Wire question

[ShinyC10]

So a wire caught fire today and I'm not sure where it leads. It has two wires to a inline fuse and finishes with a two hole strap eyelet that hooks over two bolts. Any ideas what is for? They were red so I'm guessing they are hits and my Dakota digital gauges don't turn on. Need help, gotta get home by tomorrow lol

[gmachinz]

Are u referring to the firewall junction block?

[ShinyC10]

Originally Posted by gmachinz

Are u referring to the firewall junction block?

It's under the hood though

[gmachinz]

Yes it is-above the distributor and towards the drivers side a little?

[ShinyC10]

Originally Posted by gmachinz

Yes it is-above the distributor and towards the drivers side a little?

Bingo! Any specific reason for the strap eyelet or would I be fine twisting them together and putting it under one of the bolts?

[gmachinz]

Its more of a convenience when building harnesses. I stock the dual eyelet terminals for my harness builds. Originally its got one crimp location which originated from the high speed output from the blower relay. You should replace the fusible links @ the junction as well. I use fusible link wire soldered in series.

But, do you know why a wire burned up?

Oh, and yes you can put all the leads under one stud-that won't hurt anything.

[hatzie]

NO The fusible link is before the fuse panel. The fuse will go if the short is after the fuse. If it's between the fuse and the J-Block then the fusible link goes.

Where are you tapping power for the VHX gauges?

Did you move the power tap after this little mishap?

[ShinyC10]

Yes I have a fuse able link between the fuse box and the control box. Power is coming from the an accessory I believe (supposed to be constant)

[ShinyC10]

Originally Posted by ShinyC10

Yes I have a fuse able link between the fuse box and the control box. Power is coming from the an accessory I believe (supposed to be constant)

In addition to my previous reply, no I didn't switch the power source. Still currently in an acc. Going to move it to a constant power source but not sure where

[ShinyC10]

Originally Posted by hatzie

NO The fusible link is before the fuse panel. The fuse will go if the short is after the fuse. If it's between the fuse and the J-Block then the fusible link goes.

Where are you tapping power for the VHX gauges?

Did you move the power tap after this little mishap?

I put another fusible link with those two red wires but it gets real hot when the trucks on.

[hatzie]

You're pulling a lot of juice. Unplug everything extra you've added and turn the ignition on. If it still gets hot you're going to have to chase the short. What fun...

Is it the charge wire or the Ignition Switch wire or both?

[ShinyC10]

Originally Posted by hatzie

You're pulling a lot of juice. Unplug everything extra you've added and turn the ignition on. If it still gets hot you're going to have to chase the short. What fun...

Is it the charge wire or the Ignition Switch wire or both?

I have gauges unplugged and my door locks unplugged and the fusible link itself is getting hot after the truck is on. So tomorrow I'll probably chase down that short. Like you said, "what fun"

[hatzie]

http://realfixesrealfast.com/finding...ive-short.html

Finding an Active Short

[ShinyC10]

Originally Posted by hatzie

http://realfixesrealfast.com/finding...ive-short.html
Finding an Active Short

Thanks for the video, I'll be playing that while I'm under the hood

[hatzie]

Originally Posted by ShinyC10

Thanks for the video, I'll be playing that while I'm under the hood

Figured it might help. No idea what your level of expertise is.

[ShinyC10]

Originally Posted by hatzie

Figured it might help. No idea what your level of expertise is.

I guess we will find out how good I am tomorrow. gonna bring my old man out there to help. Two brains are better than one

[ShinyC10]

Originally Posted by hatzie

Figured it might help. No idea what your level of expertise is.

So got into the wiring today and narrowed it down; with the alternator disconnected that fusible link doesn't get hot BUT when it's plugged in it instantly heats up. Is it possible the alternator is putting out too much juice?

[hatzie]

The Fox N Hound type tools are useful for pinpointing which bundle a wire is in... if you can find an inexpensive one that actually works.
The Extech 40180 is a pretty decent inexpensive unit. It's not a Fluke but it's not priced like one either.

You need the vehicle battery disconnected to safely use it.

[hatzie]

A meter should sit at 14.5V with the engine running. 15+ is too high and 13.x is too low.
Amperage output is by demand up to the capacity of your unit... 10SI=63A, 12SI=78A-94A, CS130=105A. If the battery is low or has a dead or partially shorted cell it'll cause the alternator to push more current and heat stuff up. If you have poor connections to the battery from the alternator you'll get the same results.

[ShinyC10]

Originally Posted by hatzie

A meter should sit at 14.5V with the engine running. 15+ is too high and 13.x is too low.
Amperage output is by demand up to the capacity of your unit... 10SI=63A, 12SI=78A-94A, CS130=105A. If the battery is low or has a dead or partially shorted cell it'll cause the alternator to push more current and heat stuff up. If you have poor connections to the battery from the alternator you'll get the same results.

Tested the alternator and is was fine, replaced the connectors to it and the fusible link. Chased down all the wires and still the fusible link gets hot when the truck is running. I'm at a loss. The red wire that comes off the fusible link and plugs into the alternator gets hot but the other red wire in the fusible does not. Also, turned the truck on for maybe 20 seconds and the alternator is burnin up.

[hatzie]

Be sure the ground cable to the alternator bracket is making good contact and the bracket is making good contact with the alternator itself as well.

Star washers are your friend.
The easy way to test this is reading volts from the BAT terminal to the alternator case and comparing to the volts across the battery terminals. They should be the same. If they aren't you have a bad contact at the J-Block or the starter or the ground ^^^ is not making good contact. You can do a voltage drop test across all of these connections.

Easy Voltage drop tests to check your cables...http://aimpartsonline.com/reduce%20warranties

Is the 14ga red sense wire on the plug intact from the alternator through its' fusible link to the starter? Can you read more than @.1 DC volts from the BAT terminal to the sense wire? This means there's a voltage drop across these wires. There shouldn't be. The J block is fed from the starter through a fusible link. The sense wire is attached at the same place on the starter through a different fusible link.

Internal failure. Bad regulator, bad diode, improper alt fan, bad bearing, defective heat sink??

[ShinyC10]

Originally Posted by hatzie

Be sure the ground cable to the alternator bracket is making good contact and the bracket is making good contact with the alternator itself is as well.

Star washers are your friend.

Also, we noticed that the dome light won't go out when the truck is off and doors are shut. It just dims down when I shut the door

[ShinyC10]

Originally Posted by hatzie

Be sure the ground cable to the alternator bracket is making good contact and the bracket is making good contact with the alternator itself is as well.

Star washers are your friend.

ill check that

[ShinyC10]

Originally Posted by hatzie

Be sure the ground cable to the alternator bracket is making good contact and the bracket is making good contact with the alternator itself as well.

Star washers are your friend.
The easy way to test this is reading volts from the BAT terminal to the alternator case and comparing to the volts across the battery terminals. They should be the same. If they aren't you have a bad contact at the J-Block or the starter or the ground ^^^ is not making good contact. You can do a voltage drop test across all of these connections.

Easy Voltage drop tests to check your cables...http://aimpartsonline.com/reduce%20warranties

Is the 14ga red sense wire on the plug intact from the alternator through its' fusible link to the starter? Can you read more than @.1 DC volts from the BAT terminal to the sense wire? This means there's a voltage drop across these wires. There shouldn't be. The J block is fed from the starter through a fusible link. The sense wire is attached at the same place on the starter through a different fusible link.

Internal failure. Bad regulator, bad diode, improper alt fan, bad bearing, defective heat sink??

So I got the grounds improved and the alternator still seems to be heating up. It is putting out 14.4/14.5v but continues to heat up in the matter of a couple minutes. The wire off the alternator that runs to the fusible link is getting hot as well but the second wire within the fusible link doesn't.

[hatzie]

The jamb switch has failed or the switched wire has rubbed through and is grounding out. The dome/courtesy lamps use a switched ground on the doorjamb and the headlamp switch.

The voltage drop tests across the cables are bloody easy and quick to do. They don't require $1000 in tools to execute either.