Turn signal intermittent Repaired

220629

Well-known member
The splice 226/227 issue was cross-checked on the relevant pages.

--dick
The theoretical wire was cross-checked using logic and deduction.

In 8w-10-18 they are consistent with the error for Fuse #1 Right Side Lights.

8w-10-18 Right Run Light.png

The Fuse #11 Left shows the connection in 8w-10-26.

8w-10-26 Left Run Light.png

This 8w-50-4 schematic is more complete. The direction of current is more obvious.

8w-50-4 Running Lights01.png

I don't find any alternative routes for right side lights power. Can someone explain how the Right Side Running lights get power when in the "Run" position without my "theoretical" connection?

******************

As an aside, without OEM DRL there are no headlamp or other running light relays. Similar to the Espar Heater "Except" notes, the "Except DRL" needs to be noticed. One problem with the DRL relays is that they don't label them DRL or Except DRL in many of the schematics. You are left to somehow figure out that they are DRL related. Eg. - 8w-10-26 and small sized 8w-50-4 above.

8w-10-27 Headlamps.png

SOME FURTHER CORRECTIONS.

TurnSigs04switch-APnotesCorrectedSm.png



:cheers: vic
 
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deandre

Member
Not a problem with Turn signals, but my intermittent windshield wipers sometimes don't work until I engage the left tun signal. Weird! What? Any thinking on this?
 

158wb

Member
Ok boys I could look at the electrical schematic for hours and not really understand it, will one of you comment. How does removing my wiper fuse cause the turn signals not to function. Please try it on your T1N, maybe mine is an anomoly. HOpefully not...
 

autostaretx

Erratic Member
Do you mean Fuse #6 on the steering column panel? ("wiper motor" on my 2005 list)

OK.... looking at the 2006 wiring diagram (page 8w-53-2), that fuse powers the
"Wiper/Turn Signal/Engine Start Control Module".
I think that explains it.

WiperFuse.png

--dick (and i'll annotate my own fuse list... thanks for the heads-up :thumbup:)
p.s. but removing the fuse doesn't interfere with starting the Sprinter??? :thinking:
((egad ... following the drawing index's citations of that module is very confusing)) :wtf:
 
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220629

Well-known member
The Fuse #6 tentacle is another example of how incomplete the fuse maps/lists can be.

...
((egad ... following the drawing index's citations of that module is very confusing)) :wtf:
I'm less than impressed with MB's documentation.

The Euro convention of schematics differs from the USA type, but once one gets a bit familiar with it the convention works. The Brown Boveri Turbine Generators we serviced had rather complex control schemes, but the electrical schematics were excellent.

One of MB's little idiosyncrasies is to include an arrow off a line with no reference to another drawing. The information supposedly provided by the unmarked arrow(s) is not always minor.

As an example related to turn signals.
https://sprinter-source.com/forum/showthread.php?p=739711#post739711

8w-52-2 EmergFlasherPartial (1).jpg

8w-50-5 TurnSignalPartial (1).jpg

The arrows do show that there is connectivity to some other place, but they don't point to where.

Beware the arrows. They go to another drawing, MB just doesn't bother to tell you which one.

Note that there are seven different arrows in 8w-52-2 with no notes.

:cheers: vic
 

158wb

Member
So does fuse 6 then power the other fuse next to it (not sure of number), for the turn signals, because they have their own fuse as well. That would make sense I guess, just not sure why it is double fused...
 

158wb

Member
Also I see engine start control module included, however my van appeared to start correctly without fuse 6 inserted.
 

autostaretx

Erratic Member
Also I see engine start control module included, however my van appeared to start correctly without fuse 6 inserted.
Yes, trying to track down how/what/where/why the "start module" did is what spawned my "egad!" comment. I still haven't figured it out (ok, ok... nor wasted more time on it:whistle:).

I'll look into "does fuse 6 subsequently power fuse XX?" ... that's in the "power distribution" section of 8W. ... i'm going to guess that it doesn't ... they normally don't cascade small fuses.
(?? by "next to it", do you mean in the diagram, or in the fuse box??)
The diagram's Fuse 9 (on the left) is from "always powered", whereas Fuse 6 is powered from the ignition switch. Those are not cascaded.

--dick
 
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autostaretx

Erratic Member
I think i figured out the "meaning" of those "sideways arrows to nowhere" ...

They mean that that Fuse in Block 1 (FB1) connects via internal copper bars (or wires) to other components that are also a part of FB1.

Here's page 8w-10-21 ... where the "bottom" of fuse 6 connects to the wiper system and also (via pin2 on C3) off-board:

8w-10-21-Fuse-6.png

Fuse 9 is totally separate from Fuse 6 ... the feed into Fuse 6 comes from the ignition switch.

--dick
 
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220629

Well-known member
I think i figured out the "meaning" of those "sideways arrows to nowhere" ...

They mean that that Fuse in Block 1 (FB1) connects via internal copper bars (or wires) to other components that are also a part of FB1.
...
--dick
I came to basically the same conclusion, but that doesn't help the fact that they aren't at all labelled, and that where the arrows go does matter when attempting to follow/troubleshoot using the schematics.

Another revelation for those who haven't figured it out.

The "Wiper/Turn Signal/Engine Start Control Module" label isn't a specific reference.

Wiper/Turn Signal/Engine Start Control Module = Fuse Box #1 aka FB#1.
The FB#1 module includes all of those functions listed.

The power from Fuse #6 is just one of the power feeds within the module. The power inputs don't all necessarily relate to starting or ALL functions. Some are specific to one of the sections/circuits.

Then again. I'm also still learning so FWIW.

:cheers: vic
 

158wb

Member
OK, I think i understand what was happening. My hazard/flashers/e-lights switch would turn on the turnsignals, when I had fuse 6 pulled, because the blinkers are are powered through 9, and able to be activate by the hazard light switch independently. Normally however, they are activated by the multi fuction switch when the ignition is keyed on, through fuse 6 (even though this is called wipers, only). I think.

My confusion arose when my turn signals operated with the hazard lights switch activated but not the turn signal when fuse 6 was removed. If Im not mistaken above, this makes sense now.
 

UKmtrsp

Active member
Hey guys having the same or similar issue. Intermittent signals and sometimes no 4-way. Sometime the signal lights flash just once. Others plain doesn't work from the get go. Also get a sound like dragging my finger on a comb. Last observation is that the problem seems to arise with an increase in significant humidity. I thought it must be the MFS initially, then reading this thread made me back away from pulling the trigger. I do have a trailer wiring setup. So what should I be eliminating in order to diagnose this properly? Thanks
 

Cheyenne

UK 2004 T1N 313CDi
Hey guys having the same or similar issue. Intermittent signals and sometimes no 4-way. Sometime the signal lights flash just once. Others plain doesn't work from the get go. Also get a sound like dragging my finger on a comb. Last observation is that the problem seems to arise with an increase in significant humidity. I thought it must be the MFS initially, then reading this thread made me back away from pulling the trigger. I do have a trailer wiring setup. So what should I be eliminating in order to diagnose this properly? Thanks
Start by replacing the turn signal relay in the bottom of fuse box #1 and see if that helps.

Keith.
 

autostaretx

Erratic Member
Some trailer wiring setups put a relay box at the bottom of the D (rearmost) pillar ... where they can get wet.
Wet relays corrode and do other odd things

--dick
 

UKmtrsp

Active member
definitely humidity related...rained last night...no signals this morning on drive out to my sons tennis tournament...after his match and van sitting in the sun for an hour they worked on the drive home.
 

UKmtrsp

Active member
Update: Found that when the signals stopped working, pushing on the under column fuse cover helped to get them working again. Of course its pouring right now and probably the rest of the weekend so full diagnosis and repair will have to wait a bit.
 

UKmtrsp

Active member
Ordered a flasher relay today from Europarts SD. I also pulled and reinstalled the old one just to see if the connections looked odd. They did not, but I may keep the new relay as a spare and see if just the pull and re-install did the trick. (Waiting for the next rain Chip)
 

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