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Topic: How to tell if a fusible link is toast (Read 2101 times) previous topic - next topic

How to tell if a fusible link is toast

I had another stupid (on my part) short just off the ign switch and I got a beautiful pssssssff from my inner fener area and a bunch of smoke!  Finally got to the bundle of fusible links and none are missing the insulation...?  How can I tell if they are shot?  One is soft and the insulation if loose, but none burned through.
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

How to tell if a fusible link is toast

Reply #1 –
Well, if it helps anyone else, I gave each a very slight tug and the only one that had a touch of stretch had to be it.  So I pulled harder and it stretched and snapped...
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

How to tell if a fusible link is toast

Reply #2 –
I used a volt meter with the continuity test thingy... I cant remember what its called off the top of my head...
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

How to tell if a fusible link is toast

Reply #3 –
That would be the ohm tester part of the meter.

How to tell if a fusible link is toast

Reply #4 –
prob the wiring harness after each splice with stick pins.

turn on the car and read the voltage at the stick pin closest to the source of power with the meter.

now read the voltage on the other stick pin. 

with a digital meter, there should be a voltage difference,, how much depends on the ohm rating of the shunt (fuse link).

If i were to see anything greater than a half volt, that means problems.

The wires are suppose to be direct shorts with potential to fry open and save your wiring harness from burning up.  they are typically one or two wire sizes smaller than the harness they are in line with.  The splices can get corroded and add to the resistance and thus increasing the voltage drop across them.

so there you have it.

easy nuff.

How to tell if a fusible link is toast

Reply #5 –
Quote from: booksix;225120
Well, if it helps anyone else, I gave each a very slight tug and the only one that had a touch of stretch had to be it.  So I pulled harder and it stretched and snapped...

This is the easiest way to test them... If it comes apart with a little tug, was going to fail anyway....

How to tell if a fusible link is toast

Reply #6 –
yeah, I was just hoping there'd be a visual cue.  I didn't want to have to probe them all.  But it worked out good finding the one that was ONLY rubber by pulling...
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

How to tell if a fusible link is toast

Reply #7 –
FWIW they are designed to fry so your car doesn't burn up.  I had one burn up and stay intact until I touched it and it fell apart like a long cigarette ash right befor it gets flicked off.
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

How to tell if a fusible link is toast

Reply #8 –
Right... I am just really surprised that it could completely burn up AND put out that much smoke yet leave the rubber insulation intact and virtually perfect to the eye.
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

How to tell if a fusible link is toast

Reply #9 –
Probably designed that way (theoretically). If the insulation was completely gone, the exposed end that's still connected to the battery could flop around and short out yet again.
Death awaits you all with nasty, big, pointy teeth.

1988 5.0 Bird, mostly stock, partly not, now gone to T-Bird heaven.
1990 Volvo 740GL. 114 tire-shredding horsies, baby!