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Miata/MX5 headlight retractor motor wiring

PostPosted: Sat Aug 06, 2016 1:48 am
by prezoom
There have been several posts on replacing the vacuum actuators with Miata/MX5 headlight retractor motors. I am now joining the crusade and am asking for a little assistance in how they were wired. My Plus2 S13) has a power wire that operates the vacuum switch, via the headlight switch, what did you guys do to connect the power to the 5 wires that are part of the motor wiring? Trying to avoid the long slog through wiring diagrams, etc., to make this motor work. Any short cuts would be more than welcome.

Re: Miata/MX5 headlight retractor motor wiring

PostPosted: Sat Aug 06, 2016 5:30 am
by john.p.clegg
IMHO,others may disagree...

Easiest route is to take a "tap" off the wire from the headlight switch to indicator stalk ,this is live only when main/dip is selected,use this to power a change-over relay,operated is up,released is down.

John :wink:

Re: Miata/MX5 headlight retractor motor wiring

PostPosted: Sat Aug 06, 2016 11:59 am
by mbell
On mine I wired a change over relay using the solenoid wiring as the input signal. This provides the up/down signal to the motor based on the light switch.

Power came from the alternator connection, via a relay connected via a switched live. I also added fuses and relays for the headlights while I was there, all in a mini fuse/relay box.

Re: Miata/MX5 headlight retractor motor wiring

PostPosted: Sat Aug 06, 2016 2:43 pm
by prezoom
I had planned on using the solenoid power lead, with a relay. What I am after, is there are 5 wires out to a connector, and what to do with them. I would think the red wire is probably the main power lead, and black should be ground. But, what about the others?

Re: Miata/MX5 headlight retractor motor wiring

PostPosted: Sat Aug 06, 2016 2:46 pm
by john.p.clegg

Re: Miata/MX5 headlight retractor motor wiring

PostPosted: Sat Aug 06, 2016 7:18 pm
by dougal9887
In my experience there are no shortcuts!
Towards the end of this post re. my installation, you'll find a .pdf wiring diagram. This allows the operation of the motor to replicate the original using existing switches and including the flash functionality of the stalk. I also added a concealed switch to lift and lower the pods with lights off for washing etc.
elan-mods-f31/electric-headlamp-conversion-t33458.html
Dougal.

Re: Miata/MX5 headlight retractor motor wiring

PostPosted: Sat Aug 06, 2016 10:46 pm
by stugilmour
prezoom wrote:I had planned on using the solenoid power lead, with a relay. What I am after, is there are 5 wires out to a connector, and what to do with them. I would think the red wire is probably the main power lead, and black should be ground. But, what about the others?



Rob, I posted a PowerPoint Diagram in the thread below, and have re-posted it here. I was looking it over again and I am confusing myself. :D Hopefully a wire connection list will sort both of us out. :)

lotus-electrical-f38/headlamps-t19721.html

Although I used Toyota sourced motors, I believe the wire colours were similar (if not the same) as the Miata motors based on the various wiring diagrams folks have posted. The Toyota wire colours changed at a connector, but I believe the wires on my actual motor assembly are consistent with the Miata. In any case, you can easily use your ohmmeter to check out the three signal wires and compare to the PowerPoint pictures to find the up, down, and common wires.

With that caution, to get you started my motor assembly wires are listed below. Note with this configuration the relay switches the motor power and the rotary switch only sees the milliamps required to switch the relay coil, hence the smaller three wires to the rotary switch.

  • Red - Main power to motor. (Seem to recall it was a larger gauge?). Gets connected to relay terminal 30, which is the common terminal of the relay switch.
  • Black - Main Ground from Motor. (Seem to recall it was a larger gauge?). Gets connected to a body ground.
  • Blue - Down signal to rotary switch. I used a Normally Closed (NC) terminal on my headlight switch microswitches, which is an attribute of my Federal Plus 2 car; YMMV. If you do not have this NC terminal (i.e. it is hot when the lights are off, and off when the lights are on), you will need a second change-over relay, which I think I added to slide six in the PowerPoint. Again, this is a signal to the relay coil, so not a big draw.
  • Yellow - Up signal to rotary switch. This is connected to the light switch hot wire you had in mind. Again, it is a signal wire so not a lot of current.
  • Green - Rotary switch common i.e. This switch wiper is always in contact with the metal rotor, and is basically the output signal from the rotary switch that activates and deactivates the relay coil. This gets connected to terminal 86 on the changeover relay.

Here is a summary list of the relay connections:

  • 30 - Relay switched common - The main pod motor power wire (Red)
  • 85 - Relay coil - Chassis Ground (Black)
  • 86 - Relay coil - Rotary switch output (Green)
  • 87 - Normally Open (NO) changeover relay switch contact - Hot at All Times Fused Power Supply (Typically Purple in Lotus). This becomes the power supply to the motor when it is raised or lowered; I think I used a 15 amp fuse.
  • 87a - Normally Closed (NC) changeover relay switch contact - Chassis Ground (Black). If this is not grounded, the motor may continue to spin (if there is enough momentum for the signal wire wipers to skip over the gaps in the rotary switch plate). I only really had this issue bench testing the motor; with the pods connected it is pretty hard for the motor to keep going past the gaps. The motor only runs when the relay is activated, and as soon as the wiper hits a gap in the rotary plate the relay deactivates, the motor sees ground on both terminals, and it dead stops.

For connection and operation details, take a look at the PowerPoint diagrams. Note the diodes shown in the pictures are already inside the motor and rotary switch assembly, you do not have to add them. I was getting a bit confused with my PowerPoint slides as I should of had the relay activate and de-activate in the pictures (i.e. move the switch symbol) based on the position of the rotary switch, so you have to use a bit of imagination I guess. Basically the motor only moves with the relay activated, and the two gaps in the metal rotor cause the motion to stop until it is signaled again. The internal diodes keep the circuit from back feeding.

With this setup, if you manually turn the motor rotary switch with the knob, the motor will start turning until it cycles to the down position. WATCH YOUR FINGERS; THE MOTOR IS VERY POWERFUL. I see in the other linked thread of Dougal's installation this is common with the stock Miata set-up.

Also with this setup there is no parasitic loss due to activated relays, and the pods always return to the down position when the lights are turned off, whether the car is running or not. I considered but didn't bother with a Flash to Pass or a separate pod up switch. I connected Flash to Pass to my driving lamps and I just turn on the lights when I want to clean them.

Let us know how you get on. The wiring is really more confusing to describe than to try out and do. Suggest trying and testing it outside of the car to confirm the connections.

The mounting of the motors is also an interesting topic and challenge. I used some sort of fence bracket I found wandering around Home Depot as a mount, and one of the stock Fail Safe springs. :)

HTH

Stu

Re: Miata/MX5 headlight retractor motor wiring

PostPosted: Sun Aug 07, 2016 1:27 am
by prezoom
Thanks everyone. While waiting for your answers, I started machining a new bearing retainer for the front of the gearbox to mount the coaxial throw out bearing. When I finish getting that sorted, I had already made one based upon the close ration box I had on the bench. However, the mid close that came out of the Plus2 is a bit different in the seal area, so I decided to make another to match the later gear box. I will dive into the headlight operation as soon as I finish making chips. Will post back what I learn.