Jinma 284 electrical schematic (2005, integrated instrunment panel)

RonMar · May 29, 2011

In troubleshooting my tach failure (bad sensor, only putting out .5V signal instead of the nearly 5V signal the tach needs to operate) I pulled my cowling and also did some wire cleanup. This gave me the chance to finally finish the updated electrical schematic I started several years ago, which I have attached here.

Enjoy!

Bob Rooks · May 29, 2011

Very nice :thumbsup: Is this an as-built or does it include your mods too?

RonMar · May 29, 2011

Bob Rooks said:
Very nice :thumbsup: Is this an as-built or does it include your mods too?

As-built... I havn't done any electrical mods, this is from the factory wiring...

I am about to modify the glow plug wiring though. From the factory, the wire leaving the key heater post is maybe 14GA. It goes to the fuse block multi pin connector, to the 30A heater fuse, and back to the multipin connector, then back around the tank, past the key and around the left sde and out to the front of the glow plug connecting bar. I discovered a problem at the multi connector, and actually get a little smoke off the wire between the fuse and multi connector when I key the glowplugs. It is a poor crimp, and marginal wire size for 30A of glowplug current. Since I do not have the necessary multi pin spade connectors or fuse block spades to repair it properly, I am going to disconnect it at the key and glowplugs, and run a 10GA wire with inline blade fuse direct from the heater post to the rear of the glowplug connector bar. Appropriate wire gauge and less than half the original wire length from source to load... Ideally Jinma should have put a HD relay at the fuseblock for this like they did for the horn...

greg_g · May 30, 2011

Less labor intensive method is to mount a cheap Ford-type starter relay under the hood. Disconnect the OE wire from the glow plug buss bar and put it on the relay S post. Then run your 10ga from one of the larger relay terminals to the buss bar. Use another piece of 10ga to connect the 2nd relay terminal to your power source. If you don't have a Ford type keyswitch, there's also a way to wire the relay source so that the glow plugs will heat when the starter is cranking too.

//greg//

studor · May 30, 2011

Thanks for the diagram Ron. A couple of winters ago I replaced the glow plug wiring by running a 10 guage wire with an inline fuse from the ignition switch to the glow plug bar. I simply taped off the other wires since it was winter and I do not like to work in the cold! Has worked fine since

RonMar · May 30, 2011

studor said:
Thanks for the diagram Ron. A couple of winters ago I replaced the glow plug wiring by running a 10 guage wire with an inline fuse from the ignition switch to the glow plug bar. I simply taped off the other wires since it was winter and I do not like to work in the cold! Has worked fine since

That is exactly what I did this morning, It is all back together now, just waiting for my tach sensor...

Bob Rooks · May 30, 2011

Personally, I think you are asking for early key switch failure by running relatively high amperage through it. I would certainly opt for Greg's idea for using a relay. :thumbsup:

Rich Waugh · May 30, 2011

My solution is even easier - disconnect the glow plugs entirely. Might not be so successful for those who don't live in the tropics, though.

I think relays are great things for switching high loads. I use them on cars, tractors and machines. For the most part they're relatively inexpensive and easy to install. In some cases they almost pay for themselves in savings n heavier gauge wire and switches that die an early death from arcing contacts.

RonMar · May 31, 2011

Well thru the key is how it came from the factory, and it has been working without issue for 6 years now...

Bob Rooks · May 31, 2011

RonMar said:
Well thru the key is how it came from the factory, and it has been working without issue for 6 years now...

Excellent! But we all know about "factory" wiring design. :laughing:

greg_g · May 31, 2011

RonMar said:
Well thru the key is how it came from the factory, and it has been working without issue for 6 years now...

Yes, but the real question is "has it been working well?". The Y85 series engines are notoriously hard starters when cold. That's well documented. Out of sheer principle I added both a starter relay and a glow plug relay. Colds starting aggravation became a thing of the past - and extend the life of the OE keyswitch considerably.

//greg//

studor · May 31, 2011

I bet those matching belt and suspender outfits are hard to find

--just joshin

RonMar · May 31, 2011

greg_g said:
Yes, but the real question is "has it been working well?". The Y85 series engines are notoriously hard starters when cold. That's well documented. Out of sheer principle I added both a starter relay and a glow plug relay. Colds starting aggravation became a thing of the past - and extend the life of the OE keyswitch considerably.

//greg//

Mine has always started fine in the winter, even with the bad connection I found in the glow plug circuit during this evolution. In fact, I am still running the original chinese battery

I did add a 1KW tank type engine pre-heater last year to make the real cold starts a little less hard on the machine... Not that it gets especially cold here...

All good food for thought!

mikesheirich · Mar 11, 2012

RonMar said:
In troubleshooting my tach failure (bad sensor, only putting out .5V signal instead of the nearly 5V signal the tach needs to operate) I pulled my cowling and also did some wire cleanup. This gave me the chance to finally finish the updated electrical schematic I started several years ago, which I have attached here.

Enjoy!

Ron,
Nice work. It will help out a lot of owners...Mike

Trains1938 · Mar 5, 2019

Hi greg I am new to tractor stuff, could you or will put a diagram of how to do the thing you did. I am not a electrician or a mechanic. It sounds like a good idea but I am visual person so diagram would help a lot. It seems to me the wire from start switch should go to s terminal. What am I missing?