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Re: Dashboard / Instrument Light Woes

PostPosted: Sun Feb 17, 2019 3:11 am
by The Veg
stugilmour wrote:It is difficult to remove with dash in place. Veg has done it more recently so he is best to ask. From memory, knob is removed with a little catch pin in the knob. Bezzle piece unscrews from around shaft and then pull switch out. It is a very large vacuum switch, with (probably) two microswitches attached to the outside. They are really fussy to get aligned right.


Correct. There is another thread here somewhere about the spring-clip which holds the knob onto the shaft. Basically find the hole on the bottom of the knob and push the button in the hole with something, if I understand correctly. The clip on mine was replaced with a screw by a PO so I really can't advise from experience.

The bezel-nut is one of those types with a slot on either side. You may be tempted to try to remove it with needle-nose pliers but I don't recommend this if you don't want to damage your dashboard surface. You can make the tool with a bit of scrap pipe or tube and a rotary tool.

Also the elbows that connect the vacuum hoses tend to split easily but they are readily available from the usual suspects.

There is a thread on here with excellent photo?s of the light switch. I will try to find a link. This link shows a picture in a parts drawing. The microswitches are item 39 and there are two of them. Looks like it is post 50/1363.

http://www.lotuselan.net/wiki/BN_-_Body ... acuum_%2B2

What is your VIN? I am 50/2181. Note there were several running changes to the microswitch and vacuum switch setup in the Plus 2, but Veg and I have the version shown around item 39.


My switches seemed OK until one of them crumbled without warning in my hand, so be aware that age isn't always kind to them. Replacements were reasonably priced from an audio components supplier, as these are generic switches used in many non-automotive applications.

That said, have you checked the relay on the right heater box wall? Think that is where your issue is.


Agreed. If the relay isn't healthy and correctly wired, the sidelights won't function correctly. If yours is like mine, the wires will come off it if the dashboard moves even just a little.

Re: Dashboard / Instrument Light Woes

PostPosted: Sun Feb 17, 2019 7:36 pm
by chickenstock10k
Alright, just to follow up on a couple of the ancillary threads here...

VIN: I am 1781 and so, I think, I am just ahead of the the cutoff for the +2 / +2s cut off. My guess is that I'll keep finding quirky little crossover items.

Rear Heater: I don't know if this actually works since I don't see anything on the rear window that makes me think there is a heater. See above I guess!

OK, on to the instrument lights and troubleshooting. Stu, that chart was really helpful. After probing for hot and ground leads it became clear that the whole thing was wired totally backwards. After starting from scratch and wiring it correctly the relay seems to work just fine now. I can turn on the side lights and they stay on. The instruments and tail lights come on as well. So, it seems like the relay is working.

However, while it is safe-er to drive at night now, the instruments and tail lights don't come on when the headlight switch is pulled. What next?

I've included some before (incorrect) and after (correct) wiring photos for others that might stumble onto this thread.

Before (Incorrect)
before-small.jpeg and


After (Correct)
after-small.jpeg and

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 12:24 am
by stugilmour
Cool!

So as is often the case, more than one thing wrong, and little to do with the original issue. :D

The side lights are brought on when the headlight vacuum switch is pulled to the on (out) position. Note the sidelights will stay on when the vacuum switch is returned to the off (in) position. The sidelight rocker has to be pressed to the momentary off position to turn off the sidelights.

The likely issue is your sidelight microswitch is misaligned, misswired, or needs replacement. If you opt to get a replacement, recommend getting two and replace both the sidelight switch and the headlight switch as they are such a pain to get to and they are at this point a known failure point.

Changing them our requires removing the vacuum switch. IIRC you can do this by loosening all of the dash mounting screws and pulling the dash outward. IIRC the bottom two screws are not captive nuts so you have to reach in with an open end wrench. The sidecscrews also have a Ground for the courtesy/interior lights. You will have to remove the plastic housing from the steering column. Probably easier with the radio out, but mine is a different setup so check with The Veg for that detail. If you are patient and lucky, you will not have to remove the heater control cables, which is pretty difficult.

The biggest issue with disturbing the dash the first time is inadvertently disconnecting various wires by mistake and not being sure where they go. Proceed slowly and methodically, leave lots if time.

The microswitches have a Normally Open (NO), Normally Closed (NC), and Common terminal. The sidelight switch uses the NO and Common as per the PowerPoint diagram.

The microswitches are actuated by the pull handle and can just be misaligned.

You may wish to examine anything else that may need repair while the dash is out.

I also advise adding multi-connectors to allow full dash removal without having to fuss with the multitude of bullet connectors, but this is a mid rather than repair.

I will post a link to the microswitch part numbers shortly. As mentioned, they are readily available but you want the one that is the exact dimensions as stock for the pull to work.

Stu

PS I have been watching the last five minutes of Daytona for an hour and a half. Worse than the Super Bowl clock management! :D

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 12:42 am
by stugilmour
Here is a link to the thread with excellent pictures of the vacuum switch with the attached microswitches.

lotus-electrical-f38/vacuum-head-light-switch-valve-t30012.html

Unfortunately my link and part number for Allied Electronics our side of the pond no longer works so you may have to get the switches from a Lotus supplier. Try Ray at RD. If he doesn?t have them I can try and dig further. Come to think of it The Veg must have got a couple recently? From memory the originals were Burgess, but the part number was superseded. I did see someone here posted a UK supplier a while ago, maybe in the thread linked above?

HTH

Stu

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 1:59 am
by The Veg
Pretty sure I got them from Parts Express, https://www.parts-express.com/

I'm not sure that I still have the part number, but these switches are a standard item used in tons of different applications so that shouldn't slow you down too much.

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 2:40 am
by chickenstock10k
Stu, grasping at straws here but 1) is there a way to trouble shoot this with the dash in and 2) are there any better references on wiring that the shop manual, which is nearly impossible to read and not nearly as helpful as your PDF!

I am wondering if the switch got wired incorrectly, since the relay was wired incorrectly and hoping that there is a similarly straightforward solution under your lotus wiring guru-ness!

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 5:02 pm
by stugilmour
Here is a link to the part.

https://ca-en.alliedelec.com/product/jo ... lsrc=aw.ds

The original Burgess switch is NLA, and superseded by Johnson Electric Mfr's Part #: XGG2-88Z1. They are a button type switch with both NO and NC contacts.


Johnson Electric
Switch; Snap Action; SPDT; NO/NC; Pin Plunger Actuator; 15A; 250VAC; Faston 6.3 x 0.8
Manufacturer #: XGG2-88Z1
Allied Stock #: 70162365

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 5:15 pm
by stugilmour
This looks like the one The Veg would have used from Parts Express

https://www.parts-express.com/parts-exp ... h--060-600

Parts Express
SPDT Snap-Action Standard Micro Switch
Brand:Parts Express
Part # 060-600

Standard micro switch.
Specifications:
? Current rating: 10A @ 125 VAC and 250 VAC
? Housing dimensions: 28.8 mm L x 15.8 mm W x 10.3 mm D
? Contacts: 3
? Approval: UL.


Both the Parts Express and Alied links have tech data sheets with the dimensions, and they look pretty similar. IIRC Allied is a bit of a pain to order from, so Parts Express looks like the way to go.

HTH

Stu

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 5:37 pm
by chickenstock10k
Is the piece that is actually attached to the light switch (push pull headlight switch)? If so, how should it be wired?

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 5:48 pm
by stugilmour
chickenstock10k wrote:Stu, grasping at straws here but 1) is there a way to trouble shoot this with the dash in and 2) are there any better references on wiring that the shop manual, which is nearly impossible to read and not nearly as helpful as your PDF!

I am wondering if the switch got wired incorrectly, since the relay was wired incorrectly and hoping that there is a similarly straightforward solution under your lotus wiring guru-ness!



It is tough to trouble shoot the switch further as it is just a simple switch circuit that is not working correctly. The issue is the switches are mounted on the inside of the switch, making access difficult.

That said, take a look at the thread with the good photos and you can see the two switches connected to the NO and common terminals. If you can see in there, make sure yours are connected like in the picture would be a good start. I will take a quick look at the diagram to try and describe the connnections better. IIRC my PowerPoint diagram might not detail all of the wire colours fully.

You could also disconnect the two wires from the sidelight microswitch and connect them together with an alligator clip or similar. This should cause the sidelights to come on. Disconnecting them will allow you to turn the sidelights off by pressing the rocker switch (they should not go out righ away as the sidelight relay will keep them on).

As mentioned, your switches could actually be OK electrically but just be slightly miss-aligned. Unfortunately the headlight vacuum switch assembly has to come out to correct the alignment as I think the screws are on the inside?

lotus-electrical-f38/vacuum-head-light-switch-valve-t30012.html

I assume you are using the Federal diagram (with the wires identified by numbers and the colours in a separate legend)? That should be the one for your car. It is difficult at first for sure. I used the other diagrams to figure out what he circuits look like schematically. But that is the diagram that most accurately describes the Federal Plus 2 that I think you have.

I posted PDF?s of the diagrams here. With the PDF you can zoom in to read it better, or get some copies printed.

lotus-electrical-f38/wiring-diagram-for-elan-federal-t43741.html

HTH

Stu

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 5:52 pm
by stugilmour
chickenstock10k wrote:Is the piece that is actually attached to the light switch (push pull headlight switch)? If so, how should it be wired?


Will take a quick look here.

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 6:15 pm
by stugilmour
This is the relevant photo of the headlight vacuum switch with microswitches. The original poster describes it as the stock setup.

679e18ab-30f4-42a2-85f9-b5bc4ae95c3b.jpeg
Plus 2 Federal microswitches attached to the headlight vacuum switch.
679e18ab-30f4-42a2-85f9-b5bc4ae95c3b.jpeg (68.5 KiB) Viewed 467 times


The wire colours from the Federal Wiring Diagram agree with the photo. They are as follows:

  • Sidelight microswitch has two wires, both 24 - Blue. They run directly to the sidelight switch terminals. Referencing the PowerPoint diagram they run to what I called terminal 2 and terminal 3 (which were totally arbitrary terminal numbers, but physically I think are the top two terminals on the switch).
  • Headlamp microswitch has two wires. 18 - Black/Red and 2 - Black. Black is ground. Black/Red I am not sure. I don?t think I ever fully understood the Federal diagram (there may be an error), but essentially the Black/Red should logically switch the main and dip headlight relay coils to ground when the vacuum switch is pulled out, which acts as a proxy for the headlight pods being in the up position. I believe the selection of Main (High Beam in NA Speak) or Dip (Low Beam in NA Speak) is accomplished by switching these relay trigger coils from the positive side with the column mounted dip switch. At any rate, that is how I wired mine when I fully replaced the loom. Basically for our purposes here if your headlights are working correctly just leave this microswitch wiring as it is.

HTH

Stu

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 6:24 pm
by stugilmour
Here is a copy of the technical drawing for the microswitches which shows the physical location of the common, NO, and NC terminals. Note they agree with the reference picture with the Blue wires going to the NO and Common terminals.

54c58005-b710-4934-ae4e-4d8c0b8f8548.png and


HTH

Stu

Re: Dashboard / Instrument Light Woes

PostPosted: Mon Feb 18, 2019 7:09 pm
by stugilmour
Let us know if your light switch assembly is as per the photo. I am just checking your VIN 50/1781 against the Robinshaw & Ross Production Milestones. I believe the Federal microswitches we are describing here were introduced with 50/1363. However, there is a reference to ?New headlight microswitches and mounting bracket assembly? being introduced with 50/1892. It does not say if this change effected Federal cars or non-Federal Plus 2S cars, so I am not 100% sure if we all have the same setup. Pretty sure, but not 100% Anyway, wanted to put a remark here in case someone comes across this thread a few years later and their car is different. The Federal Plus 2S was not introduced until 50/2447, so well beyond the microswitch change reference.

Regarding the Federal Wiring Diagram covering the headlight circuit, I believe it is particularly confusing as they are trying to show a couple of versions in one drawing. I can?t remember the details of the stock loom, but recall at the time I speculated that they did kind of a bodge running change. I think the pod microswitches were originally physically located at the pods, and the movement of the light pod actually triggered the switches. This is similar to some Elan setups I have seen here. Had to be this way when the pods would fail in the down position to prevent the headlights being on when down. When they relocated microswitches to the dash vacuum switch they may have left the wire runs to the front of the car. Not certain on this, but as I say I never understood the diagram fully anyway and relied on what it was trying to accomplish.

Hope you can trouble shoot your sidelight switch issue, and maybe even get the circuit working if it is a simple matter of moving a couple of wires around. However, if you do pull the headlight/microswitch assembly out, or take your dash out for any reason, I would suggest replacing both microswitches as a preventative measure. After fifty years they seem to fail. Go figure. :D Maybe even order them up as they are cheap enough.

Last little remark on the headlight microswitch. As mentioned above, the switch closing electrically is kind of a proxy for the pods being up. Remember that this revised circuit is used on Federal Fail Safe headlights only, so the pods fail in the up position. Pretty reasonable to assume the pods would be up when the vacuum switch is pulled out. Just thought of this extraneous detail.

HTH

Stu

Re: Dashboard / Instrument Light Woes

PostPosted: Tue Feb 19, 2019 12:03 am
by chickenstock10k
OK, the plot thickens...

I was able to disconnect the vacuum hoses, loosen the light switch and turn it over in place to examine the wiring. Much to my surprise, none of the wires match the posted image or the colors on the the passenger side relay. From top to bottom (in their proper position since photo is the circuit upside down) black, red / white (maybe yellow), black and red and then black again.

switch-small-flipped.jpeg and