bad ignision when lamps are on

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infotfordnl
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First Name: Bert
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bad ignision when lamps are on

Post by infotfordnl » Wed Aug 21, 2019 4:19 pm

When I put my lights on my ignission gets weaker.
so far the engine doesnt turn properly.
Lights off engine turns normal.
when I clean the sparks it goes better but after a while the problem comes back.
maybe new sparkplugs?
does someone regonise this problem?
regards
Bert
Nice movie of this Model T: https://youtu.be/jD1QJBZasdY

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Henry K. Lee
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Re: bad ignision when lamps are on

Post by Henry K. Lee » Wed Aug 21, 2019 4:23 pm

Voltage drop, check for bad connections. Are you running on battery?

Try magneto with lights on.

Hope this Helps,

Hank

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JohnH
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Re: bad ignision when lamps are on

Post by JohnH » Wed Aug 21, 2019 8:01 pm

In my instance of this happening, it was because the battery was at the end of its life. With the generator charge rate at 5A, and the lights drawing 10A, the battery voltage would start to fall after about half an hour of driving. An analog volt meter will quickly track down the fault. If the battery is OK, then measuring the voltage at all the connections between the battery and coil box should find the problem.

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Topic author
infotfordnl
Posts: 84
Joined: Tue Jan 15, 2019 2:11 am
First Name: Bert
Last Name: van Amstel
* REQUIRED* Type and Year of Model Ts owned: Runabout pickup 1927
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Re: bad ignision when lamps are on

Post by infotfordnl » Thu Aug 22, 2019 3:56 am

Thanks John and Henry,
I will search now in the battery area, I have to say that it looks that the car start a bit more slow and that experiance fit with the battery idea.
I will charge the battery full up and test it again, the problem should be gone than for the moment.
If that is so I will put a new battery in the car.
Anny way I use my pickup every day when the weather is good.
I love driving in it.
Come back with the result
thanks
Bert
Nice movie of this Model T: https://youtu.be/jD1QJBZasdY

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Topic author
infotfordnl
Posts: 84
Joined: Tue Jan 15, 2019 2:11 am
First Name: Bert
Last Name: van Amstel
* REQUIRED* Type and Year of Model Ts owned: Runabout pickup 1927
Location: Netherlands
Board Member Since: 2018
Contact:

Re: bad ignision when lamps are on

Post by infotfordnl » Wed Jan 29, 2020 10:35 am

Time ago I start this topic for my problem what Is still not solved.
Do some test and measurements,
If my lamps are off I have 6.29 volt on the wire to the coilbox
If my lamps are on It fall down to 5.10 Volt
Is that normal? And If not what to do?
As far I can see the connections are not bad, ...
I have no idea what will be the correct thing to do
My T is an 1926
Hope someone can help me so I can use my T also when It is dark..
Bert
Nice movie of this Model T: https://youtu.be/jD1QJBZasdY


Norman Kling
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Re: bad ignision when lamps are on

Post by Norman Kling » Wed Jan 29, 2020 11:30 am

The Model T was made to run on magneto. The lights on a 26 would not affect the output of the magneto. If you are using a distributor, or other ignition run from the battery, the low battery would affect the spark. On an earlier T magneto lights might also affect the spark if you have a weak magneto. Two solutions to this problem if you are running on battery. One would be to raise the output of the generator to charge more. It would then charge up the battery when running during the daytime and lower it less at night. If you do a lot of night driving, you can install a voltage regulator in place of the cutout and set the charge rate higher to cover the output needed to run with the lights on and the regulator would lower the charge rate as the battery reaches full charge.
You are also right about an old battery. It will take a quick charge but will run down more rapidly as the battery loses ability to hold a full charge.

Before you do a lot of changes, first check all connections for corrosion. Especially those at the battery terminals and ground connection. Electricity takes the path of least resistance and if the lights have a good connection but the ignition has a poorer connection it could lower the voltage at the ignition. Likewise, a weak conductor from the starter switch to the terminal block and to the ignition switch, could lower the voltage to both. If all connections are good, then follow the above suggestions.
Norm

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Topic author
infotfordnl
Posts: 84
Joined: Tue Jan 15, 2019 2:11 am
First Name: Bert
Last Name: van Amstel
* REQUIRED* Type and Year of Model Ts owned: Runabout pickup 1927
Location: Netherlands
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Contact:

Re: bad ignision when lamps are on

Post by infotfordnl » Thu Jan 30, 2020 10:55 am

Thanks for your advise Norm,
If i connect the wire 3 who is coming from the battery to wire 5 or 6 (headlights) the problem is gone.. , could that say something,? So bypass the am meter and the switch
Bert
Nice movie of this Model T: https://youtu.be/jD1QJBZasdY


Norman Kling
Posts: 4069
Joined: Tue Jan 08, 2019 1:39 pm
First Name: Norman
Last Name: Kling
Location: Alpine California

Re: bad ignision when lamps are on

Post by Norman Kling » Thu Jan 30, 2020 10:59 am

Not likely the ammeter, but could be the switch.
Norm

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