electrical issues. no signals or hazards

[supra_fast]

I have a 1991 toyota supra tt-r jza70. It is fairly new to me as a car but not as a supra. i have owned multiple supras over the last 10 years. 7 to be exact. this is my third 1jz. I bought it for a pretty decent price because it had a couple issues. I cant figure this one out but im no mechanic or electrician.

issue:

my signal lights dont work nor do my hazards. i checked the fuse and it was blown. i replaced it and then tried the hazards and it blew that one. I put a slightly bigger fuse in just to see if it would hold. I was not going to leave it in weather it holds current or not. this was just to see if it could help me diagnose this problem. It did hold current, so i try my signals and still nothing, not even the clicking sound you normally here. I tried the hazards and i heard the clicking sound. so i went to see if they were flashing. At first i didnt think they were but when i got closer, like really really close i caould just barely see them flashing. every light on the right side was flashing but all of them were very dim. none of the lights on the left side were flashing, at least that i could tell. when i went back in the cab to turn off the hazards there was a tiny bit of smoke coming from where my deck is supposed to be. ( I dont have a stereo in it right now so its just a empty hole right now.)

Any ideas?







i used a tone generator to follow it but its a really crappy one i think im just losing signal. I followed it under the rad support and out the other side and then it dips down and "y's" into the fender and the other wires look like they loop back up into the engine where the spark plugs are. doesnt look like there could be a break where it stops making noise. it stops making noise right around where it "y's." does the hazard wire go into the fender or stay in the engine bay? they were not working when i bought it and i asked the guy i bought it off of if they stopped working after doing some work. he said they were working fine and then he parked it for the year and they stopped working. he was not doing any work.

 

[hvyman]

First never put a larger fuse in.

Second the turns won't work without the hazard switch and based off the smoke is start there since it's prolly burned now.

 

[supra_fast]

Ok but when the larger fuse was in and the hazard were flashing i still wasnt getting anything from the the signals.

 

[f00g00]

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=070
Http://supra.co.nz/2013/jza70/jza70tewda.pdf
use the tewd for wiring trouble shooting.
You can also compare it to u.s models.
There is a reason for fuse ratings and wire guages.

 

[supra_fast]

I think im supposed to be looking at page 112 but as you can see i dont have a spot for a 7.5A fuse or is that fuse located somewhere else?

Travis

 

[hvyman]

I cant really see in those pics but there should be 6 fuses in the bottom right where the head light fuses and the efi fuse is.

And stop putting larger fuses in and ignore you even did that. Its not a valid process to diagnose and your going to fry something.

 

[supra_fast]

so i found the signal fuse. i didnt realize it was located inside the car by the feet of the driver. the 7.5A was blown as well.
2 questions

1. I was following the wires and found out the horn ware was disconnected. is it possible that the horn wire may have ground out and caused both fuses to blow?
2. when i replaced the signal fuse only the left side started working. when i switched to the right, it made the sound but none of the lights came on. Does all the lights stop working if only one light is out?

Thanks

Travis

 

[hvyman]

Depends which horn wire. If its the ground side for the switch no. If its the power wire yes.

And if a bulb is out the blinker will be blink fast or have the the light on the dash for a light out.

The whole right side not working is most likely the hazard switch or the turn signal switch.

Flip the hazards on and if only the left side works replace the HAZARD switch.

 

[f00g00]

The horn on the firewall or the horns near the hood latch?
Have you pulled the flasher switch and made sure its fully plugged in? That is probably what got smoked.

 

[supra_fast]

the horn near the hood latch. i did a current test and it was the ground.

I went out and bought the right fuses. i put in the 15A for the horn/hazard and it holds even if i use the horn but the second i hit the hazards it blows. I also replaced the 7.5A for the signals and it holds fine when im signaling right (which is the same side the hazards work on) but when i signal left it blows. havent checked the flasher. next step is a new hazard switch. is there a way to test the switch to see if its bad using a multimeter?

 

[supra_fast]

I think i learned how to do it. from what i read is that the higher the ohms the more resistance. switches should have zero ohms. These are my resaults





i drew out what the prongs looked like and connected the ohm meter to each of the prongs one by one. i drew a line connecting which 2 i touched and what the reading was. the top right number says 23.9. i double checked and then triple checked. floated right near that number.

Bad switch?

 

[hvyman]

ITS ALL IN THE MANUAL.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=BE&P=26

ALWAYS BEST TO LOOK IN THERE FIRST.

 

[supra_fast]

Im not really sure how to translate that. when the switch is on am i supposed to check 1,2,5 and 8 all at the same time? on the third line where is has 3 and 10, what is the circle in the middle of 6 and 7 mean?
also, says nothing about ohms in there. 23.9 ohms is to high correct?

Thanks for your patients

travis

 

[hvyman]

Your 23.9 ohms i have no idea of what pins you were touching so.....

No you should have continuity between all 4 of those points. Theres only 2 leads so if you touch any of those you should have continuity but it wont be much if any.

 

[3p141592654]

On: Pins 1,2, 5, 8 are connected together. Pins 6 & 7 are connected.
Off: Pins 7 & 9 connected.

I think 3 & 10 are the switch illumination light.

Applying 12V to pin 8 on the body connector should illuminate the LH lights, and pin 5 the RH lights. Make sure you fuse your jumper if you are going to try that test.

 

[supra_fast]

when i touched pins 1 and 8 together i got 24 ohms. when i touched 2 and 5 i got 5.5 ohms. pins 2 and 8 had 3.4 ohms and the rest have almost no resistance. from what i read and watched on youtube, switches should have no resistance. if they do the switch is bad. i am just seeing if anyone can confirm. ill check for continuity tomorrow although im sure it will have continuity because its not a broken circuit but just has resistance.

 

[hvyman]

24 ohms is too much. should be less than 1. . 3 .4 max. repalce the switch.

and DONT put a bigger fuse in again.

 

[3p141592654]

Actually looking again I think it is pin 7 instead of 1, but anyway 24 ohms is too high and would explain why the LH lights are dim. Doesn't explain blowing the fuse though, unless other weird things are going on in the switch. I would strongly suggest checking out the LH circuit because if it is shorted the new switch will also be destroyed.

 

[supra_fast]

How would i go about to check that circuit?

 

[3p141592654]

Applying 12V to pin 8 on the body connector should illuminate the LH lights, and pin 5 the RH lights. Make sure you fuse your jumper if you are going to try that test.