So here is the next stage taking us up to Christmas :
Light pods and headlights not working so where to start
Spent lots of time checking the wiring diagrams trying to understand how everything works, and realised that I could perhaps test the motors with a direct 12v connection.
This is actually quite easy - disconnect the 3-pin connector and pop the motor wires out through the big hole in the bottom of the light pod. The earth is the black wire (middle pin). The live is the red & green (RH pod) or red & slate (LH pod). 12v across these terminals should run the pods up and down continuously. And sure enough my motors seem to work fine
.
So then, what to do next
Initially the motor control seemed quite complicated, but I finally worked out it's a bit like a light in your house with two switches. The headlamp switch in the cabin is one switch, and the motor position switches are the other one.
So :
1. With the headlamp switch off (or sidelights only), there should be power to the motor relay(s) in any position except when the pods are down.
2. With the headlamp switch on (full dipped), there should be power to the motor relay(s) in any position except when the pods are up.
3. The flash works on a similar principle - i.e. turn the lights on just long enough to move the pods off the down switch. They will then continue moving until the pods are down again if the dipped beam switch is off.
I appreciate there is slightly more to it than my simple diagram, but hopefully it helps to explain the way they work for somebody who is starting out on these and scratching their head.
I could hear the relay(s) when reconnecting the battery with the pods up, so knew there was power getting to the switching side, but a voltmeter on the power side showed no main power to the relay. At this point I had still not removed the pods and was hoping not to have to. I decided to make up 5 wires with spade connectors on each end to enable me to test different scenarios. This seemed like a great idea, but just served to confuse me even more as I could not get anything to work. I subsequently still think it was a good idea as it's helping me test other things :
After more head scratching, and a look at the big connector under the glovebox (all clean and dry), I finally decided to take the pods off for a better look. The hinge bolts were very tight/seized, hence my initial reluctance to take them off. They eventually came free after a couple of soaks with WD40 tbf (sorry Dave
). Removal of the pods would also enable me to check out the horn.
What I found was that my testing was somewhat flawed as I was testing the wrong things, and hence expecting the wrong results, and getting nowhere !
Here is the diagram of the relay positions which I took as gospel while testing, but I have since noted the real relay positions by hand !
This is how I discovered the error - I assumed there must be a bad connection(s) under the relay block, so did some investigation.
The two big purple wires should go to the rear connection of the RH headlamp motor relay, so something was clearly amiss.
The single purple wire should go to the front connection of the flash relay.
I then realised that, where I was expecting continuity, I was testing between things that clearly weren't even meant to be connected
.
I'm not sure what made me finally check it, but I then discovered the headlamp motor fuse was blown as well
.
I replaced that, and now having worked out which relay is which I could test things properly - all now seems to work as it should, including 12v to the headlights (both main and full beam).
But why did the fuse blow in the first place, and why did the pods and lights not work initially ?
You may remember that the headlamps were stuck in the up position when I go the car. I manually wound them down when I was thinking of going out for a test drive. They then came up when I was checking out the lights, but have not worked since, except when I manually connected them.
These are the problems I diagnosed :
1. Flash relay seized in the on position - this prevents the pods from going down.
2. Headlamp switch connection is poor in the dipped beam position - it works consistently when the headlights are disconnected, but is intermittent with the headlights reconnected and fitted back in the pods.
3. Motor overload when the pods reach full opening causing the fuse to blow.
Additionally to all the above, the pushrod/spring/pivot mechanism connecting the motor cranks to the pods seemed poorly set up (springs not seated properly etc).
So final stage before re-assembly was to disassemble, clean, re-assemble and re-set up the pod mechanisms.
My objective was to make the movement smoother, and to reduce the load on the motor by reducing the compression in the springs and minimising the length of the push rods to reduce the "over-lift" at full opening.
I also lubricated the pod hinges and got the rotation as free as possible. I still can't get over the way Lotus use rotation along a thread for the bonnet and pod hinges
. I'm amazed it works at all !
Dismantling the pod mechanism meant I had to set up the pushrods to get the home position right, but that's fairly easy, and quite satisfying tbf. Well worth the effort to be sure everything is optimised.
A bit of advice here - there is backlash in the system, so don't forget the headlamps add weight. When you test without headlights the pods will sit higher than when they are in.
Result is a slightly low home position
So, just need to refit the bonnet and wait for a dry day to go out on the first test drive
Also, will need to do a bit more work on the dipped beam switch. I'm pretty sure I improved it by switching up and down multiple times (advice from Dave at Lotusbits that this might work if I'm lucky), but it's still not completely right. Through this process I realised that poor connections sometimes only show up under higher load (more current), but not when the load is small (lower current) e.g. when the switch is operating a relay. That's definitely true of my headlamp switch.
One of the rear fog lights now works as well as the fog light switch warning light - it seems the rear fogs will only work when the dipped beam is on. So only one rear fog light to fix and I will have a full set of working lights
.
I'll re-adjust the pod position to be spot on flush when they're closed soon.
Some of you may be thinking I forgot the horn - fear not - I did test it before putting the pods back using the same principles as when I tested the light pods - direct feed to the horn itself proved that works ok. Then power to the relay block on the horn side proved that the connection from the relay block by the fuse box to the horn is sound, as I could manually operate the horn. The horn still doesn't work from the column switch, but at least I know the problem is in the cabin now, not in the light pod or front loom.
A final note - I'm pretty sure the crank on the RH pod motor is longer than the LH one, hence putting higher load on the motor, especially in the "overlift" phase, and probably contributed to the blown fuse. I'm wondering if this is because someone has fitted a motor from a non-Lotus car that is perhaps nearly the same ? Has anyone else experienced anything like this ? I know Dan said he used (or at least considered using) a TR7 pod motor.
Cheers All,
- I put it on the "alternative parts" thread under steering gaiters.
