BN4 Heater Fuel Pump Electrical Issue

[ZacharyRitter]

I have a BN4 gas heater and the fan will cut on, the plug will get warm but the fuel pump is not getting electricity to the pump. I have disassembled the heater and cleaned the points in the fan motor for the fuel pump and checked the condenser with an ohm meter and getting reading of 3.92 ohms through the points. The fuel pump works fine if pulsing via battery direct. I am not sure what and how to check next.

[Wildthings]

As a guess if you are getting ~4 ohms across the points you have found your problem.

[77kafer]

Have you watched the video? http://www.thesamba.com/vw/forum/viewtopic.php?t=642527
_________________
Supposed to be 77käfer, but there are no umlauts on an american keyboard

Overheard on 27 June 07, one lady to another when they saw my Harli in a parking lot at West Point, "maybe he found it on the clearance aisle at the Volkswagen dealer"

[ZacharyRitter]

I have watched this video, it is a great start and a great overview. He briefly touched on the parts of the points. I just found out about the 2nd set of points on the other side of the fan. The ones I set were closets to the red fan (points closes every revolution of the fan). All other switches, relays, breakers seem to be operational. I will check the 2nd set of points for issues. Any thoughts? I am a newbie and need a little more direction.

[Captain Spalding]

It's the other set of points, the ones that close every 33 revs of the fan, that power the pump.

[ZacharyRitter]

Thank y'all so much! Just finished gapping the other set of points. It fired up within seconds. I bet that thing hasn't ran in 25 years.

[Ray Syverson]

Hopefully it is ok to jump in here at this point. I have been having the same issue where my fuel pump does work when I test it with an alternate 12 volts. It clicks as it should when I intermittently shoot the juice to it. But when I tried starting the heater all I got was the fan running, but no wonderful clicking sounds from the pump. The fuse was good, the reset button set good. It had run fine 2 years ago, but I haven't checked it periodically like I should have, and now it wont start. Yesterday I decided finally to pull the darn thing, take it apart, and clean the points. Now I've got it all apart and have the points exposed that are for the fuel pump circuit. Questions I have are:

1. What can I use to clean the points? Some kind of fine sandpaper?
2. It was a heck of a job getting the inner part of the heater separated from the shell. Is there an easier way to do this? Mine is a heater from a late 73 Thing and I had to spread the shell apart until I thought it would surely stay bent. Hate to think of putting things back together.
3. Is it possible to check the capacitor without removing it? What would I need to do?
4. Should I lubricate anything? I see there is a felt pad for the other points which I suppose gets a drop of oil?

Thanks for any advise any of you can give me. I haven't been on the Samba for a few years.

[ZacharyRitter]

1. You should always replace your points from what I am told. BUT I cleaned my points with an emory board (fingernail file) and re adjusted the points setting. Just to clarify becuase I didn't know this: there is 2 sets of points on the fan. I learned this after I took it apart and put it back together. One that controls the spark of the plug/glowplug and one that controls the fuel pump. The one for the fuel pump only makes connection 1 time every 33 revolutions of the fan. You can tell that you have the fuel pump one because it has a plastic gear that run off the fan shaft.
2. You should not have that much trouble pulling it apart of putting it together. You should be able to take off the 4 bottom screws and seperate it and remove the clamp that is holding the fan to the heat exchanger. If needed spread the housing a little bit and turn the entire assembly inside so the bolt for the clamp is accessiable. Install in the reverse order except you can move the clamp where it is easier to install using a ratchet with a long extension.
3. I checked my capicator while in place and used the ohms setting on my volt meter. I think it should have resistance of 400 (I think). Read the side of the casing of the capacitor.
4. I did not lubricate the felt pad as it had some form of a lubricant already on it. As for the other side I used a little bit of grease only on the gear itself.

This is what I done to get my heater back in running condition. Hope this helps you.

[Ray Syverson]

Thank you Zachary. Yes I have both sets of points exposed. I cleaned them today using very fine sandpaper(320) and will follow up with some 600 then check the gaps again. I need to get a new battery in my digital multimeter before I try testing the capacitors. Hopefully they will show what they should.
I wish I had thought about just removing that fan section from the heater shroud instead of struggling to remove the shroud completely first. I hope I'll be able to get it all back together ok. If anyone has any tips on this I'd like to hear them. Thanks