Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts  See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
BN-4 Heater Timer
Page: 1, 2, 3, 4  Next
Forum Index -> Thing/Type 181 Share: Facebook Twitter
Reply to topic
Print View
Quick sort: Show newest posts on top | Show oldest posts on top View previous topic :: View next topic  
Author Message
tnjanderson
Samba Member


Joined: August 27, 2006
Posts: 39
Location: Puyallup, WA
tnjanderson is offline 

PostPosted: Sat Jan 01, 2011 11:14 am    Post subject: BN-4 Heater Timer Reply with quote

Hi folks! I've read all of the BN-4 related postings, but do not see anything describing my situation. Basically, after running for 3 minutes or so, my 16 amp fues (the one in the fuse box) pops and everything shuts down. I've tested the motor points, cleaned the flame switch, etc., but no joy. I suspect the problem may be in the timer switch, but cannot find any postings discussing how to test the timer. I have the THING Shop manual, but it does not give much information on the timer itself. Can anyone help me with a timer test procedure? Many thanks in advance!
Back to top
View user's profile Send private message Classifieds Feedback
Captain Spalding
Samba Member


Joined: February 19, 2005
Posts: 2515
Location: . . . in denial.
Captain Spalding is offline 

PostPosted: Sat Jan 01, 2011 11:41 am    Post subject: Re: BN-4 Heater Timer Reply with quote

tnjanderson wrote:
Hi folks! I've read all of the BN-4 related postings, but do not see anything describing my situation. Basically, after running for 3 minutes or so, my 16 amp fues (the one in the fuse box) pops and everything shuts down. I've tested the motor points, cleaned the flame switch, etc., but no joy. I suspect the problem may be in the timer switch, but cannot find any postings discussing how to test the timer. I have the THING Shop manual, but it does not give much information on the timer itself. Can anyone help me with a timer test procedure? Many thanks in advance!

Another route to take would be to bypass the timer switch and see if the fuse still blows. Unplug the connector going into the back of the switch, and then jumper the red and grey wires to turn the heater on. If that is successful, i.e. the fuse doesn't pop in three minutes, then jumper the black and gray wires with the ignition switch on. If the fuse doesn't pop, you know the problem is in the switch.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
tnjanderson
Samba Member


Joined: August 27, 2006
Posts: 39
Location: Puyallup, WA
tnjanderson is offline 

PostPosted: Sat Jan 01, 2011 4:03 pm    Post subject: BN-4 Heater Timer Reply with quote

Captain Spalding:
Thanks for the reply. I first started the heater up and let it run. At about 2 minutes, the 16 AMP fuse blew. I turned the system off and put in a new fuse immediately. When I did so, the fan came on (even with key and switch off) as I would expect --- the cool down cycle. When it shut down, I crossed the red and gray wires. 16 Amp blew immediately. Then I crossed the black and gray, turned the key on and blew it again. I guess the problem is not in the switch at this point. Any other thoughts on what I might try in my efforts to run down the real problem?
Manya thanks in advance!
tnjanderson
Back to top
View user's profile Send private message Classifieds Feedback
Captain Spalding
Samba Member


Joined: February 19, 2005
Posts: 2515
Location: . . . in denial.
Captain Spalding is offline 

PostPosted: Sat Jan 01, 2011 4:39 pm    Post subject: Re: BN-4 Heater Timer Reply with quote

Hmm. Strange that there was a delay with the switch but none with simple crossing of wires. For no logical reason I'm tempted to suspect a short before a component failure. I guess step one would be to check out the gray wire and the solid blue wire - check the connectors at the ends and check for continuity to ground. Have a look at the relay and the other components on the heater and make sure none of the connectors are touching one another, particularly the safety switch (where the gray wire connects).
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Emeritusx
Samba Member


Joined: June 20, 2008
Posts: 2775
Location: 12 inches behind the wheel
Emeritusx is offline 

PostPosted: Sat Jan 01, 2011 5:44 pm    Post subject: Reply with quote

The heater is lighting right? And runs for awhile blowing hot air before the fuse pops?

When the thermo-switch flips could be when the fuse pops.

Image may have been reduced in size. Click image to view fullscreen.
Back to top
View user's profile Send private message Visit poster's website Facebook Gallery Classifieds Feedback
Captain Spalding
Samba Member


Joined: February 19, 2005
Posts: 2515
Location: . . . in denial.
Captain Spalding is offline 

PostPosted: Sat Jan 01, 2011 5:55 pm    Post subject: Reply with quote

FYI, other BN-4 circuit diagrams in the Samba technical section, here and here.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
[email protected] Premium Member
Samba Member


Joined: February 21, 2003
Posts: 832
Location: Clifton Park NY Saratoga County
mpb181@aol.com is offline 

PostPosted: Sun Jan 02, 2011 8:58 am    Post subject: Reply with quote

sounds like either your gas pump is not working or your spark plug is dirty
_________________
Michael Basso
http://www.thingparts.com
New and Used VW Thing Parts Free advice
CALL 518 630 0173
Back to top
View user's profile Send private message Send e-mail Visit poster's website Facebook Gallery Classifieds Feedback
tnjanderson
Samba Member


Joined: August 27, 2006
Posts: 39
Location: Puyallup, WA
tnjanderson is offline 

PostPosted: Sun Jan 02, 2011 12:11 pm    Post subject: BN-4 Heater Reply with quote

Thanks Emeritusx, Captain Spalding and Mike Brasso. I have cleaned and checked everything and concluded it must be in the thermo switch inside the Flame Sensor, or possibly the Safety
Switch --- or a combination of the two. I add in the Safety Switch because when I disconnect the fuel pump (by removing the 8 amp fuse), the fan motor will continue to run essentially forever. I thought it might be the cold air keeping it running, but when I put my torpedo heater next to the car and put a lot of hot air into the fan intake, the fan still runs on forever. I quit timing it at 10 minutes. So, problem still persists. Heater comes on just fine, but after 2 to 3 minutes, the 16 amp fuse blows. When I immediately put in a new fuse, the fan kicks in until the appropriate cool-down period is passed.
Any additional thoughts before I start buying parts on a trial-and-error approach????
Many thanks in advance
tnjanderson
Back to top
View user's profile Send private message Classifieds Feedback
Emeritusx
Samba Member


Joined: June 20, 2008
Posts: 2775
Location: 12 inches behind the wheel
Emeritusx is offline 

PostPosted: Sun Jan 02, 2011 2:06 pm    Post subject: Reply with quote

So it never lights? you never said if it was blowing heat..
Back to top
View user's profile Send private message Visit poster's website Facebook Gallery Classifieds Feedback
tnjanderson
Samba Member


Joined: August 27, 2006
Posts: 39
Location: Puyallup, WA
tnjanderson is offline 

PostPosted: Sun Jan 02, 2011 2:17 pm    Post subject: BN-4 Heater Reply with quote

Folks:
Sorry for the confusion. The heater does light up and provide heat as normal --- just quits after about 3 minutes when the 16 Amp fuse blows.
Any additional thoughts????
tnjanderson
Back to top
View user's profile Send private message Classifieds Feedback
Emeritusx
Samba Member


Joined: June 20, 2008
Posts: 2775
Location: 12 inches behind the wheel
Emeritusx is offline 

PostPosted: Sun Jan 02, 2011 5:05 pm    Post subject: Reply with quote

That pretty much rules out the cold circuit, and the fact that your heater fan never shuts off means it doesn't seem to be going back to cold ... I would start with the thermal-switch. Using the diagrams the captain left (print them) you can isolate circuits, it maybe something as simple as a wire is touching ground and when the flame good signal goes true that circuit grounds out.
Does this with ignition on and off right? that would rule out the dash switch.
Back to top
View user's profile Send private message Visit poster's website Facebook Gallery Classifieds Feedback
tnjanderson
Samba Member


Joined: August 27, 2006
Posts: 39
Location: Puyallup, WA
tnjanderson is offline 

PostPosted: Mon Jan 03, 2011 8:01 am    Post subject: BN-4 Heater Reply with quote

Emeritusx:
Thanks for the input. I'll be the first to admit I don't fully understand the diagram provided by the Captain, but I'll try to get someone to help me with that. Am I correct in assuming the thermal-switch is in the Flame Switch, and thus that might be the fist thing to replace?
Thanks again to all who are contributing to my problem resolution!!!
tnjanderson
Back to top
View user's profile Send private message Classifieds Feedback
Captain Spalding
Samba Member


Joined: February 19, 2005
Posts: 2515
Location: . . . in denial.
Captain Spalding is offline 

PostPosted: Mon Jan 03, 2011 11:54 am    Post subject: Re: BN-4 Heater Reply with quote

tnjanderson wrote:
Emeritusx:
Thanks for the input. I'll be the first to admit I don't fully understand the diagram provided by the Captain, but I'll try to get someone to help me with that. Am I correct in assuming the thermal-switch is in the Flame Switch, and thus that might be the fist thing to replace?
Thanks again to all who are contributing to my problem resolution!!!
tnjanderson


Just for fun, you might try manually cycling the reset switch on the back of the safety switch a few times and then fire up the heater again and see what happens.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
tnjanderson
Samba Member


Joined: August 27, 2006
Posts: 39
Location: Puyallup, WA
tnjanderson is offline 

PostPosted: Mon Jan 03, 2011 12:15 pm    Post subject: BN-4 Heater Reply with quote

Captain Spalding:
I tried that yesterday as I was attempting to get the Safety Switch to work properly. When the fan is runing, I can activate the switch and things shut down as expected. I also activated it several times (no power applied) during some of the other troubleshooting efforts. Given that it does not operate as the heater maintenance manual suggests (i.e., does not shut down after 120 - 180 seconds with the fuel pump disconnected), I'm pretty sure it is defective. I'm just not sure if it is a separate issue unrelated to the 16 amp fuse blowing, or a direct part of the fuse problem.
More testing once I get some additional fuses. thanks for your inputs!
tnjanderson
Back to top
View user's profile Send private message Classifieds Feedback
29thSS
Samba Member


Joined: August 25, 2010
Posts: 3
Location: Lookout Junction, California
29thSS is offline 

PostPosted: Mon Jan 03, 2011 1:05 pm    Post subject: Reply with quote

Ok, I have heard these things turn into flame throwers after time. Is this true and if it is why not switch to an electric heater?
Back to top
View user's profile Send private message Classifieds Feedback
Emeritusx
Samba Member


Joined: June 20, 2008
Posts: 2775
Location: 12 inches behind the wheel
Emeritusx is offline 

PostPosted: Mon Jan 03, 2011 5:12 pm    Post subject: Reply with quote

29thSS wrote:
Ok, I have heard these things turn into flame throwers after time. Is this true and if it is why not switch to an electric heater?


You heard wrong. These heaters have been around forever and their safety record is exemplary. At 12V you need 100 amps to get a measly 1200 watts.. An electric heater will never work in a stock VW.

Anyway.. The block diagram above is best to learn how it works, read top to bottom left to right...

Switch on, a nc (edit NC = Normally Closed) contact on the flame sense relay allows CR to energize as long as temp reg falls in the range it was set for (it opens and closes to regulate temp)

Now that CR is energized Contact M J (edit Normally Open) conduct and Fan Motor turns on, Also powering the spark coil. Also Powering the Glow Plug through thr Thermo-Switch And powering the Flame safety Relay

If Flame safety does not see a flame within X seconds it opens and shuts the whole thing down.

Now once the Thermo-Switch switches to HOT Flame Safety is powered down and the glow plug is switched out of the circuit (reducing power consumption by quite a bit)

Thermo Shitch at Hot and the spark coil maintains power all the time, now you can regulate fuel flow (using Normally open contact MB) by opening and closing CR. This allows unit to cool once powered down... Very ingenious engineering - beautiful in its simplicity.

This all applies to the ladder diagram posted above.
Back to top
View user's profile Send private message Visit poster's website Facebook Gallery Classifieds Feedback
29thSS
Samba Member


Joined: August 25, 2010
Posts: 3
Location: Lookout Junction, California
29thSS is offline 

PostPosted: Mon Jan 03, 2011 5:47 pm    Post subject: Reply with quote

Well hell thats cool. I guess I am going to get to work on min them as it is 17 degrees outside and I would like a heater. Thanks for the info man.
Back to top
View user's profile Send private message Classifieds Feedback
Captain Spalding
Samba Member


Joined: February 19, 2005
Posts: 2515
Location: . . . in denial.
Captain Spalding is offline 

PostPosted: Mon Jan 03, 2011 7:58 pm    Post subject: Reply with quote

29thSS wrote:
Ok, I have heard these things turn into flame throwers after time.

Yep. Everyone has heard that. Funny thing is that with all those stories floating around about a heater belonging to a friend of a friend that blew up, you never hear anyone say "my heater blew up."

Emeritusx wrote:
Anyway.. The block diagram above is best to learn how it works, read top to bottom left to right...

That's the most lucid and succinct description of how the heater works that I've ever seen. Bravo.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Emeritusx
Samba Member


Joined: June 20, 2008
Posts: 2775
Location: 12 inches behind the wheel
Emeritusx is offline 

PostPosted: Mon Jan 03, 2011 8:28 pm    Post subject: Reply with quote

thanx
Ladder (relay) logic is my forte... Above all else.. I tinker in vw land and am at best an apprentice mechanic, but that kinda stuff I really love to do and am good at. It is the language that runs almost all automation in the industry, but is slowly becoming old school...
Back to top
View user's profile Send private message Visit poster's website Facebook Gallery Classifieds Feedback
Captain Spalding
Samba Member


Joined: February 19, 2005
Posts: 2515
Location: . . . in denial.
Captain Spalding is offline 

PostPosted: Mon Jan 03, 2011 9:32 pm    Post subject: Reply with quote

Okay. Now that I've stared at the ladder diagram, I'm becoming a fan of the if/then/else nature of it. But, as I look at the ladder diagram and compare it to my wiring diagram, I don't think it jibes. I'm not saying one or the other is wrong - maybe I just don't get it. But could someone look at both and compare?

Edit: I think the logic is correct, but the labels might be switched in a few places. Check me on this. Third rung down, hot and C should be reversed, no? And J and B on the relay (CR)?


Last edited by Captain Spalding on Fri Jan 07, 2011 9:44 am; edited 1 time in total
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> Thing/Type 181 All times are Mountain Standard Time/Pacific Daylight Savings Time
Page: 1, 2, 3, 4  Next
Page 1 of 4

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

About | Help! | Advertise | Donate | Premium Membership | Privacy/Terms of Use | Contact Us | Site Map
Copyright © 1996-2020, Everett Barnes. All Rights Reserved.
Not affiliated with or sponsored by Volkswagen of America | Forum powered by phpBB