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Alaninin
Samba Member
Joined: December 04, 2023
Posts: 19
Location: Indiana
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 Posted: Mon Dec 04, 2023 5:00 pm Post subject: Wires under drivers seat |
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Just picked up a 411 yesterday. Now I need to fix all the issues. First I found these wires under the drivers seat not connected to anything. could anyone help here?
Next I have the horn is not working and found there is not a horn on drivers side. Need to locate one but don't think that is the problem.
FLASHER AND TURN SIGNALS BURN FUSES. FINDING LOTS OF ELECTRICAL ISSUES.
I hope there is help out there. |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
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| Posted: Mon Dec 04, 2023 9:07 pm Post subject: Re: Wires under drivers seat |
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| Alaninin wrote: |
Just picked up a 411 yesterday. Now I need to fix all the issues. First I found these wires under the drivers seat not connected to anything. could anyone help here?
Next I have the horn is not working and found there is not a horn on drivers side. Need to locate one but don't think that is the problem.
FLASHER AND TURN SIGNALS BURN FUSES. FINDING LOTS OF ELECTRICAL ISSUES.
I hope there is help out there. |
Your pictures are a little too close to see full context....but the yellow with red marks wire went to a hydrometer that was installed in factory batteries. It leads to teh diagnostic plug in the engine bay. When the dealer plugged the car in for testing it would tell them the battery state under load. Very cool...but you could never buy any other battery than factory that had that function.
The vast majority of wires under the seat connect to the battery. Brown wires are negative. But, there were also wires under the seat with a two prong plug that went to the seat buzzer switch built into the seta.
Let me look in my wiring diagram and I will post in the am. Ray |
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Alaninin
Samba Member
Joined: December 04, 2023
Posts: 19
Location: Indiana
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| Posted: Wed Dec 06, 2023 7:34 am Post subject: Re: Wires under drivers seat |
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| Thank you Ray!!! Do you think the brown wires both go to the neg battery terminal? |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
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| Posted: Wed Dec 06, 2023 11:29 am Post subject: Re: Wires under drivers seat |
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| Alaninin wrote: |
| Thank you Ray!!! Do you think the brown wires both go to the neg battery terminal? |
I am assuming that you have a 1972. So looking at the 1972 wiring diagram, as noted the yellow and red originally went to the sensor on the factory battery. The other end of that one goes to the diagnostic socket in the engine bay.
The solid brown wire goes to a tab/flag terminal on the ground braid where it connects to the batter. It ends up at the same diagnostic plug in the engine compartment.
The brown and white wire also connects to the ground braid but at the floor pan. It ends at the diagnostic plug in the engine bay as well.
The gist of what those two ground wires do is that when they plugged the car end they can measure the resistance end to end on the ground and tell if there is corrosion or poor connection and/or it is part of the diagnostic system of direct voltage measurement.
However because you pictures are too close and dark I cannot see EXACTLY where the wires go to. There are a couple more wires under the seat that are part of the seat sensor.
Let me look at mine and see what other possibilities there are. Ray |
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Alaninin
Samba Member
Joined: December 04, 2023
Posts: 19
Location: Indiana
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| Posted: Wed Dec 06, 2023 6:02 pm Post subject: Re: Wires under drivers seat |
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Thank you again!! It sounds like they should not be an issue but I will label them.
Next what do you think about what I found under the back seat? Is this correct? Do I need to change things? It looks like someone added two 30amp fuses. Should they be there? |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
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| Posted: Thu Dec 07, 2023 12:19 pm Post subject: Re: Wires under drivers seat |
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| Alaninin wrote: |
Thank you again!! It sounds like they should not be an issue but I will label them.
Next what do you think about what I found under the back seat? Is this correct? Do I need to change things? It looks like someone added two 30amp fuses. Should they be there? |
Ok...now is the time that you MUST get a book for this car. Yes, the basic wiring diagrams are here in the Samba. But you need some better diagrams and background for the gasoline heater.
But, you have a wagon model. So that means that you have probably three relays under the back seat.
The one on the left is the gasoline heater double relay. Very complex relay. The black one in the middle with the red switch on the side is the overheat safety switch for the gasoline heater. The small relay on the right is for the rear window defroster.
NO...the two 30 amp fuses SHOULD NOT be there. This is not saying that they cannot work....I KNOW why they are there. But what should be done is to fix the problem correctly orits possible...if certain items have been wired around....that the gasoline furnace, if its working at all....can lock into "operation mode" and not turn off.
That will in about 10 minutes...burn off the plastic outlet ducts and can light car on fire. Been there...very nearly done that! 
So, that olive green wire goes to the high limit cut-off safety switch in the top of the gasoline furnace. Its a simple bi-metallic capsule with a + wire on one side and a - wire on the other. When the furnace reaches a specific temperature....like when it gets too much fuel or if someone wires around the thermostat that cycles it.....the element inside warps with heat and connects the + to the -....a dead short....and blows an inline fuse....its supposed to be an 8 amp fuse.
This overheat fuse problem is a very common issue with these furnaces in type 4/ BA4 heater systems.
One of several things is normally happening.
1. This little disc shaped overheat switch fits into a little rubber bung in the top of the heater unit. With age, the rubber gets torn and switch body gets crooked and the + side dings up against the steel housing and POP....blows the fuse.
2. With people fiddling around, one or both of the crimped wires on that little bi-metallic switch get loose and people re-crimp them. It bends the disc and it causes it to blow at too low of a temperature.
Normally, this overheat switch blows at 300* F
3. This last one is a little uncertain....but there are times when this switch malfunctions and repeatedly blows the fuse...when the heater temperatures are normal and all seems to be functioning normally.
There was a very good and long discussion about this phenomena and other things in Pepperbilly's thread about his 412 restoration.
Looking back on this I believe that over time, like a lot of other bi-metallic switches....the bi-metal element fatigues. Also, this little disc shaped overheating switch as noted has two wires one is the olive green + wire going straight to supply at the double relay...and the other is the brown ground wire that shares the ground point with the main heater blower motor.
I believe that between the changes with age and possibly high resistance to ground, or maybe even high resistance to + at the relay or even low voltage....these wire resistance issues may be causing that little high limit switch to heat up like a resistance element.
Anyway......the usual answer or fix....done by otherwise circumspect owners.....is to swap the 8 amp white inline fuse....with a 25 amp blue fuse.
NOTE: the book I have says its a white 8 amp fuse. I have never in my life found a 411 or 412 with an operating heater that did not have a red 16 amp fuse in it. Never.
Also, on my first 411....once I figured out what was happening...it came with a 16 amp fuse and I replaced it with a 25 amp fuse....and it fixed the issue. Nothing got hot, never had any issues and I ran with it that way for years.
Cut to 6 years later with a different 412...different heating system....and it had an excellent operating furnace....and it would not operate without a 25 amp fuse either.
I personally think these should have had a 16 amp fuse when new. Its also worth it to remember....that all this emergency overheat circuit is feeding is the heater fuel pump. Thats how it shuts down. The circuit blows and the pump stops so no fire.
I should have also mentioned that the extra resistance could also be coming from the solenoid driven fuel pump or its ground.
Here is a list serve that has a lot of type 4 Gasoline furnace info in it along with many other things. Its not just type 4 stuff.
http://oacdp.org/ebersp.html
Here is a link to the Eberspacher BN4 heater system book in my dropbox
https://www.dropbox.com/sh/p553vqw4unfwrtk/AAALpHMrqDMHKOX23X58JVuha?dl=0
This has most of the information you need. Our cars use the BA4. The bus uses the BN4....they are primarily the same component wise.
What I would do is look tat he wiring diagram and hook everything back up normally.
Then see what happens, what operates and what blows....and then we can work from there.
And, those yellow, red and blue hardware store crimp connectors need to be gotten out of there. They have no place in cars and will cause issues. Ray |
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