TEA-20 starting and charging

[Matt Higgins]

Hi all, hope you can offer a bit of help. My Dad and I have rebuilt a wrecked TEA-20 up over the last few years, and we"re just about there save for a couple of niggles. The tractor is a 6 volt version, and I"ve cleaned and cleaned all the connectors up, but still get a very sluggish turn over when trying to start it, almost as though the battery is short on power. We"ve had it tested and it looked ok. The red ignition light was on constantly, so we bought a new control box, and that fixed the light (well it went off!), but how do I test that the battery is being charged?

More oddly, the starter stick always worked until last week - now nothing. We"ve a new startter solendiod, and the tractor turns over if you short it. Not ideal. Is the linkage adjustable?

Sorry for the long post, but we"re that close, I"d hate to have to bodge fixes with starter buttons and 12v batteries!

Cheers, Matt

 

[Jeff-oh]

You can adjust the starter linkage. The sluggish starting could be worsening connections in the starter switch. Perhaps a new switch.

The 4 cap screws on the switch housing can be loosened and the starter pushed fwd. to apply more pressure on the switch when the stick is engaged. See cartoon.

 

[Matt Higgins]

Brilliant, thanks Jeff, that's really useful - the switch is only a few months old, and when I took it back off to check, it all seemed to operate ok, so I suspect that what you've described about it is the problem, and I need to move the starter forward to make it more sensitive.

Am going over at the weekend, so will definately give this a try.

Thanks again, Matt

 

[Klaus]

If you have a Voltmeter you should be able to measure something like 7 volts across the battery if the generator is working properly.
Also the TEA has a blanked off hole in the dash. Pop it out, and you can install a ammeter. That will help you too.
Klaus Frøslev.

 

[Matt Higgins]

Thanks Klaus - I have a spare ammenter in a box somewhere - are they voltage specific, or will any one do?

I"ve seen a wiring diagram with an ammeter in, so I"ll review and have a think about it on Sunday

Thanks for replying, Matt

 

[phil(va)]

Make sure you are using large battery cables, not the smaller cables for 12 volts. Your cables should be #1 or #0 ideally, not #4 or #6 as for most cars. Get a longer ground cable and connect it to a bolt on the bellhousing for better ground than the typical dash connection. Others have told you good info, so I won't duplicate that.

 

[Klaus]

Hi Matt.
No, they are not voltage specific. So you should be able to hook it up quite easily.
Klaus

 

[Matt Higgins]

Excellent, thanks Klaus, found the diagram in question and it appears that you just connect it in line with the wire from the A post of the control box to the starter switch, so as long as I get them the right way round, even I should be able to manage that!!

 

[Matt Higgins]

Thanks Phil - I believe we're using the ones that were on the tractor, but it's certainly something I will check on. Are those gauges of wire US, or will they be the same in the UK?

Ta, Matt

 

[Jeff-oh]

It does not matter though the readout will be half that of a 12 volt system....

I= V/R Thus since: 6V is 1/2 of 12V current will be 1/2 also.

I = 12V/R => 1/2 I = 1/2 (12V)/R => 1/2 I = 6V/R

Jeff

Interesting I know... Just means needle on the gauge will swing only half the arc as it would on a 12 volt system.

 

[Matt Higgins]

(quoted from post at 19:46:35 02/25/09) It does not matter though the readout will be half that of a 12 volt system....

I= V/R Thus since: 6V is 1/2 of 12V current will be 1/2 also.

I = 12V/R => 1/2 I = 1/2 (12V)/R => 1/2 I = 6V/R

Jeff

Interesting I know... Just means needle on the gauge will swing only half the arc as it would on a 12 volt system.

I understand the last bit! Thanks for the help, Matt

 

[John (UK)]

To test if the battery is being charged, remove one of the battery cables when the engine is running about 1/3rd throttle, it should keep running on the out put of the Generator.
The fact that you starter switch does not work now could also be the problem with your starter as well,the adjustment for the switch is only small, slacken off the four small screws th fix the switch to the top of the clutch housing and slide it forward toward the engine and then tighten them up again, that will increase the pressure on the switch contacts, if you short it out and it works then the switch needs adjusting or replacing. Make sure that the Ground lead is moved from the back of the dash panel to one of the bolts close to the Starter, the panel will be insulated with rust by now and not making a good contact. The battery should be fitted Positive to ground unless you have a Alternator.. If you still have problems, email me and tell me what is happening...John
[email protected]

 

[Matt Higgins]

Thanks John - will have a go at those points on Sunday. We've already moved the earth off the dash, but the only place it would reach was one of the fuel tank bolts. If I end up making a longer cable as they're a) old or b) the wrong gauge, I'll make it longer. I've seen some that bolt on to the oil filler, so that's where I was aiming.

I'll be annoyed if it's the switch as it's relatively new (in months, rather than years). That said, it was a modern copy off ebay, so maybe it was a waste of money.....

Thanks for your kind offer, I'll mail you after the week (and update this thread with what worked and what didn't!!).

Regards, Matt

 

[rvirgil_KS]

The calculations of Ohms law relative to 6 and 12 volts is correct.

However, as I understand it, in a system with 6 volt generator charging a 6 volt battery and another system with 12 volt generator charging a 12 volt battery, both systems can charge at a rate of 0 (battery full charge) up to the rated output of the generator (10 to 20 amps)with low battery charge. At the same charge rate the ammeter would read the same whether 6 or 12 volt system.