Fuse Block-Partial Loss of Power?

[KK5 Native]

I have a 1980 K5. The owner prior to me installed a remote windshield washer fluid pump with a dedicated toggle switch and the pump went out. I installed a new one and it didn't work. While I was messing around with it doing a voltage check the positive wire popped off and shorted out to the wheel well. Not a big deal in a normal fusible set up but this guy connected the positive wire directly into the fuse block with a stab in male connector (where you would put a fuse) in the lower portion of the fuse block. Now part of the lower portion of the fuse block does not have any power.

Does anyone know if the fuse block has a hidden fusible link connecting the top to the bottom? It's tucked up under the dash so nothing was visible from what I could see.

Any thoughts, ideas, experience or suggestions?

 

[dyeager535]

Only things I'm aware of on the fuse panel that are easily replaced (and I'm not that familiar with the earlier panels like yours) are the shunts and the circuit breakers.

The shunts, if present, look kind of like blade fuses, black, mine are labeled "SHUNT" in white letters. The circuit breakers are little metal boxes that plug in similar to fuses. Mine has two. Outside of that, probably have to disassemble the panel to see what burnt.

 

[dhcomp]

Double check the fuseable links that come off the starter positive lug.

I think there is more than one. Not sure how it ties back into the fuse block, but worth a shot.

 

[Rugger187]

There is a fusible link on the junction block near the brake booster. Mine fried and killed the truck. Took forever to find it. The link melted but didn't melt the wire housing.

 

[dyeager535]

OP said the PO (ha!) connected the fuse block directly from the battery, so the fusible links wouldn't play a part if that's the case.

 

[dhcomp]

OP said the PO (ha!) connected the fuse block directly from the battery, so the fusible links wouldn't play a part if that's the case.

If this is the case, change is ASAP to factory style fuseable links. They are there for a good reason.

 

[Rugger187]

I wouldn't do factory style fusible links. I would do blade style fusible links.

 

[dhcomp]

I wouldn't do factory style fusible links. I would do blade style fusible links.

Do they make blade style fuseable links, or do you just mean fuses?

The benefit to the fuseable links is that they take some time to melt/burn. A blade style fuse will blow instantly.

The factory stuff was protected by instant fuses at the box, and fuseable links as a last resort backup.

You could go to a resettable breaker for the fuseable links, so at least you could reset it....but it will still trip instantly.

For ever person who has issues with the factory fuseable links, 10000 more people have no issues. Especially around here, guys know to check them. I feel they are the best way to handle the need for a last ditch electrical protection.

 

[Rugger187]

I used some blade style fusible links. I had a wire ground out and melt my OEM fusible link.
I fixed the grounding out issues and run a 30amp fuse. Keep a few for backup but haven't had a problem since.
Well, no problems in THAT area. Don't ask about the rest....

 

[Blue85]

Under the right conditions, everything is a fusible link. Like stated already, check all the links coming off the starter and the one on the firewall. Find a wiring diagram and it should reveal which wire powers the dead portion of your fuse block. If all the links are good, there is a damaged wire or bus bar in the block itself. You want to repair it instead of just jumping power over from another part of the block. That would just give more load on that wire/link and cause something else to fail later (or at least annoy you with more voltage drop on everything).

 

[KK5 Native]

Under the right conditions, everything is a fusible link. Like stated already, check all the links coming off the starter and the one on the firewall. Find a wiring diagram and it should reveal which wire powers the dead portion of your fuse block. If all the links are good, there is a damaged wire or bus bar in the block itself. You want to repair it instead of just jumping power over from another part of the block. That would just give more load on that wire/link and cause something else to fail later (or at least annoy you with more voltage drop on everything).

Thanks. That is very good information. I noticed on the wiring diagram that there was (2) fusible links but I couldn't locate the second one.

I think one of them is partially fried because the low amperage draw things function but something with a high amperage draw (heater blower motor) does not function.

I was getting ready to pull the fuse block out but this gives me one more spot to check before I do that. I definitely would not hack in a jumper to mask or add to the problem. That's what the previous owner before me did and is why I'm in this rat nest predicament. Frustrating that people consider that as an option, right?

After simply taking voltage readings throughout the system while operating, I discovered that the voltage regulator was bad on the alternator. It was cooking my batteries putting out 15.7 volts. That was an easy swap but nice to catch it.

 

[dhcomp]

There are 2 at the main battery stud at the fuseblock.

 

[diesel4me]

The square body trucks I've had ,had 2 fusible links at the starter solenoid,the two thick red wires with a ring connector that bolt behind the positive battery cable at the solenoid have those 2,and they are hidden in a metal conduit pipe that bolts to the tranny bellhousing bolt..

There is another one (or more) at the junction block near the brake booster,and I believe the junction block has a metal fuse link joining the two studs also,not sure if that is fusible or heavy enough not to melt..

Remember ,if the altenator #2 terminal sees no voltage or low voltage,that is the "sensing" part of the regulator and it'll "tell" the altenator to jack up the voltage and amps,it will think the battery is low on charge...so the regulator might not be faulty..