I have read all the post and answers about new jinma tractors that will not start in cold weather. My tractor will not start in 40 degree weather with out some trouble. I have installed a ford switch, I pulled all the glow plugs out they all read 2.4 ohms on the bench. I checked for voltage through the glow plug path and this is what I have found. I have 12.6 volts to the plug wire as long as it is unhooked from the plug buss bar. As soon as I hook it up to the bar the voltage drops to 3.0 vdc. Can you give any solutions ? Thanks Robby
SPIKER
Elite Member
Robby:
you did not say about if the glow plugs were installed at the time of the test where you got 3.0 volts across the buss bar when the switch was turned to the glow plug mode. if the plugs WERE installed then you are possably getting a too weak of signal too the plugs due to resistance in either the switch or the wires leading to/from switch to the buss bar. the next step could be a partly shorted buss bar too. you can measure the bus to battery "-" ohms (the reading numbers I belive are listed on johns web page.) but are pretty low, something like 1.2 or 1.8 ohms through the glow plgs bar and all 3 plugs to the block and then to the battery "-" there is also possability of having some grounding issues so remove all the battery cables and clean under them for paint rust or dirt and make sure they are tight. also connect an extra ground strap between the battery and the engine block if it is hooked to the "-" is hooked to the frame. anyhow I bleive there is a good bit of glow plug info on JOHNS page whicch is under the key sw3itch listing only up a page or two... under JINMA mods and tests or something like that.
MarkM
you did not say about if the glow plugs were installed at the time of the test where you got 3.0 volts across the buss bar when the switch was turned to the glow plug mode. if the plugs WERE installed then you are possably getting a too weak of signal too the plugs due to resistance in either the switch or the wires leading to/from switch to the buss bar. the next step could be a partly shorted buss bar too. you can measure the bus to battery "-" ohms (the reading numbers I belive are listed on johns web page.) but are pretty low, something like 1.2 or 1.8 ohms through the glow plgs bar and all 3 plugs to the block and then to the battery "-" there is also possability of having some grounding issues so remove all the battery cables and clean under them for paint rust or dirt and make sure they are tight. also connect an extra ground strap between the battery and the engine block if it is hooked to the "-" is hooked to the frame. anyhow I bleive there is a good bit of glow plug info on JOHNS page whicch is under the key sw3itch listing only up a page or two... under JINMA mods and tests or something like that.
MarkM
billbill1
Veteran Member
- Joined
- Oct 13, 2004
- Messages
- 1,207
- Location
- Lecompton, Kansas
- Tractor
- 2016 Mahindra 1533 Shuttle AgKing 2840 shuttle shift
The connections on my starter were painted and not getting good connection and the ground strap to ground was painted also. The problem was a bad starter as it turned out but several connections were bad.
greg_g
Super Member
- Joined
- Dec 18, 2003
- Messages
- 6,126
- Location
- Western Kentucky
- Tractor
- JD3720 Cab, 300X loader with 4-in-1 bucket
Dirty glow plugs don't ohm out well. They should be removed from the tractor, cleaned with solvent, and wire brushed before testing for resistance at room temp. Oh, and don't lose track of the little copper sealing washers. If you did all that and still got 2.4 ohms, the glow plugs are going bad - not getting hot enough.
Divide your 12.6v by 2.4 ohms, and you'll see they're only pulling 5.25 amps each. A good Jinma glow plug should pull at least 7 amps at room temp (colder than that, it will pull more). To do that, the glow plug resistance needs to be closer to 1.7 ohms at room temp.
And not getting all supply voltage to ground through the plugs,
likely accounts for the 3v reading at your bus bar.
The good news is that new Jinma glow plugs are cheap. I replaced a set of Y385 plugs a couple of years ago for under twenty bucks.
//greg//
Divide your 12.6v by 2.4 ohms, and you'll see they're only pulling 5.25 amps each. A good Jinma glow plug should pull at least 7 amps at room temp (colder than that, it will pull more). To do that, the glow plug resistance needs to be closer to 1.7 ohms at room temp.
And not getting all supply voltage to ground through the plugs,
likely accounts for the 3v reading at your bus bar.
The good news is that new Jinma glow plugs are cheap. I replaced a set of Y385 plugs a couple of years ago for under twenty bucks.
//greg//
I have a Farm Pro 2425 and had the same starter problems. I installed a Kats heater in the lower water hose, now i just plug it in for an hour or so before starting and it fires right off. I just think some of these engines are harder to start than others even when the plugs all work.
Billy
Billy
F100Panel
Silver Member
Based on the factory wire size alone I was convinced I was not getting enough power to the glow plugs on my 224. I went to the local Autozone & bought a $7, 30 amp relay meant for Fog/driving lights. They come with simple wiring diagrams.. I ran a fused #10/30 amp wire from my starter cable to the relay & #10 from the relay to the glows. I used the original power feed from the glows to power the relay & I noticed instant improvement. As I could not see the glow plug draw on the amp gauge anymore with this wiring configuration I added a little LED light to the dash to tell me when there was juice going to the glows... I also changed out the battery cables to American standard & she spun over better too..... Just my experience.....
Harrygoodwrench
Gold Member
F100Panel,
I did same modification as you. Its the only way to go in my opine. The relay provides the high current and the LED light tells you the glow plugs are getting current. Now there are some that would argue that now you can't use the amp gauge to tell amp flow. Thats kind of a mute arguement as if it starts well it doesn't matter what the amp reading is anyways and if you are having troubles starting then you will be checking the glow plug system in a more precise way than using the dash mounted gauge. Harry /forums/images/graemlins/grin.gif
I did same modification as you. Its the only way to go in my opine. The relay provides the high current and the LED light tells you the glow plugs are getting current. Now there are some that would argue that now you can't use the amp gauge to tell amp flow. Thats kind of a mute arguement as if it starts well it doesn't matter what the amp reading is anyways and if you are having troubles starting then you will be checking the glow plug system in a more precise way than using the dash mounted gauge. Harry /forums/images/graemlins/grin.gif
F100Panel
Silver Member
Thanks Harry... Whats the gauge on the factory glow plug power supply wire ? About #18 I'd guess...??? Ain't no way your gonna get a full 20 amps ( thats the average as they warm up after drawing 30 at the begining...) for 20 seconds before that wire heats up & resistance rises ( just like the glows..).....& power to the glow plugs drops. I'm kinda stunned Jinma still uses that gauge wire... /forums/images/graemlins/mad.gif
Harrygoodwrench
Gold Member
F100Panel,
I don't know what the exact gauge of the Jinma glow plug wiring is as its a metric dimesion. I would guess the cross directional diameter would be equilvant to maybe 16 AWG at best. 18 gauge obviously is smaller than 16 so I'm giving some here but even 16 gauge basically maxes at 25 amps before the current flow drops due to the resistance of the heat of the amperage flowing. Ampicity I believe its called according to my old college days.
Either way, the way we modified it is the way to go. Safer too, if you fuse it separately.
I don't know what the exact gauge of the Jinma glow plug wiring is as its a metric dimesion. I would guess the cross directional diameter would be equilvant to maybe 16 AWG at best. 18 gauge obviously is smaller than 16 so I'm giving some here but even 16 gauge basically maxes at 25 amps before the current flow drops due to the resistance of the heat of the amperage flowing. Ampicity I believe its called according to my old college days.
Either way, the way we modified it is the way to go. Safer too, if you fuse it separately.
