansas weather without issues.

JC,

PS. Just one thing to add, at start position your "starter is cranking". I think it is pretty bad idea to keep the starter running for 30 second or so just to get glow plug to heat up. I hate to burn my starter doing that. I'll take my sweet time and heat things up on pre-heat and let the starter run for 5 to 7 second to get the tractor started. I'll leave a little time each time I use the starter to give it a rest as well. starters are not very cheap. I'll check next time I'm there but,per Rick with the clutch up, clutch safety switch engaged and the key in start position you'll get no cranking but glow plug operation.

 

[rayikeo2]

JC, What position do you put the throttle lever in when starting cold? Half open or full throttle? I have been using 1/2 open and seems to flood sometimes and hit on 1 cyl for a few revolutions.

 

[JC-jetro]

JC, What position do you put the throttle lever in when starting cold? Half open or full throttle? I have been using 1/2 open and seems to flood sometimes and hit on 1 cyl for a few revolutions.

Ray it depend on how the throttle linkage is adjusted. I have adjusted mine in a manner where I can kill the engine by simply moving the lever all the way up without having to kill the engine with the brakes on and clutch let out like previous owner suggested to me. It takes me a a little less than the 1/4 turn to get it started around 1000-1200 rpm.


JC,

 

[rayikeo2]

You lost me with the 1/4 turning part. What are you turning? The throttle lever or something else? I saw the picts.