Electrical Gremlins on the attack!! (1 Viewer)

[bhicks]

So the new (to me) 80 has been working through some electrical issues. I feel like I'm playing "Wack a Mole". I fix one thing and another immediately pops up. Here's the super quick condensed run down. When I first got the 80 the dome lights didn't work. I have door lights and the light on the dash comes on when the doors are open BUT no dome lights. New lights got installed but no fix. Checked the connectors and each overhead box and are all good. Went to use my 12 volt compressor the other day to check out the air mattresses for camping and the 12 volt plug has no power yet it did a few weeks earlier. I poped the hood and checked the Dome light fuse first. When I went to pull the fuse it started sparking. As soon as the fuse starts to go in or out the fuse sparks. When it sparks my clock on the dash goes out. I reset the clock. Also installed the new fuse. Then this morning after the new fuse is in and the clock was reset I realized my antenna isn't going up or down when the stereo comes on and it did before. I also have horrible static now on radio stations that were clear before. What the hell!!! How can dome lights mess up my clock and stereo? Right now my clock, stereo, dome lights, antenna, and 12volt cig plug are all messed up. The 12 volt plug and dome lights are totally dead. The stereo, clock, and antenna are spiratic. I checked the common grounds I am aware up and all is good. Any help would be much appreciated. I'm loosing my mind and it's super frusturating that things are failing instead of getting fixed.

 

[pengfinn]

Check the dome fuse, I believe clock, dash, and dome are on that same circuit.

 

[McDowra]

I would recommend running a new wire to the cigarette light with its own separate fuse. The wires from the factory are too small and this also will make the lighter hot all the time.

 

[BILT4ME]

Check all your body to ground cables. I think there are 6. There are a couple under the hood, some under the middle and the rear.

 

[bhicks]

Check all your body to ground cables. I think there are 6. There are a couple under the hood, some under the middle and the rear.

I didn't find 6 grounds. I found 4. I will look some more tomorrow. Thanks for letting me know the number.

 

[bhicks]

Check the dome fuse, I believe clock, dash, and dome are on that same circuit.

I actually did replace it. That was when I got a bunch of sparks and the clock and antenna took a dump. Never seen that before with a fuse. I know sparks shooting out of a fuse block is bad, but no idea what would be causing it.

 

[pengfinn]

I actually did replace it. That was when I got a bunch of sparks and the clock and antenna took a dump. Never seen that before with a fuse. I know sparks shooting out of a fuse block is bad, but no idea what would be causing it.

Yeowch, that's not good.

 

[bhicks]

Anyone else with any suggestions? I will check the other two grounds when I get off work today but beyond that I have no idea what direction to go in.

 

[bhicks]

It's been 6 years since I started this thread and non of my electrical issues have been solved. My 80 series became our shop truck and occasional weekend wheeler so I just didn't worry about the clock, cig/12 volt plug, antenna, and dome lights all not working. Jump forward 6 years and I got an offer for my daily driver that was WAY more than I paid for it 4 years ago so I sold it. Greed got the best of me. Now my 80 series shop truck is my daily driver once again. As soon as I started driving it I was flooded with the memory of all the electrical issues I never resolved. A new issue has been added. My stereo went out last week. The aftermarket double din is dead. Will not power up. Here is what I need to get this electrical battle started. One, where are the 6 grounds on this 80? I am not finding 6. 2nd, can someone post a pic of the fuse diagram for the under the dash fuse box? My fuse cover is missing and I need to check some fuses first.

 

[SmokingRocks]

Do yourself a favor and download the FSM for your rig at the link in my signature. I'd even go as far as to say you should download the 93-94 FSM that I created (also in my signature) because it's more easily navigatable via bookmarks. Seriously take the time to learn how to read and understand these EWD's because they will SAVE YOU SO MUCH TIME in the future. With these manuals and a simple test light or better yet a multi-meter you can fix just about anything.

For example, open my FSM and expand the bookmarks tab, go to the EWD (Electrical Wiring Diagram), Illumination, scroll to page 76 and there's your dome light circuit.
The Rectangles with XX# labels are connectors which can be seen at the end of the section. The number next to the rectangle corresponds to which pin of the connector the wire is in.

For the radio click on the "Radio" Bookmark and boom there's your radio circuit (bookmarks take you to the first page of the section, the sections end with a troubleshooting page, connector/component locations and the images of the connectors referenced in the section.

Ground Points are the last bookmark, find the circuit you have an issue with and trace it to the labeled ground lets say its your radio ground which in factory form is ground IE.

Now that you know that, go to the Wire Routing | Connector Location bookmark and scroll down till you find the ground tagged IE. This one is located behind the passenger side kick panel against the body.

 

[bhicks]

Do yourself a favor and download the FSM for your rig at the link in my signature. I'd even go as far as to say you should download the 93-94 FSM that I created (also in my signature) because it's more easily navigatable via bookmarks. Seriously take the time to learn how to read and understand these EWD's because they will SAVE YOU SO MUCH TIME in the future. With these manuals and a simple test light or better yet a multi-meter you can fix just about anything.

For example, open my FSM and expand the bookmarks tab, go to the EWD (Electrical Wiring Diagram), Illumination, scroll to page 76 and there's your dome light circuit.
The Rectangles with XX# labels are connectors which can be seen at the end of the section. The number next to the rectangle corresponds to which pin of the connector the wire is in.
View attachment 3125576



For the radio click on the "Radio" Bookmark and boom there's your radio circuit (bookmarks take you to the first page of the section, the sections end with a troubleshooting page, connector/component locations and the images of the connectors referenced in the section.View attachment 3125575


Ground Points are the last bookmark, find the circuit you have an issue with and trace it to the labeled ground lets say its your radio ground which in factory form is ground IE.View attachment 3125574


Now that you know that, go to the Wire Routing | Connector Location bookmark and scroll down till you find the ground tagged IE. This one is located behind the passenger side kick panel against the body.
View attachment 3125573

Wow. That is a LOT of info. This will take me some time to process. I can see in the diagram the two grounds I could not find BUT the location is a bit vague. Are they outside the cab or under the carpet inside the cab?

 

[SmokingRocks]

inside the cabin behind the lower trim piece that runs along the door sill and up into the footwell. There are common ground locations on both sides (drivers side and passenger side) of the cab at these locations. Pop the trim piece up and out and stick your head up there. Toyota uses W-B (White with black stripe), Br-B (Brown with black stripe), and Br (solid brown) wires as grounds for 98% of the rig, you'll see a cluster of them come together at a ring terminal bolted to the body.

Although I doubt it's a bad ground. You should slow your roll and spend some time reading and learning how to read the EWD correctly, then you can apply that to simple test of pins of connectors at various locations to see if you have power to the places you need power to.

If I were to guess blindly I'd put my money on a failed s***ty butt connector behind the radio that some Car Toys "installer" hacked in years ago. I've never come across a bad interior ground on an 80.

 

[bhicks]

I have my homework cut out for me. What I need to get started is the fuse diagram pic that goes on the back of the cover of the fuse block under the left side of the dash. Anyone have a pic of that? At least I think there was a fuse diagram on the back of the cover. I don't have the cover to verify. I want to make sure I don't have a blown fuse before I start getting into wiring diagrams. I'm sure I will have to get into learning and understanding these EWD's since I still have 5 other electrical issues going on. I can handle not having a clock, dome lights, 12 volt charger, antenna, etc. BUT I can't stand not having my radio and not being able to play my music via Bluetooth. I want that fixed first and then the rest will come in time.

 

[ppc]

What I need to get started is the fuse diagram pic that goes on the back of the cover of the fuse block under the left side of the dash. Anyone have a pic of that?

How many times times do you to be told that diagram can be found in the FSM. Look in the first few pages of the "Electrical Wiring Diagrams" Section.

 

[SmokingRocks]

Now take a look at how the radio gets its power and you start to find some commonalities. THe factory radio is powered by both the CIG fuse and the DOME fuse these are the hints on where to look and what to check for, its a clue!!!

We can tell from the power source EWD page that the DOME circuit is ALWAY powered, where the CIG circuit is switched based on the ignition. Therefore the radio's main power would be coming from the CIG circuit while the DOME circuit provides enough juice to keep the radio's preset memory when the cars off. So now you need to test to see how far the power is traveling in those circuits, then you can find the break in the line.

This is how I would do it

• Test the CIG and DOME fuses for continuity if bad, replace the fuses
• Test CIG for 12v power when the ignition is switched on, if no power check FUSE AM1, if no power at AM1 replace FUSIBLE LINK FL AM1
• IF there is power at the CIG fuse then you would need to travel the other direction on the circuit, I'd probably pull the dash and radio out to check to see if the power is making it from the fuse panel to the radio and cig socket.

I put a ton of energy (like, no s*** 16 hours) into compiling, organizing, and bookmarking the FSM to make it easy to navigate for people who are in a pickle just like you to use... Please USE IT!!!!

 

[bhicks]

View attachment 3125847

View attachment 3125846


Now take a look at how the radio gets its power and you start to find some commonalities. THe factory radio is powered by both the CIG fuse and the DOME fuse these are the hints on where to look and what to check for, its a clue!!!
View attachment 3125858



We can tell from the power source EWD page that the DOME circuit is ALWAY powered, where the CIG circuit is switched based on the ignition. Therefore the radio's main power would be coming from the CIG circuit while the DOME circuit provides enough juice to keep the radio's preset memory when the cars off. So now you need to test to see how far the power is traveling in those circuits, then you can find the break in the line.
View attachment 3125860


This is how I would do it

• Test the CIG and DOME fuses for continuity if bad, replace the fuses
• Test CIG for 12v power when the ignition is switched on, if no power check FUSE AM1, if no power at AM1 replace FUSIBLE LINK FL AM1
• IF there is power at the CIG fuse then you would need to travel the other direction on the circuit, I'd probably pull the dash and radio out to check to see if the power is making it from the fuse panel to the radio and cig socket.

I put a ton of energy (like, no s*** 16 hours) into compiling, organizing, and bookmarking the FSM to make it easy to navigate for people who are in a pickle just like you to use... Please USE IT!!!!

Awesome!!! Thank you so much. Your info has been extremely helpful.

 

[gummycarbs]

The first thing I would do is pull the driver's side kick panel, the dashboard face, and the stereo. Then assess any modifications. Alarm and stereo installers love to butcher wiring harnesses and use those godawful Scotchlok connectors that invariably sever the factory wires after a few years of vibration.

Personally, I was lucky enough that the previous owner used a proper stereo wiring adapter. However, I had a bunch of damaged wires behind the kick panel from an alarm install. Also -- and this is probably a complete one-off because how does this even happen -- my dome light was blowing fuses because a metal strip inside the dome light housing was pushed up and shorting against the body. WTF.

 

[SmokingRocks]

The first thing I would do is pull the driver's side kick panel, the dashboard face, and the stereo. Then assess any modifications. Alarm and stereo installers love to butcher wiring harnesses and use those godawful Scotchlok connectors that invariably sever the factory wires after a few years of vibration.

View attachment 3126432

I hate those things, 90% of those "professionals" at car toys and similar auto salons are the lube techs of the accessory install world. Entry level / no propper education on how to do it right and there's no one there to teach them because anyone worth their salt moves to greener pastures.

my dome light was blowing fuses because a metal strip inside the dome light housing was pushed up and shorting against the body. WTF.

Common issue

 

[bhicks]

View attachment 3125847

View attachment 3125846


Now take a look at how the radio gets its power and you start to find some commonalities. THe factory radio is powered by both the CIG fuse and the DOME fuse these are the hints on where to look and what to check for, its a clue!!!
View attachment 3125858



We can tell from the power source EWD page that the DOME circuit is ALWAY powered, where the CIG circuit is switched based on the ignition. Therefore the radio's main power would be coming from the CIG circuit while the DOME circuit provides enough juice to keep the radio's preset memory when the cars off. So now you need to test to see how far the power is traveling in those circuits, then you can find the break in the line.
View attachment 3125860


This is how I would do it

• Test the CIG and DOME fuses for continuity if bad, replace the fuses
• Test CIG for 12v power when the ignition is switched on, if no power check FUSE AM1, if no power at AM1 replace FUSIBLE LINK FL AM1
• IF there is power at the CIG fuse then you would need to travel the other direction on the circuit, I'd probably pull the dash and radio out to check to see if the power is making it from the fuse panel to the radio and cig socket.

I put a ton of energy (like, no s*** 16 hours) into compiling, organizing, and bookmarking the FSM to make it easy to navigate for people who are in a pickle just like you to use... Please USE IT!!!!

Success!! I used your diagrams and comments and went through and located all grounds. I had 4 tight grounds, one finger tight, and one totally loose. Went through all fuses including the ones in question. I had two bad fuses with one being the "cig" fuse. Right now my radio and antenna are working again and my clock is back to working. The 12 volt cig/charger on the dash is still out so I'm guessing it's an issue behind the dash. My dome lights still don't work but the wire from the fuse going to them is getting power. I will go back through your wiring diagrams to better educate myself on the door sensors and dome lights set up to see if I can figure this out. Will also look into the common shorting issue on the roof metal as well. Pulling the dash to check the cig/charger plug will have to happen later. I don't have time for that right now.

 

[BILT4ME]

Success!! I used your diagrams and comments and went through and located all grounds. I had 4 tight grounds, one finger tight, and one totally loose. Went through all fuses including the ones in question. I had two bad fuses with one being the "cig" fuse. Right now my radio and antenna are working again and my clock is back to working. The 12 volt cig/charger on the dash is still out so I'm guessing it's an issue behind the dash. My dome lights still don't work but the wire from the fuse going to them is getting power. I will go back through your wiring diagrams to better educate myself on the door sensors and dome lights set up to see if I can figure this out. Will also look into the common shorting issue on the roof metal as well. Pulling the dash to check the cig/charger plug will have to happen later. I don't have time for that right now.

What year truck are you working on?

You have a number listed in your SIG, but it looks like the only one you still own is a 97.

@SmokingRocks posted wiring diagrams for a 93-94, which are DIFFERENT than a 97.

Also, if your is a LX, there are even more differences.

You need to reference the CORRECT diagram for your truck.