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Discussion Starter #1
Can anyone out there confirm the wiring for the 4 terminal black flasher box.
Bosch Part #0336 401 004

Terminal 31 (i have Blue/ Black wire going to indicator dash bulb)
Terminal KBL ( i have White wire. Unsure where this goes. Not on in my diagram)
Terminal 49 ( i have red wire from fuse #3)
Terminal 49A ( i have Black and Black/White negative feeds from hazard switch and indicator stalk switch)

Is this wired properly? I have no 4-ways and no indicators. When energized this box just chatters. Fuse is good. All bulbs are good. All wiring appears good. Wondering if the box is wired wrong. I have 2 boxes and both do the same thing.
Help!!

79 Spider
 

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49 & 49a are wired correct.

KBL should be blue/black (to dash indicator)
31 should be a black wire to ground
 

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Discussion Starter #3
Thanks.
No difference. Still chattering away.
Could both my flashers be bad? Is there a test for them?
Bad grounds at the bulbs? Rear grounds I tested. haven't tested the front grounds yet
All the bulbs tested good.
Fuse tested good
 

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Discussion Starter #4
Ok
So I hotwired the circuit. I disconnected the 49A wires and jumped them right to the fuse panel.
All the lights come on properly when the 4way switch is selected (without flashing of course) and the left and right indicators work properly when selected (again without flash).

Kinda tells me everything is wired proper and leads me to a bad flasher/ Yes?
 

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Yep, sounds like the flashers are kaput.

What's interesting is that the wiring diagrams show that Alfa last used the 4-wire KBL flasher back in 1973. 3-wire flashers have been used since then.
Simple fix is to pick a #550 flasher from your local autoparts store and wire it thus;
terminal X - red wire from fusebox
terminal L (Load) - black and black/white wires
terminal P (Pilot light aka dash indicator) - blue/black
There is NO ground.

If the dash indicator does not work, let me know.
 

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back from the dead. I found this post in trying to fix the wiring BS on my '72 GTV (link to that nightmare below) so I tried this 3 wire flasher upgrade using the wiring listed above in post 5 & it did not work. Is there something I am missing? The 2 wires coming to the terminal 31 on the stock flasher unit were the only things that didn't get transfered to the new flasher, but from what I can tell they are just grounds - right?

my wiring nightmare:(
http://www.alfabb.com/bb/forums/spider-1966-up/181288-4-wire-black-flasher-wiring.html
 

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Bringing this back from the dead. My turn signals and hazards all work correctly. I am simply trying to get the signal light on the dashboard of my 71 GTV to flash. I have tried a new flasher unit and nothing. When I turn on the hazards or the turn signals the dash indicator light will blink once and then remain off no matter how long I leave the flashers on. Any ideas on what the issue might be?

I did notice that if I take the blue/black wire that normally goes on the KBL terminal and I touch it to the 49a terminal things all work as they should including the dash flasher light. Would there be harm in soldering the blue/black wire the connector on that terminal so that it works?
 

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When I turn on the hazards or the turn signals the dash indicator light will blink once and then remain off no matter how long I leave the flashers on. Any ideas on what the issue might be?
That is a common symptom with mechanical flashers. You can pry off the "can" and polish the terminals with emery cloth to fix the problem, but it will re-occur. Another fix is to replace the $5 mechanical flasher with a $12 electronic flasher (not big bucks either way!). I installed a Carquest #7123 in my '70 BMW to solve this problem.
 

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Thanks for the response, that makes sense. Electrical has never exactly been my strong suit.

The thing that still strikes me as odd though is that it still didn't work with the brand new mechanical flasher that I tried out so would the theory of needing to polish the terminals still hold true?

As far as your electronic flasher suggestion I don't see a Carquest part 7123 on their site, but most flashers I see out there are three terminals with a Ground, Power, and Load. With this set-up I would likely have to wire the dash indicator light (blue/black wire) to the Load terminal anyway right, so maybe I just do that with my existing relay until it decides to go out.
 

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The thing that still strikes me as odd though is that it still didn't work with the brand new mechanical flasher that I tried out so would the theory of needing to polish the terminals still hold true?
I didn't realize you had a new flasher unit. No, I wouldn't advocate taking that apart and polishing its terminals.

Your indicator may begin to work normally if you polish up the connections to the bulbs, ensure the bulb grounds are good, ensure the bulbs are the correct wattage, etc. Even new bulbs will sometimes make a difference. And no, I can't explain why increasing the current to the exterior bulbs would make the indicator work - but it does. This is a common problem on BMW's of comparable vintage; see the thread at: http://www.bmw2002faq.com/topic/131769-turn-signal-problem/

As far as your electronic flasher suggestion I don't see a Carquest part 7123 on their site, but most flashers I see out there are three terminals with a Ground, Power, and Load. With this set-up I would likely have to wire the dash indicator light (blue/black wire) to the Load terminal anyway right, so maybe I just do that with my existing relay until it decides to go out.
I'm sorry, "7123" was a typo. The Carquest # should have been FSH7312. Note that many companies supply these flashers; the one my local car parts store happened to carry was the Carquest FSH7312. My reference for this is at: http://www.cecindustries.com/attachments/Flasher_PartNo_Interchange.pdf See the second line on the second page.

I did notice that if I take the blue/black wire that normally goes on the KBL terminal and I touch it to the 49a terminal things all work as they should including the dash flasher light. Would there be harm in soldering the blue/black wire the connector on that terminal so that it works?
In thinking about it, there IS a problem with wiring your indicator light to the same terminal (49a) that goes to the switch on the column and the 4-way switch: that terminal is always hot, but current can only flow when you move the lever on the column to the "L" or "R" position to complete the circuit. If you connect the indicator there, the flasher will always send some current through the indicator, since there is no switch in that circuit. The indicator is a small wattage bulb, so the amount of current may be too low to make the flasher cycle, but the light will glow a little. I believe your flasher is always powered (not just when the ignition is on), so that may be enough of a drain to kill your battery after a few days.
 

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So the saga continues. When using a #550 flasher, as Papajam mentions above, the dash indicator light does not blink. The wiring at the indicator light bulb has one wire (black/blue) going to the P terminal on the flasher and the other wire (red) goes to the fuse box. If I remove the red wire from the bulb and ground that terminal so that the bulb now has a ground wire and a wire leading to the P terminal on the flasher everything works perfectly. From what I can tell using the multimeter this does not cause any excessive draw at any points which might lead to a dead battery. Again, electrical is not my thing but maybe the #550 flasher just functions differently than the stock flasher? This thing is a pain in the neck, literally...
 

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...maybe the #550 flasher just functions differently than the stock flasher?
Yep.
The KBL terminal on the stock flasher provides a pulsing ground for the dash indicator while the 'P' (Pilot) terminal on the #550 pulses power. As such, the always hot (red) wire on the indicator needs to become the indicator light ground (just like you did :thumbup:).
 

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Its very likley your grounds. When my spider came out of its P/O induced vacation my turn signals would blink once, and that was it. It was a ground issue with the front lights. Also, then the headlights were on, they wouldn't work at all.... Also a ground issue.
 

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Yep.
The KBL terminal on the stock flasher provides a pulsing ground for the dash indicator while the 'P' (Pilot) terminal on the #550 pulses power. As such, the always hot (red) wire on the indicator needs to become the indicator light ground (just like you did :thumbup:).
Great! Thanks for confirming. Seems like my stock flasher must have just stopped pulsing at the KBL terminal which was the original problem probably driven by a need to polish the terminals as Alfajay suggested. I will just keep the #550 flasher in the car and nix the hot (red) wire and replace with a ground. Thanks for the help everyone.
 

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Seems like my stock flasher must have just stopped pulsing at the KBL terminal which was the original problem probably driven by a need to polish the terminals as Alfajay suggested. I will just keep the #550 flasher in the car and nix the hot (red) wire and replace with a ground.
OK, maybe I didn't understand the full story. I think you're saying you replaced your original flasher with a different model; that the original one required one leg of the indicator bulb wired to +12, while the replacement requires it to be wired to ground. Yea, that would make a difference! Retaining the new flasher and connecting that red wire to ground may be the simplest fix.
 
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