No start after pulling the mir relay.
 

Car won't start after I accidentally pulled the mirror heater relay. It shut off as soon as I pulled it. I was trying to diagnose a cooling fan issue and I pulled the wrong relay. All the electronics work except the starter doesn't even click and there dash doesn't illuminate other than the door open light. The supercharger coolant pump also won't come on. Fuses all show continuity (except one of the fan fuses but I replaced that one)


No fuel pump noise
No CEL
No Link on an OBDII scanner
Dash doesn't "Wake Up" when turning the car on.

Did you check that big fuse that's up on the battery?


humfrz

I did. Looks ok. Both bolts off the post have continuity. Also the headlights and radio are fine...

Does the starter have a relay? (I don't know)

If it does, did you check it?

humfrz - ain't much help - :sigh:

link to wiring diagram


check the 10A ECU IG1 7.5A MPX-B 15A HAZ 10a ECU ACC fuses they common to mirror heater and dash imobilisier

Thanks for the reply. Just went out and rechecked. All of those fuses look fine, have continuity across them and have 12v on the volt meter against a ground. (Battery ground or bolt in the door jamb)

I am old school, so I would disconnect the battery for a minute. This could reset the car.


When I unplugged the ABS fuse; I had to disconnect the battery cable to have it recognize that I had plugged the ABS fuse back in.

You need another person to start the car and while they are doing that check to see if you even have power going to the starter wires...

OBDII scanner says "No Link"

did I brick the ECU?

Ya, i left the negative side off overnight hoping... no dice.

I'm sure it's not just power to the starter. Too many other things don't work. With the key "on" but not turned to crank it doesn't even wake the dash up with the engine light and all that.

It kinda sounds like an ECU problem although I'd be rather surprised if pulling a relay would brick the ECU completely. You said the ECU fuse(s) are all good? Did you put a meter on them or just visually look? Sometimes fuses are bad even if they dont look it.

There is a fusible link in that circuit for the alternator.

The issue I have is that removing a relay shouldn't blow any fuses whatsoever.

I'm assuming you have a multimeter, so do this. Put one lead on the battery positive terminal and the other on the power wire of the alternator and let me know what it reads. (Have it set to DC volts)

I put a meter on them, visually inspected them and checked both sides of the fuses for 12v... all checked out ok.

Is it a pushbutton or key start?

Found my better "beeping" multi-meter. Just went through all the fuses under the hood and in the foot well again, all have continuity.

I don't follow wiring diagrams well... if the mirror heater relay broke when i pulled it would that kill the power to the ECU?

I have an FRS, the red "car and lock" is flashing and the door ajar is on. When I insert the key the car and lock light goes out. Door ajar works as you would expect. Nothing else on the dash works.

Radio works, headlights work.

Betting on a trip to the dealer...

No, it's a '13 FRS.

This might be a stupid thing to ask but I'll ask it anyway, if you have an Auto Trans are you in Park or Neutral. Just remembered a similar thing happened to my brother awhile back

12.57.

Nothing is stupid. It's a stick. Problems are obvious before I ever trey too crank it.

What is the exact volt reading on your battery??


Is the battery the original battery?


Sometimes a weak battery will cause problems.


Before I'd take the car to a dealer, I would take out the battery and take it up to a shop and have it "load tested".


humfrz

So from battery POS to the power wire from the alternator, you have a reading of 12.57V?

Normally I would agree but the car was running, i pulled the relay and it died. I think something is broken...

If you did your testing right, I know what the issue is.

Just need you to confirm.

I have to get back to work, but if you did what i asked for testing, you have blown the fusible link (pic below). Remove the cover for the positive battery terminal and look in the glass and see if the elements are separated, if so, you have found your issue.

Worth adding that if you blew this fusible link, you would no longer have ignition power, etc. So it sounds like that is probably what happened here.

https://www.ft86club.com/forums/atta...1&d=1425254264

Looking in the wiring diagram the only thing tied into the mirror heater is that big fuse on top of the battery.

You should be able to talk to ecu via obd port (ie can buss) with just earth 12v and ignition 12v supplied to ecu.


Check all ecu fuses

I checked that and they look ok. I also have continuity between the battery post and both of the big nuts that have blue lines in your image.

I put the meter leads on the big bare starter bolt and the positive terminal on the battery. I didn't really expect 12v, i assumed it was + to +. Maybe i hit the wrong part of the starter.

Alternator bolt and battery positive. It is positive to positive, but it is called voltage drop testing. Easy way to determine if a fuse/fusible link is blown without visually inspecting it.

A meter tells you the different between the two leads. If you go positive to positive and show a difference of 12 volts, it isn't making it to where it should be.

Yes, it's clear to me the car is missing either

12v to ECU
switched 12v to ECU
a functional ECU.


I did have an OBDII dongle plugged in at the time. Maybe some black magic sent full voltage across OBD pins that shouldn't have?

I don't have a setup to test the ECU externally from the car.

Oh DUH Obviously... so I was right not to expect voltage.

The radio, headlights, locks and windows all work. I wonder if they come off the other side...

Doing more digging but if either of those links is blown i shouldn't have continuity to those nuts right?

Right, if it was operating normally, you would expect 0 volts, as there is no difference between the two.

And yes, if the fuse is blown you would see a 12v drop at the fuse.

https://i.gyazo.com/da16bad6709e5fde...75d169e099.png

Going over the wiring diagram, the only thing really affected is the alternator fuse (ie, the fusible link on the battery positive block)

a video is worth about 10,000 words.

[ame]https://www.youtube.com/watch?v=zZoeBcdFhCA[/ame]

I don't understand why i would see 12v to that post on the starter from the positive battery terminal BUT there is definitely continuity across the links. Testing to each nut shows no voltage and the continuity tester beeps and goes to zero.

Resistance (continuity testing is best done with things unplugged as it sends voltage out of the meter, this can damage the ECU, it usually won't though, so no worries), but that confirms the fusible link isn't blown. And a visual on them in the video agrees.

Hmmm, not sure where to go from there...

Also worth mentioning. The bolt you were showing was the starter, not the alternator. But that isn't needed anymore, so don't worry about it.

Jeeze... my issue is reading comprehension not mechanical prowess. I TOTALLY know the difference between the alternator and starter. Everyone else in the thread has been talking starter so my brain just flipped your "alternator" request to "starter"

I think i'm getting too old and/or tired to work on cars.

Can you take a picture of the underhood fuse box, relays and all?

Sure can. I do feel like maybe I put it back in the wrong place but other images I've looked at seem to have the relays in the same place.

You are missing the ignition 2 relay, I don't know where it is, but that is 100% your problem.

https://i.imgur.com/YJtvSp6.jpg

You must have pulled another relay, there isn't one in the wrong place that I can see. Maybe it is on the cowl or inside the car? You can always move the mirror heater relay into the ig2 spot and make sure everything works.

I think that's a BRZ thing for the push button start. I thought it was weird that that was missing but I definitely didn't throw a relay away.

I'll try it... i think the fan relays have 1 extra pin.