Glow pllug wiring

[Reg]

I have to admit that I have a bit of a problem with this too. If you lift the bus feed, then you have an open circuit from the key switch on. Ideally, you should then have close to battery voltage at that point. If you had ~8 volts with the wire connected to the glow plugs, that I would expect. However, you're getting that voltage in an open circuit. Therefore, you have to be getting voltage drops from the battery to the key switch because of other branch circuits loading the OE harness to the switch. Imagine what the glow plugs must get when they are hooked up! That system does need help.

I see you have understanding of current flow and voltage drop.
Welcome.
(-:

 

[greg_g]

. If you had ~8 volts with the wire connected to the glow plugs, that I would expect.

No. Once again, I lifted the feed wire from the buss bar - then measured voltage between the feed wire and the negative post on the battery. There was 12.2v between battery posts, but only 8.7v between the feed wire and the negative battery post. The poor quality harness and cheap keyswitch were unquestionably loading the OE circuit down !

So rather than rewire the entire tractor to Mr Ohm's standards AND replace the keyswitch, I elected to bypass the voltage bottleneck to this critical circuit - with a $13 relay an $1 worth of 10ga primary wire. Now the 12.2v present at the battery, is delivered without loss to the buss bar. I used the very same approach to compensate for low switch voltage arriving at the starter solenoid. Like I said, this voltage loss issue is fairly common on the pre-EPA YangDong Y80 and Y85 series engines equipped with glow plugs and the QD100C3 starter.

Now can we PLEASE get back to discussing the starter issue that Valley started this thread about in the first place ??!!

//greg//

 

[quicksandfarmer]

Now can we PLEASE get back to discussing the starter issue that Valley started this thread about in the first place ??!!

//greg//

Don't disconnect anything. Have an assistant turn the key to the glow plugs position while you measure the voltage between the glow plug bar and the engine block, the glow plug bar and the positive battery terminal, the engine block and the negative battery terminal, and across the battery. All measurements must be done with the glow plugs on.

If:
* the voltage across the battery is less than 12v, your battery needs recharging or replacing.
* there is voltage between the engine block and the negative terminal you need to improve the ground.
* there is voltage drop between the glow plugs and the positive terminal you need to install a relay.
* there is zero voltage between the glow plug and ground you need to check the fuse and then trace back to the switch and find the open circuit.
* the voltage between the glow plugs and engine is 12V, verify on your dashboard ammeter that 30+ amps are flowing. If so, the glow plugs are fine. Otherwise, you need to investigate the plugs themselves.

There could be more than one issue, so once you have addressed one problem you need to keep repeating the test until all of the issues are taken care of.

For these tests a cheap voltmeter from Home Depot or Harbor Freight will suffice.

 

[Turbo]

No. Once again, I lifted the feed wire from the buss bar - then measured voltage between the feed wire and the negative post on the battery. There was 12.2v between battery posts, but only 8.7v between the feed wire and the negative battery post. The poor quality harness and cheap keyswitch were unquestionably loading the OE circuit down !

So rather than rewire the entire tractor to Mr Ohm's standards AND replace the keyswitch, I elected to bypass the voltage bottleneck to this critical circuit - with a $13 relay an $1 worth of 10ga primary wire. Now the 12.2v present at the battery, is delivered without loss to the buss bar. I used the very same approach to compensate for low switch voltage arriving at the starter solenoid. Like I said, this voltage loss issue is fairly common on the pre-EPA YangDong Y80 and Y85 series engines equipped with glow plugs and the QD100C3 starter.

Now can we PLEASE get back to discussing the starter issue that Valley started this thread about in the first place ??!!

//greg//

I must agree with you Graig on your relay repair, removing your wire from the buss bar and you only got 8 or so volts when exciting the glow plug wire, then your key switch is burned to a point of poor contact. and it's not a bad mode for saving the key switch. although IF the switch is rated a 30 amp, the mode may not be necessary, but good insurance.

back to the problem with his starting.

Testing:
With my system I performed the following test with a volt ohm meter

my battery 12.7 volts

Glow plug (GP) wire removed 12.7 volts key GP on

1 GP hook up to wire and GP key turn on 10.50 volts 2.2 volt draw (load)

2 GP hook up 8.84 volts 3.8 v draw

3 GP hook up was a jumper wire directed from the battery 7.66 volts 5.0 v draw, it made no difference which wire was used.

Ohm's readings
__E__
...IxR

................................................E / R = I
1 GP I had a reading of .8 ohm's 12.70/.8 = 15.87 amps
it's safe to say that the glow plug is in 180 to 210 watt range.

3 GP the reading was .5 ohm's 12.70/.5 = 25.40 amps

This is going to show total draw on the battery this will include you alternator stator field, and gages that become active when the key is turned on.
after see this it wouldn't take much to push it past the 30 amp fuse protection.
so I put everything on and tried it, and the 30a main fuse blow after 3 sec. time. now I not going to blame the wiring for it's failing but more on the load I put on the system.
as far as a relay goes it will provide protection from the key, but will add more load to the system, it maybe a small load but the magnetic coil still draws one. the out come to the Glow Plugs will be the same draw.

So how does this solve his problem?

If it has 12 volt going to the wire when removes and test it, key is fine.
when connected and blows the fuse then he has a shorted Glow plug.
if he doesn't have much of a voltage draw on the bar then he has a corrosion problem, and contact need cleaning.
remove the bar and and test each GP for .8 ohm's use the 200 setting on the meter, if it read "0" then it's shorted and needs to be replaced.

 

[valley]

I just happened by and saw you have been cutting up touches about the Glow plug problem.
Last year I cleaned and replaced the GPs. I replaced them still no go. All contacts were cleaned. I don't remember cleaning the contact at the key. I may or may not have got into the GP hole and poked around to break the carbon build up, I think I would have.
The addition of an electric thumper switch sounds like a way to go.
I could check with a jumper and alligator clips but removing the clips also would remove finger prints. [from the fingers]
We have been very busy or would have already applied the fix greg mentioned.

I do appreciate the thinking and pulling on the subject, it made for some good reading.

 

[valley]

Greg, if you're still around, guess what, I bought a relay today. Little over 8 years have passed. I'll try to get back here more often.

Richard

 

[Bob Rooks]

Greg, if you're still around, guess what, I bought a relay today. Little over 8 years have passed. I'll try to get back here more often.

Richard

Haven't noticed Greg around for awhile. Hope he's ok.

 

[valley]

Yes, I noticed that when I logged in, and hope the same.

 

[zonta223]

Yep been about 7 months since his last show on here

 

[valley]

I installed that relay, it's still cold enough to see it work.

I noticed Greg hadn't been around when I came by last. God willing there's no problem.

Zonta, Might get some rain Wednesday and Thursday.