Author Topic: Turn signals and Hazard switch problems  (Read 971 times)

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Offline BDA

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Turn signals and Hazard switch problems
« on: Monday,September 16, 2019, 01:08:42 PM »
Until recently, all this stuff has worked fine but now, with no electrical changes, I have the following problem I'm having trouble figuring out (all tests with ignition on):

1. Neither of my turn signals work at all but the horn and bright headlights (controlled by the turn signal stalk) work.

2. If I switch on the hazard switch by itself nothing happens.

3. If, while the hazard switch is switched on, and either of the turn signals are selected, all my hazard lights flash.

4. The Purple wire going into the turn signal switch is hot.

5. With the hazard switch turned off and one of the turn signals turned selected, the proper Green/White or the Green/Red wire at the steering column switch is hot as expected.

6. With the hazard switch turned off and no turn signal selected, there is no voltage at the Purple/Blue wire at the indicator flasher (as I expect from the wiring diagram).

7. With hazard switch turned on and no turn signal selected, there is no voltage at the Purple/Green wire of the hazard flasher.

8. With the hazard switch turned on and a turn signal selected, there is voltage at the Purple/Green wire at the hazard flasher but not at the Purple/Blue wire at the indicator flasher. Obviously, all my fuses in the original fuse box are intact.

9. With the hazard switch turned on or off, you can hear the relay in the DB10 under the dash when selecting a turn signal.

I have LEDs for all my signal, brake, and reverse lights. I have two LED compatible flashers (one for the emergency flashers and one for turn signals). I have swapped the flashers and there is no change.

My car is 3635R so it should conform to the pre 73083924 wiring diagram (http://www.lotus-europa.com/manuals/misc/electrical/tcsearly.gif). I've also attached a clip of the pertinent section of the wiring diagram. 

From the diagram, it looks like when the hazard switch is turned off (the default situation that is, I believe, shown in the diagram - i.e. a Purple wire going into the Hazard switch on one pole of the switch seems to connect that wire Purple wire to the Purple/Blue wire going into indicator flasher) the the Purple/Blue wire to the indicator flasher should be hot (but that would mean that the flasher is always flashing!).

I'm beginning to think there is something wrong with my hazard switch, which doesn't excite me since it means unbolting the dash!

Can somebody help me understand how the hazard switch is supposed to work (beyond flashing all the turn signals, of course!)? Or provide some insight into what is or isn't happening and why?

edit: cleared up some punctuation and hopefully made my descriptions a bit more easily understood.
« Last Edit: Monday,September 16, 2019, 06:18:37 PM by BDA »

Offline dakazman

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Re: Turn signals and Hazard switch problems
« Reply #1 on: Monday,September 16, 2019, 05:42:52 PM »
 BDA, here is some info , first.

http://www.lotus-europa.com/manuals/misc/electrical/The%20Lucas%20DB10%20Relay.doc
europa.com/manuals/misc/electrical/DB10.jpg

http://www.lotus-europa.com/manuals/misc/electrical/The%20Lucas%20DB10%20Relay.doc
 
Try removing the green wire fuse . Since you mentioned the wire is hot. See what you have or don’t have.
Dakazman



Offline BDA

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Re: Turn signals and Hazard switch problems
« Reply #2 on: Monday,September 16, 2019, 06:31:14 PM »
Thanks for that write up about the replacement for the good ole DB-10.

You lost me about "removing the green wire fuse..." Can you clarify that. Also please check your links. Two of them seem like dupes and I think I think the europa.com one might be lotus-europa.com... Nice picture of how the DB10 fits into the wiring scheme.

Offline dakazman

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Re: Turn signals and Hazard switch problems
« Reply #3 on: Monday,September 16, 2019, 07:28:59 PM »
  Oops
http://www.lotus-europa.com/manuals/misc/electrical/DB10.jpg

the green fuse wire to brakes may be hanging up inside the relay pin 5. And check the condition of the ignition switch white wire. 
Dakazman

Offline jbcollier

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Re: Turn signals and Hazard switch problems
« Reply #4 on: Monday,September 16, 2019, 07:35:07 PM »
First question:  Do your brake lights work?

Second question: What are you using to check for voltage?

Offline jbcollier

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Re: Turn signals and Hazard switch problems
« Reply #5 on: Monday,September 16, 2019, 07:38:41 PM »
If your brake lights work, then we know the wiring from the DB-10 to the rear is good.

Digital voltmeters and LED test lights can "sniff" voltage down the darnedest of foul, black holes.  Use a test light with an incandescent bulb as it applies a load to the circuit and lets you know if there really is power there.

Offline BDA

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Re: Turn signals and Hazard switch problems
« Reply #6 on: Monday,September 16, 2019, 07:45:29 PM »
I thought that's what you meant.  :)
I'll check the ignition switch white wire but I have separate wire from the brake switch to the brake lights (I have the European red/white/amber tail lights) so the DB10 isn't used for brakes.

Offline BDA

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Re: Turn signals and Hazard switch problems
« Reply #7 on: Monday,September 16, 2019, 07:54:51 PM »
JB, my brake lights work but see my previous post about brake lights, I have a separate circuit for brake lights. I started using a volt-ohm meter but I'm just using a test light to see where I have current.

Offline shootingsight

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Re: Turn signals and Hazard switch problems
« Reply #8 on: Monday,September 16, 2019, 08:35:35 PM »
I did not invest a lot of time thinking about all your symptoms, but I can offer this:

If a ground connection from some device is compromised, you can get reverse electrical flow through adjoining devices.  Tail lights, brake lights, and flashers share ground connections.  So if the brake ground is open, the current flows through the brake light, then backwards through the other filaments, and backwards up through the turn indicators (which also have a shared ground), which illuminate when they find some other grounded wire ... So you can get very strange cross-acting connections.  Especially on a fiberglass car.  Check that your ground connections are good.
« Last Edit: Monday,September 16, 2019, 08:37:25 PM by shootingsight »

Offline BDA

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Re: Turn signals and Hazard switch problems
« Reply #9 on: Monday,September 16, 2019, 08:51:05 PM »
Interesting idea! I'll look at them tomorrow!

Offline Roger

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Re: Turn signals and Hazard switch problems
« Reply #10 on: Tuesday,September 17, 2019, 10:33:24 AM »
Been there, done that, wrote the article about the substitute.
First let's dispel a misunderstanding. The purple/ blue wire going into the indicator flasher should be live (don't like the word hot when talking Lucas, it has suggestions of smoke escaping) when the hazard switch is off, just as you say, but that doesn't mean there's any flashing because a circuit isn't complete until the indicator switch selects, via the DB10, one side or the other to flash.
The hazard switch bypasses the indicator flasher,  switches the hazard flasher, and via the DB10 again selects both sides to flash via the GR wire seen at the right-hand end.
I also see you have ignored the warning about operating the hazard switch and turn s signal simultaneously. See my document for explanation.

Anyway, to diagnose your problem. Since you have no power to the indicator flasher when the hazard switch is Off,  then if you have power to the purple wire going into the hazard switch, there's a problem, as you say, inside the hazard switch. So first, check that the purple wire is live at the hazard switch. You may hope it isn't, since that might be easiest to fix!
« Last Edit: Tuesday,September 17, 2019, 10:39:54 AM by Roger »

Offline BDA

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Re: Turn signals and Hazard switch problems
« Reply #11 on: Tuesday,September 17, 2019, 11:04:43 AM »
Thanks, Roger! I figured out (or pretty much figured out) the hazard part of the system but now you've explained the default (hazard switch turned off) part and your explanation is very helpful.

I did not ignore the warning to turn on flashers and turn signals at the same time, I was ignorant of it till, I think it was, last night. Hopefully I haven't broken anything! I looked for your document but I wasn't able to find it. Maybe you could repost it.

Offline Roger

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Re: Turn signals and Hazard switch problems
« Reply #12 on: Wednesday,September 18, 2019, 01:28:37 AM »
BDA, my document is the one linked by dakazman. The last paragraph.

Offline BDA

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Re: Turn signals and Hazard switch problems
« Reply #13 on: Wednesday,September 18, 2019, 06:26:14 AM »
Thanks, Roger!

Offline BDA

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Re: Turn signals and Hazard switch problems
« Reply #14 on: Thursday,September 19, 2019, 06:02:24 PM »
I had to take the dashboard off and found that somehow the purple wire off my hazard switch! I have no idea how that could happen but that's what seems to have happened. Now all I have to do is put all back together and make sure any wires that were dislodged because I had to snake my hands between them and make sure I attached all the grounds and on and on...