Assistance with Car Folding mirror project

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Thread Starter


Joined Feb 28, 2012
I found some very helpful threads on here that were similar. I do apologize in advance, like many posters, my electrical knowledge pales in comparison to most of yours. Which is why I'm here looking for help :D
here's one thread that is the most similar to my circumstances:

With my situation being different, I was unable to get my answers from the other threads.
This is a long Post, I didn't want to leave anything out, so bear with me to get this started :)

Here's what I have going on:

I have 2 folding mirrors, the DO have built in limit switches (current switches I think actually but it's not important).
This was good news to find out because it simplifies my wiring.

(I will be uploading the diagrams I've roughly drawn up as soon as I'm home, I cannot upload from this computer)

I have an OEM folding mirror SWITCH too, but no diagram for it so I had to test it out. It seems the following is true for it:

Terminal 1 = Output to Mirror Motor (+/-)
Terminal 2 = Output to Mirror Motor (+/-)
Terminal 3 = Ignition Power +
Terminal 4 = Constant -

There are 3 switch positions with no spring return to neutral. One is FOLD OUT, one is FOLD IN, and then NEUTRAL
Obviously FOLD IN and FOLD OUT alternate consistant power/ground out to the Mirror Motor terminals. And Neutral seems to be isolated completely, this was good news also.

So now you know what I have for a SWITCH and for an OUTPUT already. Here's what I want to acheive:

When I press the LOCK button on my Key Fab, the mirrors fold in.
When I turn the IGNITION to "ON" the mirrors fold out.

I plan to keep the Folding Mirror Switch in the NEUTRAL position at all times during the uses listed above. If it's left in either FOLD OUT or FOLD IN positions on the Folding Mirror Switch, then obviously I could have a Short due to reversing polarities. I plan to fuse/circuit breaker both outputs to the Motor as added protection of course.

What I've considered so far:

Using a N.O. Latching Relay for the LOCK function. This would allow me to press the LOCK button only once (pulse) but have the mirrors fold in all the way. The issue with this is I don't know how to RETURN the Relay to the N.O. position, I'd assume that I need to run another trigger from the IGN "ON" relay to trip it back to N.O. state BEFORE it sends power the other way. I also though about using a NOTO Relay with a timer around 10 seconds for this function. Unsure if this is best?

This one I'm kind of lost on. At first it seemed simple, a standard SPST relay should work, but this poses an issue with the normal "manual" function of the switch. If the key is in the "ON" position, then the Folding Mirror Switch is powered also. This is an issue I'm not sure how to overcome, because the Folding Mirror Switch is a fairly sealed unit.

Before I suggest ideas on overcoming this, I will rather humble myself, and put it to your suggestions. You likely have a much better and simpler Idea for this issue than I.

To sum up, my issues/questions:

LOCK (FOLD IN) FUNCTION: Need to determine the proper/ideal "latching relay" or "timed/holding" relay, or other suggestion to control pulse signal. Is a NOTO SPST relay with about a 10 second time best?

KEY "ON" (FOLD OUT) FUNCTION: Running a standard SPST relay for this AUX function poses an issue with the normal "manual" function of the switch. If the key is in the "ON" position, then the Folding Mirror Switch is powered also.

I found 1 unit that seems it may work for both functions, but I'm unfamiliar with it:

And also a bunch of wiring options here, but I'm kind of unsure which suits my application best, if any:

Of course, your help is very much appreciated. I was hoping to finish this project this weekend, but this electrical hurdle has me scratching my head.

Thanks in Advance guys!
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Joined May 23, 2009
Rear view mirrors are a vital safety feature of any automobile, not a good idea to mess with them, OEM or aftermarket, if a malfunction occurs you could risk an accident.


Joined Jul 17, 2007
Our Terms of Service has changed since that thread; paragraph 6 reads:

6. Restricted topics. The following topics are regularly raised however are considered "off-topic" at all times and will result in Your thread being closed without question:
  • Any kind of over-unity devices and systems
  • Automotive modifications
  • Devices designed to electrocute or shock another person
  • LEDs to mains
  • Phone jammers
  • Rail guns and high-energy projectile devices
  • Transformer-less power supplies
As your topic definitely falls in the "Automotive Modification" category, it is outside the scope of these Forums, and thus cannot be discussed further here. The Terms of Service was written by the website owners, and the rules are not up for debate. I hope you understand this, and will abide by the rules.

I will also discourage you from attempting this modification; as hwy101 mentioned, mirrors are definitely safety equipment.

If you feel that you absolutely must attempt this modification against recommendations, there are other forums where you might discuss such projects; a short list of forums is in this thread:

Thread Starter


Joined Feb 28, 2012
Thank you for steering me in the right direction. This is a common option from OEM manuafacturers, and my purposes for posting are to ensure that I go about it in the safe way, to OEM standards, and thusly, DOT standards as well. I do not want an unsafe vehicle, nor is that the purpose or scope of this modificaiton. I will delete this thread once I transfer the post, thank you again for your help!

EDIT: I'm unable to delete this thread myself. I'm sure a Mod will come across and delete it shortly. thanks again.
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