long story short I drilled through the firewall on the passenger side and hit the wiring harness that goes to the distribution block by the battery. It sparked, and blew the fusible link. I repaired the wire and the fusible link. The car starts up and runs fine but that wire by the fusible link gets hot and blows the fuse. It is the red wire that goes up to the ignition switch. I thought maybe I fried the ignition switch so I replaced it and no change. Spent all day chasing wires and everything looks to be fine. I even replaced the fusible link with a factory one off of another car and still the same thing. I missed work today and I need to go to work tomorrow so any help tonight would be appreciated. The car is an 86 SE v6 4 speed.
I went and baught one of the ones off the shelf. The problem with that is, the o.e. is 2 different guage wires. The new one with the glass fuse is the same guage on both ends. The side that bolts to the terminal by the distribution block is where it keeps getting hot and blows the fuse.
If you installed a glass fuse, that's no good. A fuse and a fusible link are two different things. A fuse can't stand up to a surge in current and a fusible link can. Parts store sell fusible links or fusible link wires
Ok so, the red wire from the ignition switch is still getting hot. I put the key in the run position, turned on lights, fan, and blower for the vents. The fusible link coming out of the Junction block is the only part getting hot. I don't see any ground wires at all. I'm at a loss. This is my daily driver! Any ideas are welcomed!!!
Your link getting hot has to do with the circuit that it is powering...not the Junction block. Have you looked at the resistor plate? Do you have any battery drain? Does the link get hot with key on, everything off? Turn on one thing at a time to see when the link gets hot.
[This message has been edited by Gall757 (edited 03-02-2016).]
I've narrowed it down to the blower motor for the ac, and the radiator fan motor. I'm tracing the wires back but so far, everything looks good. From what I've read, this circuit powers the headlights, rad fan, and ac blower, and maybe the rally guages. The headlights aren't causing it to get hot. The blower and rad fan are. I've torn out everything including my skeleton, steering colomn, and looked at every ground I could think of. And it all checks out.
I can run the car with nothing on and it's all fine. I've unplugged and looked at the relays for the blower, and the rad fan. Not one single wire is even discolored. The only wire that was hit was the red wire going to the ignition switch. As far as I can see from the diagrams, it goes straight from the Junction block to the switch. One wire, no stops along the way.
I've narrowed it down to the blower motor for the ac, and the radiator fan motor. I'm tracing the wires back but so far, everything looks good. From what I've read, this circuit powers the headlights, rad fan, and ac blower, and maybe the rally guages. The headlights aren't causing it to get hot. The blower and rad fan are. I've torn out everything including my skeleton, steering colomn, and looked at every ground I could think of. And it all checks out.
Does the blower blow the fuse even if the AC is off? Maybe its just the rad fan, since the rad fan always kicks on if the AC button is pushed.
If so you could alt least unplug the rad fan and drive it, unless your car runs hot (well maybe you cant, you are in Texas.).
[This message has been edited by 2.5 (edited 03-03-2016).]
I think the next step would be measuring ohms of resistance on individual components / wires. I'm no expert at that. Id start with the rad fan. Could also measure if the battery is draining when the car is off?
It still gets hot. I shut it off before it gets a chance to blow the link. I replaced alternator thinking maybe I fried the diodes. No change. Found the rad fan motor relay would cut off if I wiggled it. Put a new one on there. Works perfectly. But fusible link "a" and "e" are still getting hot. Link "e" is only slightly warm as where link "a" is getting uncomfortably hot. I've tried all combinations of lights, rad fan, and ac. Fan only; link a is warm. Ac only; link a is hot Lights only; link a is nice and cool. Car running with ac on; link a is hot hot and link e is warm. Checked blower relays and resistor, all are fine. Followed grounds, all look good. There is another thread started severe months back describing the exact same thing but with no resolution. https://www.fiero.nl/forum/Forum2/HTML/135599.html
Edit: how do you know if the Junction block is bad or has a bad connection? I took it all off and it looks ok. Oohing is broken and the dual eyelet is clean as well.
[This message has been edited by NEVERDONE (edited 03-06-2016).]
If you had a "clamp on" amp meter you could measure the current draw at the fuse link and each component. A "clamp on" amp meter allows you to measure the current without damaging the wiring by clamping around the wire. It's a very useful tool.
Measure the current at the link and the component, then the link and the other component. See how turning on and off the component affect the current draw. With that information you could possibly determine the bad component. I would guess that the radiator fan would draw about 15 amps and blower motor would draw 10 amps. If the current does not change the same at both location it would indicate a short or ground between the link and component.
------------------ 88 GT 5 Speed Black with gray interior 3800 SCII Swap Complete. Paint Complete Detailing in Progress
IT RUNS!! IT'S QUICK!!
"Real integrity is doing the right thing, knowing that nobody's going to know whether you did it or not."
Shop narrowed it down to the blower motor. Said it was pulling a constant 17 volts or amps, don't remember. Got new blower motor. Installed and same results. Fusible link getting hot . I baught new fusible link wire, installed, STILL effin getting hot!
That sucks about the blower not fixing it. 17 amps would be a lot, my blower motor tested at 9.8 amps. I am waiting to buy an amp clamp as the ogre suggested to further diag mine. What can you tell me about your cars history and what if anything you've done to it? I'm starting to think ouside the box on mine....seeing that Fuse A powers a lot of things inside the car as well.
I would start by disconnecting the blower motor and running it directly to the battery while checking it's current draw...just to see what it should be drawing. With it disconnected at the blower and the battery disconnected, check the resistance of the blower wires (heading to the relay) to ground. If you have almost no resistance then you've missed a short somewhere.
Well after all that I could think of, I finally just put a 40 amp maxi fuse in place of the fusible link. I ran the heater and the ac all the way home yesterday and today. It was just slightly warm to the touch. I'll keep driving that way until it blows the fuse or whatever component is not doing what it's supposed to be doing! And carrying an extra fuse as well!
