25 hp jinma tractor starter drags

[Soundguy]

I've talked with you enough to know that you knew what you are talking about. i didn't think for a second it was anything more than a typo.

Soundguy

PS: I'm off to prep the old ford for a hayride!

 

[Amez]

Nope , I meant voltage drop. If the ampacity of the wire is exceeded , the draw will cause a voltage drop due to the resistance of the wire. If the total cross sectional area of the supply wire(s) is large enough there will be negligable voltage drop (across the wire) during operation (therefore close to 12 volts drop across the glow plug).Two wires should be fine (as long as the total cross sectional area of the supply conducter is increased). It saves having to remove the old wire from the existing loom.
I ran into the rust problem on a 2500 hp Ingersoll Rand cetrifugal compressor which had an internal oil heater which was run year round. It resulted in a very expensive repair. I have installed many heaters but because of this observation on the compressor have never used them more than nescessary on my own equipment.

Hopefully you meant amperage drop, otherwise you might do well to get somebody who understands DC to be looking over your shoulder. And that amperage spike is normal, you're energizing three very high resistance devices after all. Well over 20 amps on a very cold block. If you see reduced amperage draw - say less than 15a - now that would point to a problem. At a minimum you should remove that second 14ga wire AND the original, replace them both with one good section of 10AWG primary wire. Alternatively, leave the OE wire in place, install a glow plug relay. Use 10 gauge between the battery cable and the relay, and between the relay and the buss bar.

Rust. That's a new one. Common sense, actually. Why preheat an engine - if you're not actually intending to start it? I get the impression you may never have actually installed your own engine oil heater before. That last sentence of yours is pretty much lifted right outa the installation/operation instructions that came with mine.

 

[greg_g]

Nope , I meant voltage drop. .

I'd say you need to ask for a 2nd opinion. First, the anticipated max amperage draw is pushing the rated capacity of your additional 14ga wire (when bundled). And adding a second wire betwee the same two electrical points doesn't reduce path resistance, it increases it. It's not much different than using 12 feet of wire, where only 6 are actually needed. As you've already stated, increased resistance results in decreased voltage. Given that the glow plugs resistance hasn't changed, delivering less voltage to them equates to delivering less amperage. Less amperage, they don't get hot enough to do their job.

That's assuming both wires are the same diameter and length. I think the OE wire is 12ga primary. 14ga presents more resistance per foot than 12ga. Now remember than electricity takes the path of least resistance. I'd say there's a chance that your second wire is even seeing a meaningful percent of the load, even if "sharing" made sense.

My recommendation remains to pull both those skinny wires outa there and replace them with one length of 10AWG primary wire. Or go the relay route, your choice.

//greg//

 

[Amez]

Adding a second wire between two points decreases path resistance. This can easily be measured with an ohmmeter.You may be confusing parallel circuits with series circuits. Adding a second wire between two points (parallel) in effect increases conductor diameter which allows more current flow.(its just like a fatter wire). As I said before , this can easily be demonstratad with an ohmmeter / ammeter.(After adding a second wire I actually measured increased current through the circuit)
By measuring the voltage drop across the supply wire you can calculate the resistance of the wire.This useful (basic) diagnostic procedure allows you to see if the resistance of the wire is causing a significant drop in circuit current without actually measuring the current (requiring wire disconnection or an amp clamp)
Simply put : the voltage drop of this complete circuit is 12 volts.The resistance of the glow plugs is constant for a given temperature (it increases as the glow plug heats up).
V=I x (resistance of wire + resistance of glow plugs)
The higher the resistance of the wire( deduced from voltage drop) , the less current going through the circuit (and glow plugs).
Cross sectional area of 12 gauge = 3.31 mm2
Cross sectional area of 14 gauge = 2.08 mm2
Cross sectional area of 10 gauge = 5.26 mm2
Cross sectional area of 12 ga +14 ga (in parallel) = 5.39 mm2 (larger than 10ga)
The three glow plugs are in parallel so the total circuit resistance is lower (one third) than it would be for one glow plug.(1/R=1/R1+1/R2+1/R3.....1/Rn).This has no bearing on the supply wire resistance however.
As for a second opinion I believe Georg Ohm will back me up.
Having said all that I do agree that the tidiest solution would be a single higher gauge wire from the switch to the buss bar and possibly from the battery to the switch , all neatly tucked inside the wire sheath.

 

[GuglioLS]

Adding a second wire between two points decreases path resistance........
........As for a second opinion I believe Georg Ohm will back me up.

Hey Amez Georg Ohm here Yes he will back you up - to a point, your thinking about the total cross sectional area is OK, IF the wire is one strand all in contact with each other. The smaller 14 ga wire will carry less current by nature / more ohms per foot vs the larger 12 ga wire. But with this small amount of current ~ 30 amps your OK.

To some degree everyone is right and wrong---

Try this little experiment (In theory only) - take a 6 ga wire and a 16 ga wire in parallel, each exactly the same length, let's say about 10 feet long, short them out across a fully charged 12 volt 900 CCA battery - which one is going to vaporize first? Fortunately that's not what Amez is doing.

You guys are getting all worked up over what? - two pieces of wire that are maybe 4 or 5 feet long at most? Give me a break.

Somehow I don't think the small amount of current running to your glow plugs through those two very short wires you got running in parallel are going to melt down and burn up your tractor. Amez I think your point is you are correct that the voltage drop across the total length of the two wires in parallel is less, hence more power in watts to the glow plugs and less power lost to resistance in the single 14 ga wire.

Amez, your 12 & 14 ga wires running in parallel are working, right? and has not burned up?

Larry

 

[greg_g]

Having said all that I do agree that the tidiest solution would be a single higher gauge wire from the switch to the buss bar and possibly from the battery to the switch , all neatly tucked inside the wire sheath.

Thanks for that anyway. In my world, efficient is more important than neat. Having both woud be a relative luxury.

If you use 10ga primary wire between the starter's battery post and a cheap NAPA relay

you won't need to change out the wire back to the keyswitch. It's only needed to engage the relay. Then run a 2nd piece of 10ga between the relay and the glow plug buss bar. If you want your glow plugs to remain energized while the starter is cranking, run a 2nd length of 10ga between the solenoid output post and the relay.

What I described above is one of two relays I added to my Y485. With no compression release, the electrical system needs all the help it can get during cold starts. The second relay is on my starter motor. Same principal; OE wire from keyswitch to NAPA relay, 10ga in and out of the relay. Both relays, wire, connectors, heat shrink came to ~25 bucks. Assembly and installation time was under two hours (heat shrinking the wire connectors was time-consuming). Oh, and to increase (charging) voltage returned to the battery - I added one final length of 10ga, between the alternator output and the battery cable post on the starter motor.

//greg//

 

[Amez]

I think I'll add the wire from the solenoid to energize the glow plugs while cranking.Any problems with blowing the 30A fuse with boyh the starter and glow plugs energized?

Thanks for that anyway. In my world, efficient is more important than neat. Having both woud be a relative luxury.

If you use 10ga primary wire between the starter's battery post and a cheap NAPA relay

you won't need to change out the wire back to the keyswitch. It's only needed to engage the relay. Then run a 2nd piece of 10ga between the relay and the glow plug buss bar. If you want your glow plugs to remain energized while the starter is cranking, run a 2nd length of 10ga between the solenoid output post and the relay.

What I described above is one of two relays I added to my Y485. With no compression release, the electrical system needs all the help it can get during cold starts. The second relay is on my starter motor. Same principal; OE wire from keyswitch to NAPA relay, 10ga in and out of the relay. Both relays, wire, connectors, heat shrink came to ~25 bucks. Assembly and installation time was under two hours (heat shrinking the wire connectors was time-consuming). Oh, and to increase (charging) voltage returned to the battery - I added one final length of 10ga, between the alternator output and the battery cable post on the starter motor.

//greg//

 

[greg_g]

Any problems with blowing the 30A fuse with boyh the starter and glow plugs energized?

None. I did this before on a JM254 with a Ford cold start keyswitch. I'd glow with the switch in spring loaded HEAT position. Then I'd turn the key to the spring loaded START position. The way the Ford switch is configured (and when wired in properly) voltage is supplied to both the starter solenoid AND the glowplug buss bar when the key is the START position.The whole time I owned those two Jinmas, I never once had to replace a system fuse. That said, the coldest I've ever started up here in KY was -22C.

And the relay configuration that I described above, almost completely bypasses the fuse panel. The only fused current draw would be the insignificant amount required between the keyswitch and the relay(s).

//greg//

 

[Soundguy]

I think I'll add the wire from the solenoid to energize the glow plugs while cranking.Any problems with blowing the 30A fuse with boyh the starter and glow plugs energized?

Yer starter is not fed by the fuse....

Soundguy

 

[Amez]

I haven't looked at the diagram , I assumed it was the starter solenoid which was fused.

Yer starter is not fed by the fuse....

Soundguy