15a fuse blowing... also won’t start.

[anormalflame]

Is your fuse panel like the one in the schematic you post?
If so your not pulling 1a. The drawing showing the connectors on the back is rolled over to the right. In the upper left corner of the back would be the power relay.

You need to detail exactly what you did to the vehicle after you pulled it into the garage. Step by step in detail.
Your posts are so all over the place it took folks 2 pages to realize you drove the rig after you suspect your brother damaged it. And it seems you have 2 threads going for the same issue.


This is what I gathered:
#1: You had to jump your rig to get it to start one day.
#2: You loaned your rig to your brother and he had to jump it as well.
#3: You got your rig back and lots of fuses were blown including the 100A ALT fusible link.
#4: You replaced the ALT link and other fuses and drove your rig for a few days.
#5: At some point presumably after #3 the 15A (dome?) fuse would blow instantly.
#6: You parked you rig in the garage and started pulling stuff apart.
#7: After step #6 the vehicle will not start.
#8: You have determined that pulling the upper left connector from the back of the fuse panel driver side dash stops the 15A (dome) fuse from blowing.

Questions:
At step 2 did your brother ever get the rig running?
At step 3 what exact fuses were blown and in what fuse boxes?
Can we assume these are the same fuses replaced in step 4?
Step 5 seems cut and dry, but you’ve stated “15 amp fuses”, plural. How many and what fuses currently blow provided the mystery connector is connected?
In step 6, please detail exactly what you did step by step.

We can help you, but you need to be clear and detailed. Try not to include speculation and assumption. Just tell us exactly what you know and exactly what the symptoms are. Don’t leave any details out. Something you regard as unimportant could be very important.

Got the correct manual now from a fellow member. It wasn't 1A. It's 1J.

1. Truck wouldn't start. Jumped it off.
2. Loaned to brother. Returned with dome fuse blown, door locks not working, and turn signals not working. Tried to swap 15a dome fuse out, but it blew. I had to go somewhere for a photography job so I drove it anyway. Drove fine.
3. Came home to try to figure this out. Drove it in the garage. I swapped fuses - the 10a AC, 10a RR HTR, 10a Head (RH), 10a Head (LH), all under the hood and the ACC (inside truck) after using a test light. Now only the 10a AC fuse lights up using a test light out of that cluster of 10a fuses in that middle section of fuses under the hood. They aren't blown, the test light just doesn't illuminate on either side. Tried swapping dome fuses but they kept blowing again.
4. I began pulling the connectors behind the fuse box inside the truck. Narrowed it down to one connector which I now know is the 1J. I used my test light poking inside each slot for the wires on that connector. On one of them on the left side I heard the relay click under the hood as the test light lit up. There was one on the right side that made the test light illuminate, but it was very dim. Not sure what that means.
5. Truck would crank but not start.
6. I swapped the 100 ALT fusible link because it appeared to be blown, but I couldn't really tell for sure due to lack of visibility through the plastic. Also because other T4R.org members had theirs blown while diagnosing similar issues. Just figured what the hell. I'll swap it.
7. Here we are.

Brother got the rig running fine... So did I. It only stopped running after pulling into the garage to diagnose.

I only had to swap the other fuses once. Sorry I meant fuse not fuses.

Thanks for your help.

 

[Dieselchessy]

Did you try starting the rig between steps 3 and 4?

I’m not sure what to make of your comment about the 10amp fuses no longer having power. I take that to mean they did have power at some point?

Do you only own a test light, or do you have a volt meter?

I’m assuming you’ve tried plugging connector 1j in and the rig still won’t start.
That should indicate that in the work that took place in steps 3 and 4 is most likely the event that caused the vehicle to not start.

It seems suspect that in step 3 something happened to cause power not to be properly distributed in the under hood relay box.

I don’t have the 97 schematics. You should investigate the power distribution in the under hood fuse panel. I suspect you’ve blown one of the larger (30 amp) fuses or fusible links other than ALT. ALT shouldn’t do much other than carry current to/from the alternator.

Be careful poking around with a test light. You might accidentally short something.

 

[Dieselchessy]

Got the correct manual now from a fellow member. It wasn't 1A. It's 1J.

1. Truck wouldn't start. Jumped it off.
2. Loaned to brother. Returned with dome fuse blown, door locks not working, and turn signals not working. Tried to swap 15a dome fuse out, but it blew. I had to go somewhere for a photography job so I drove it anyway. Drove fine.
3. Came home to try to figure this out. Drove it in the garage. I swapped fuses - the 10a AC, 10a RR HTR, 10a Head (RH), 10a Head (LH), all under the hood and the ACC (inside truck) after using a test light. Now only the 10a AC fuse lights up using a test light out of that cluster of 10a fuses in that middle section of fuses under the hood. They aren't blown, the test light just doesn't illuminate on either side. Tried swapping dome fuses but they kept blowing again.
4. I began pulling the connectors behind the fuse box inside the truck. Narrowed it down to one connector which I now know is the 1J. I used my test light poking inside each slot for the wires on that connector. On one of them on the left side I heard the relay click under the hood as the test light lit up. There was one on the right side that made the test light illuminate, but it was very dim. Not sure what that means.
5. Truck would crank but not start.
6. I swapped the 100 ALT fusible link because it appeared to be blown, but I couldn't really tell for sure due to lack of visibility through the plastic. Also because other T4R.org members had theirs blown while diagnosing similar issues. Just figured what the hell. I'll swap it.
7. Here we are.

Brother got the rig running fine... So did I. It only stopped running after pulling into the garage to diagnose.

I only had to swap the other fuses once. Sorry I meant fuse not fuses.

Thanks for your help.

Not sure why your 10A RR HTR fuse wouldn't have power unless somethings not connected under the relay box, or bad connection.

 

[Dieselchessy]

Look at the EFI fuse under the hood and all the fuses under the dash, 7.5A ignition, ECU, ect….

Under the dash relay box looks to have the important stuff on 1H.

Given the starter turns over the AM1 and 2 fuses should be good.

 

[phattyduck]

Got the correct manual now from a fellow member. It wasn't 1A. It's 1J.

1. Truck wouldn't start. Jumped it off.
2. Loaned to brother. Returned with dome fuse blown, door locks not working, and turn signals not working. Tried to swap 15a dome fuse out, but it blew. I had to go somewhere for a photography job so I drove it anyway. Drove fine.
3. Came home to try to figure this out. Drove it in the garage. I swapped fuses - the 10a AC, 10a RR HTR, 10a Head (RH), 10a Head (LH), all under the hood and the ACC (inside truck) after using a test light. Now only the 10a AC fuse lights up using a test light out of that cluster of 10a fuses in that middle section of fuses under the hood. They aren't blown, the test light just doesn't illuminate on either side. Tried swapping dome fuses but they kept blowing again.
4. I began pulling the connectors behind the fuse box inside the truck. Narrowed it down to one connector which I now know is the 1J. I used my test light poking inside each slot for the wires on that connector. On one of them on the left side I heard the relay click under the hood as the test light lit up. There was one on the right side that made the test light illuminate, but it was very dim. Not sure what that means.
5. Truck would crank but not start.
6. I swapped the 100 ALT fusible link because it appeared to be blown, but I couldn't really tell for sure due to lack of visibility through the plastic. Also because other T4R.org members had theirs blown while diagnosing similar issues. Just figured what the hell. I'll swap it.
7. Here we are.

Brother got the rig running fine... So did I. It only stopped running after pulling into the garage to diagnose.

I only had to swap the other fuses once. Sorry I meant fuse not fuses.

Thanks for your help.

3. Headlight fuses won't have power unless the headlight switch is on. 50A Heater and 10A AC fuses won't have power unless the 10A gauge fuse is outputting power (key ON). 10A RR HTR fuse should have power all the time (though the rear heater itself will only work with vehicle "ON" via GAUGE fuse power and rear heater relay).

1J connector has:

1 - R-L, 10A GAUGE fuse power output (to alternator and other stuff)
2 - R, Headlight relay trigger signal (pulls to ground when switch is ON)
3 - L-W, Power in from HORN relay
4 - B, Power to horns from HORN relay
5 - empty
6 - G, Power from TAIL relay for integration relay and interior light power
7 - R-G, LH headlight low beam ground connection to headlight switch
8 - B-W, 7.5A IGN fuse power output
9 - R-G, RH headlight low beam ground connection to headlight switch
10- G-Y, Front RH turn signal power out
11- G-B, Front LH turn signal power out
12- L-Y, Power input from 15A DOME fuse to integration relay and other systems
13- empty

I'd try removing the integration relay and plugging 1J back in to see what happens. The next thing is to go down the line with every component that is connected to the DOME fuse...

-Charlie

 

[Dieselchessy]

Charlie,

I’m probably just getting in the way on this one.

My thought, given the vehicle used to run with the 15A dome fuse blown, would be to disregard the dome fuse and concentrate on getting the vehicle back to running. Then revisit the Dome fuse issue.

Do you think it’s better to try and resolve the Dome fuse issue first? Or that the Dome fuse issue is key to the vehicle running?

 

[phattyduck]

Charlie,

I’m probably just getting in the way on this one.

My thought, given the vehicle used to run with the 15A dome fuse blown, would be to disregard the dome fuse and concentrate on getting the vehicle back to running. Then revisit the Dome fuse issue.

Do you think it’s better to try and resolve the Dome fuse issue first? Or that the Dome fuse issue is key to the vehicle running?

I think something was left unplugged during the debug process and that the non-running condition is a red herring at this point.

-Charlie

 

[brillo_76]

Wow you guys have been busy. What stinks is it's so easy to accidentally leave a connection unplugged and then things just go south.



Sent from my SM-J337V using Tapatalk

 

[anormalflame]

Did you try starting the rig between steps 3 and 4?

I’m not sure what to make of your comment about the 10amp fuses no longer having power. I take that to mean they did have power at some point?

Do you only own a test light, or do you have a volt meter?

I’m assuming you’ve tried plugging connector 1j in and the rig still won’t start.
That should indicate that in the work that took place in steps 3 and 4 is most likely the event that caused the vehicle to not start.

It seems suspect that in step 3 something happened to cause power not to be properly distributed in the under hood relay box.

I don’t have the 97 schematics. You should investigate the power distribution in the under hood fuse panel. I suspect you’ve blown one of the larger (30 amp) fuses or fusible links other than ALT. ALT shouldn’t do much other than carry current to/from the alternator.

Be careful poking around with a test light. You might accidentally short something.

Unfortunately I didn't try starting it between steps 3 and 4 because I had no reason to believe it wouldn't start. That wasn't the problem at that point.

From what I gather, those fuses only have power when it's on.

Yep tried reconnecting and that didn't help.

 

[anormalflame]

Look at the EFI fuse under the hood and all the fuses under the dash, 7.5A ignition, ECU, ect….

Under the dash relay box looks to have the important stuff on 1H.

Given the starter turns over the AM1 and 2 fuses should be good.

I swapped AM 1 & 2. They're good.

How do I test the AFI fuse? It's a big black cube on my 97.

 

[Dieselchessy]

Black cubes with 4+ legs in a T pattern should be relays, not fuses.

You should have an EFI fuse, per the schematics, in the under hood relay box.

I believe someone sent you the electrical schematics. In those they have sections that describe the components, as well as what does and doesn’t have power when ignition is on, acc, ect....

 

[anormalflame]

3. Headlight fuses won't have power unless the headlight switch is on. 50A Heater and 10A AC fuses won't have power unless the 10A gauge fuse is outputting power (key ON). 10A RR HTR fuse should have power all the time (though the rear heater itself will only work with vehicle "ON" via GAUGE fuse power and rear heater relay).

1J connector has:

1 - R-L, 10A GAUGE fuse power output (to alternator and other stuff)
2 - R, Headlight relay trigger signal (pulls to ground when switch is ON)
3 - L-W, Power in from HORN relay
4 - B, Power to horns from HORN relay
5 - empty
6 - G, Power from TAIL relay for integration relay and interior light power
7 - R-G, LH headlight low beam ground connection to headlight switch
8 - B-W, 7.5A IGN fuse power output
9 - R-G, RH headlight low beam ground connection to headlight switch
10- G-Y, Front RH turn signal power out
11- G-B, Front LH turn signal power out
12- L-Y, Power input from 15A DOME fuse to integration relay and other systems
13- empty

I'd try removing the integration relay and plugging 1J back in to see what happens. The next thing is to go down the line with every component that is connected to the DOME fuse...

-Charlie

I pulled each connector in the integration relay after plugging the 1J back in. The 15a Dome fuses continued to blow after I pulled both one at a time.

My stereo is unplugged. The dome light has been unplugged as well.

 

[anormalflame]

Black cubes with 4+ legs in a T pattern should be relays, not fuses.

You should have an EFI fuse, per the schematics, in the under hood relay box.

I believe someone sent you the electrical schematics. In those they have sections that describe the components, as well as what does and doesn’t have power when ignition is on, acc, ect....

AHA! Not sure when, why, or how, but that fuse had blown. Replaced it just now. AND IT STARTED!!! Woohoo...

Now to figure out this 15a Dome fuse blowing situation.

 

[anormalflame]

I think something was left unplugged during the debug process and that the non-running condition is a red herring at this point.

-Charlie

I don't know when, why, or how, but the EFI fuse had blown. Per Dieselchessy's instructions, I checked it again and it was blown. I swapped it, and it started!

So that's out of the way...

 

[anormalflame]

Sorry guys. I know that was a dumb thing to overlook these past few days. But it's starting up now. I can't thank you enough for your help. This has been both interesting and educational.

Now I'm trying to find the cause for the continuous 15a Dome fuse blowing.

 

[Dieselchessy]

Ok. Good news, the truck running should eliminate lots of stuff and ECU damage.

 

[anormalflame]

Ok. Good news, the truck running should eliminate lots of stuff and ECU damage.

Thanks again man!

Now I'm trying to unplug everything on that circuit. And trying to figure out what all that entails so I can plug each back in to see what might be the cause. I'm working with the door closed so the switch in the door isn't overlooked.

 

[anormalflame]

Okay so I've been studying the diagrams a bit. I've plugged back in the 1J connection.

I unplugged the 1F connection which controls the stereo, antenna, door switches. The new Dome fuse didn't blow. Now my personal lights work and my dome light will work in the Door position, but not the ON position.

 

[Dieselchessy]

Maybe investigate the wires in the rubber flex boot for the drivers door. Maybe shorted in there.

You had said the radio was unplugged. Are you sure nothings shorted in the radio wires or maybe the power antenna.

 

[anormalflame]

I've pulled the connection from the antenna. No change. Dome fuse blows.

Stereo is still pulled.

I pulled driver side door switch in question. No change. Still blows dome fuses.

To recap: When I pull the 1F connection behind the fuse panel, I don't blow any fuses. And actually, my map lights and dome light will work with a fuse reinstalled. The dome light only works when in the Door position. However, I've noticed that the rear cargo light will not work at all.

I've attached the overall electrical wiring diagram. Searching for dome within the file and trying to see what to do next.
View attachment Overall_EWD.pdf