Bn-4 heater step by step

[baseballfreak20]

Yeh. i tested it just like the white wire but with the green wire and I got nothing after spinning it a hundred times. I noticed by some posts that some said they heard the fule pump clicking. I hear it clicking nice when I took it off and added direct power to it. But I hear nothing when reinstallled. Can I get to the second set of points thru the first or do I have to take the whole heater apart?
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[man130]

You have to open heater up .ON the opposite side of fan housing from plasic red fan is a cast smaller fan held on to shaft with a set screw,take that off ,then the cap will be right there 1 or 2 screws and bam theirs your" pump" points ,you can check them easy now ,I would jus clean them up with some lite emory cloth or similar ,hopefully that should do it

[baseballfreak20]

I thought I would be writing back saying that I got it but not yet. I did find the other set of points and they were corroded together. I cleaned them up and think they're good BUT the capacitor (i think that's what it is) is "opened" up. Is it supposed to be? Its a WIMA Durolit. Maybe I'm looking tooo deep itno this.
I'm nearing my threashold on this but certainly appreciate all the help.
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We become immune to what we tolerate

Nobody is ever useless. They can always be used as a Bad Example!

[man130]

Well that all I can help,I know what your talking about ,I called it a condenser only cause that what you call it in a distributor. I'm not sure exactly what it does.So dont know how to fix it ,only thing I can think of is to replace it with a ignition condenser from distributor,but I'd check with somebody on this.Did you at least check it with positive source wire,light or voltmeter ,to check if it still interupts ground ,I'd say if it does put it back together and leave it alone .

[baseballfreak20]

FINALLY!!!!!!!!!after tearing it all the way down to what is now known as a capacitor, replacing it and resetting the points, it all works. Thanks to all for the help. I was at my end with it but after spending so much time and learning, I figured I can't let someone else fix it. THANKS!
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We become immune to what we tolerate

Nobody is ever useless. They can always be used as a Bad Example!

[man130]

congrats,where did you get the capacitor? Is it special for the bn4 or generic?

[baseballfreak20]

Radio Shack. 12v470UF. $1.81
4 days of labor and $2 worht of parts. You guys were right...toasty! Thanks
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We become immune to what we tolerate

Nobody is ever useless. They can always be used as a Bad Example!

[doublecanister]

hey Baseballfreak20;

so a capacator fixed it? and it cost 1.81 ? That's too cool

a $1.81 part fixed a type 181....what a coincendence.

And Man130 you are right, I think the part called a condenser (like in a distruibutor ) is a capacator, but I'm not %100 sure, anyways....

I may have the exact same problem, stay tuned I'll test and let yall know
Good Job BaseBallFreak, got any pictures of your adventure?

Man130 you're going to be the heater guru if this success keeps up.

T.
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****************************************
2020 - Mustang Eco Boost [High Performance]
1973 - Thing
1966 - Mustang GT- Fastback
1951 - Ford F1 pickup Flathead V8

[baseballfreak20]

Believe me. A couple of days ago after taking the heater apart and putting it back together and testing it about 5-6 times with the same results, I was miserable. Honestly, I almost gave up. I did all the checking and testing and still couldn't get it to work. I do know that the points were corroded together and that the capacitor was opened up. I polished up and reset the points and soldered a new capacitor in it. Then and only then did it work. Funny, as soon as I turned the heater on and heard the fuel pump for the first time, I knew it better work. It did take a couple of minutes for the fuel line to fill up and get to the heater. Then, "POOF", heat. Again, thank you to you guys that responded to me and guided me thru it!
_________________
We become immune to what we tolerate

Nobody is ever useless. They can always be used as a Bad Example!

[uberautowerks]

A condenser is a capacitor. It's job is to prevent or reduce arcing across the points when they open.
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[man130]

Thanks Eric ,I've wondered what it did ,thought it stored power or somthing ,now I know.

[tallman206]

A "condenser" is the old-tyme electronics world name for a capacitor.
Same meaning for both words. Seems like the auto industry stuck with the name condenser when the electronics world moved forward and started calling it a capacitor.

Its purpose here and also in the points type ignition circuit is two-fold.
It does store energy, and it does protect the points.
If you think about it, an ignition coil and the electromagnetic coil of the fuel pump are both large inductors (magnetic coils). When the points are closed, a current flows through the coil (or fuel pump windings) and through the points to ground. The capacitor is electrically wired 'across the points' which means in parallel to the points. When the points open, the intense energy stored in the coil tries to go somewhere. Without the condenser in place, the points would take a beating and try to arc over as the coil discharges its stored energy. The points cannot be made to last very long under this condition, so they will eventally burn and or weld together. However, if you have the condenser installed, it acts as sort of a shock absorber for the stored energy from the coil. When the points open, the energy from the coil is diverted to the condenser that is in parallel to the points, and the condenser tries to charge itself up while the coil discharges. This protects the points by giving a nice cushy place for the current to go (into the condenser).

The capacity of this condenser does not have to be great, probably in the 0,33 to 1.0 microfarad range, but the voltage rating should be relativly high, like 500 volts or so, as the discharge voltage of the coils is rather high. It is probably a better choice to use a non-polarized condenser rather than an electrolytic polarized condenser. If you have the wrong condenser values, or if it doesn't work, the points will eventually burn and either weld closed or go open.

This concludes your mini electronics lesson for the day....

Jerry

[man130]

Jerry ,I think your that mad scientist from "back to the future".Thanks for the lesson . Just to clarify ,if a heater one goes bad I could just order one for the distributor and values would be ok .Because I would'nt trust the guy at radio shack to get me right one.

[tallman206]

Yes, an ignition one will probably be the best substitution choice, if you can get it installed inside the heater...

[Captain Spalding]

[tallman206]

Hey Cap!

(So 'splain me sumthin please. Two part question. The points want to arc when they open, and the condenser stymies that. I get it. Do the points want to arc as they close also? And does the condenser act in the same capacity there too? Does the condenser rob charge from the spark plugs? If not, why? Or if it does, why isn't it a factor? )

The points don't really want to arc when they close. Think about it. When the points are open and the circuit is quiet, there is no current flowing in the circuit. There is no high voltage stored anywhere that can cause the points to try and arc over as they are closing, as this just won't happen with only 12 volts across the points. There is 12V across the condenser as well, but the condenser is such a low storage value (0.33uf or so) that not much 12V energy is stored in the condenser. When the points finally close, the condenser will dump its little bit of stored energy to ground through the points, which is not much, and also the coil (or pump windings) will start to store energy. The real problem comes when the points open, as when this happens, the coil drops in voltage quickly, and produces a high energy output to the spark plugs, and also a high voltage spike back to the points, which causes the damage.

Most damage to relays, switches, points, any type of electrical contacts, usually occurs when the contacts open, as this is when arcing tries to occur. Contacts (or points) are usually properly designed for their application to adequately handle the closed circuit current with no problem. They need help from a condenser when the contact points open.

The condenser doesn't actually rob power from the plugs. It actually enhances the coil performance. You know from experience that you can get poor performing engine if the condenser goes bad. When the points open, for the coil to properly do its job, the energy stored in the primary winding of the coil must go somewhere. Without the condenser, this energy will attempt to create an arc weld across the points that are opening, although not very sucessfully. If the condenser is installed, the primary winding energy of the coil has a nice place to go - into the condenser, to discharge the coil, which makes its secondary windings produce a big fat spark. The coil is actually a step up transformer, so when the magnetic field of the primary winding collapses through the condenser, a magnetic field is induced into the secondary windings at a higher voltage, which is used to produce the spark output ..

Lesson two of your daily electronics course is now concluded...
Jerry

[tallman206]

And for your homework review, and if you think I am pulling your leg, here is some very light reading on the Kettering Ignition System (which is what we use).
http://83.70.181.166/moodlecp/mod/resource/view.php?id=185

And if you are wondering why we hijacked the BN4 discussion with ignition theory, it is because the principles are very similar - contact points controlling an electromagnet device (the fuel pump or the ignition coil for the heater spark plug).

Happy reading tonight, and there will be a test somewhere in your future, you can bet on it...

Jerry

[baseballfreak20]

FYI: the Radio Shack guy/kid actually gave me that very close class which I trusted him in what he said. Also, at first I installed the 1000 volt capaciator but couldn't install the cap back on. So, I went back and got the 470 volt. It's actually a tad larger than the originally one but it fit. He seemed to think that the original one was probably around 400 but that was just based upon the size and the "400" on it. However, he just guessed as to the size.
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We become immune to what we tolerate

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[humbuds]

baseballfreak20; Is there a chance you could post the stock or model # of the capacitor from radio shack that worked for you? I'm not finding one in the catalog with your stated specifications. My existing capacitor is showing no resistance (short to ground). I live rurally and buzzing down to Radio Shack is something I would like to avoid if possible, mail order works best for me. thanks.

[baseballfreak20]

Radio Shack #272-1018 Electrolytic Capacitor.

Now if I can get anybody to respond to me needed the heater duct I might be able to get the dash back together.
_________________
We become immune to what we tolerate

Nobody is ever useless. They can always be used as a Bad Example!