Ken the electrical guy Q n A

i would still need 3 wires down the chassis to make this work so that the lower red led is ON both switches when the power is applied to the circuit

Top circuit is positive side switches

Bottom circuit is negative side switches.


it seems that positive side swiching in this case i simpler as i can jumper terminals in the switches to make the LEDs go on when necessary.

 

thats close. look at the bottom diagram i posted.

your way there works for the right switch but would create a full current for the left switches led to always be on.

download the attached file and open it here and see if you can't come up with a better solution than me.

 

Yes I was giving a simplified overview and yes you may need extra wires for your indicator leds or to make the circuit do what you need. I too generally switch on positive as that was what many circuits did, but that’s preference.

I missed your circuit diagram before. I’ll noodle it, but I’m not actually sure if your primary question on how to drive the relay from two places hasn’t been answered, and not sure if your preferred switches are both DT and isolate the indicator.

 

yeah, i guess everything has been answered. i was curious if there was an easier way to go about things as i'm no electrical engineer.

 

Hey Ken, do you do only Tacoma's? I have an 82 pickup and I've been trying to do a couple of things.

 

No I work on almost everything. I have done a lot of work with classic vehicles. Not saying that 82 is that old but you get the point. What’s going on bud

 

One of them is my vent/heater fan. It has 4 positions. Off, low, med, and hi. Off, med and hi work fine, but low doesn't work. I hear the relay clicking, but the fan doesn't spin. I can't figure out what's wrong.

The second one is my horn. It is getting a consistent 12v, doesn't matter when it's switched off. I have no idea if there is a relay or not, I haven't found one. I've gotten numerous answers, never gotten a clear answer. I've done the 22lr casing trick when the "connector" (lifter?) gets worn down. I can't get pictures right now, but I can later this week.

Thanks!

 

If the horn stuff is fubar'd, I have a seperate wiring harness for the horn specifically that i can hook up to the original switch.

 

with most things the first thing you’ll want to do is get out your multimeter and do some testing. Locate your blow motor relay and set the switch to the low position. Insure that you have voltage to both the 87 and 85 positions while the fan is on low. If you are getting voltage at these points we know the switch is sending the trigger voltage. Next I would check on the ground for the fan alongside the positive connector. I’ve observed a connector that looked as if it was mated but actually cocked to the side. At low settings it didn’t have the right contact to work. When you kick up the load it would “bridge” the gap and function but with low loads it wouldn’t work. So look for loose connections that power and ground the fan and possibly bent terminals inside the connectors.

after we know the ground is good and the connections up to the fan are good. As well as the relay is functioning as it should I would be suspicious of the fan having an internal issue at low load. I’d do some bench testing of the fan. There should be an internal resistance of the fan from the manufacture and you can get that number. Sit the fan down and hook some alligator clips to the leads. Test for ohms and see what you get. However unlikely, what ever remains must be the answer.

There’s another very rare possibility but I’d try what I mentioned above then if all that fails well move forward.

With regards to your horn.

First determine if it indeed has a relay. I would assume that it does but depending on the year they could have directly wired it to your switch (horn). If you do not....have a relay your horn button switch is sticking internally and you will need to replace it or take it apart and inspect. The only other thing that it could be is that something is tapped into the horn circuit and is a backfeeding a constant 12v load to your horn.

If you do....have a relay the above issues are possible. Additionally relays can get stuck. I’ve observed relays that have gotten stuck in both 87 and 87a position. I would pull the relay and see if it stops. If it does...replace the relay and you should be good. If you replace the relay and it does not stop...then you have a trigger wire issue...


I hope this helps you and if you don’t get anything I said please let me know and I’ll be glad to help anyway I can.

 

Thank you so much for your insightful help!! I will get back to you how things go!

 

Keep me in the loop we’ll figure it out

 

I was wondering if someone could help me figure something out. I have wired up 2 sets of Hella lights on the front of a 2013 Tacoma. The lights are working as they should without any issues. The issue I am running into is the switches themselves are not back lighting like they should when the headlights are on. The back light is so dim you can barely tell it is even on. The climate control panel (which is where I pulled the illumination wire from) is also very dim. It has been a little while since I have messed with it but the time has come to fix the issues. Can anyone explain to me why the back light of the switch and climate control would not be working right and would be so dim??

Here is a link where I bought the switch:
https://www.aironboard.com/online/p...em-replacement-sasquatch-lights-led-blue.html

Here are some just basic pictures of the wiring and final product:


Any help would be greatly appreciated!

 

Turn on the headlights and test the wire you used to power the led for the switch for voltage. Tell me what u get and we’ll move forward from there

 

Hi Ken,

Would it be alright to ask for help here in this thread regarding one of my horns not working? Didn't want to go into detail since this is a "project" thread, but its killing me that my low tone horn doesn't work even after swapping it with a replacement. Looking for advice on how to start troubleshooting.

Thanks! Great thread!

 

This thread is basically for anyone who wants help with electrical stuff buddy. Please ask away

 

I will try to get that reading later today. Here is the wiring diagram for the switch. Are Tacoma's positive switched or negative switched? I have it wired as the positive switched diagram.

 

Alright so here is a color coded wiring diagram I drew up after doing some research. I need to check my connections but let me know if anybody sees anything wrong with the drawing.

 

How did you wire the light circuit for the switches?

I ask because the dash panel light circuit on our trucks uses a separate ground, not the chassis ground.

When I wired in my switches, I tapped both the + and - circuit from the HVAC control panel for the switch illumination lights.

IIRC, the in-use light on the switch required its own ground - in that case, a chassis ground.

I am going off of memory, so I could be slightly mistaken...

I can check my wiring diagram this weekend.

 

I really appreciate it. My low tone horn does not work. I replaced it thinking the horn itself was the issue after verifying it wasn't the fuse, and knowing my spiral cable was replaced prior to this issue. So, upon installing a new horn I still don't have the low tone (i.e. only 1 of 2 horns is working)which is why I believe it is an electrical issue of some sort. Below is the wiring diagram for the horn(s). I have electrical tools to help diagnose and repair so if you agree its an electrical issue, where should I start?

 

hey @Kens04Taco - I have an 05 tacoma, i have converted my turn signal lights to running lights and i want to make them pulse as turn signals also. do you know of a way with out running two relays? I believe if i went the two relay route i would need normally closed relay and i would use the actual turn signal wires to interrupt the ground wire to the running lights. im curious if there is a dpdt normally closed relay available so its less wires.

Thanks