Ignition Wiring Harness Gets Hot??? (Yellow Wires) - MustangForums.com

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Old 08-02-2010, 07:27 PM   #1
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Default Ignition Wiring Harness Gets Hot??? (Yellow Wires)


I have a 1988 Mustang GT 5.0L, It's been converted from Speed density to MAF and has a MSD 6AL Box and upgraded to a 130amp alternator from a newer GEN.

Before the upgrades I had this problem and continue to have this problem after the upgrades. The ignition switch has been getting HOT and falls apart. I have replaced the ignition switch twice and continue with the same problem. This time around I have replaced the ignition switch and the starter solenoid that is mounted on the fender and I continue to have the same problem. I have noticed that the two yellow wires that are on ignition switch harness are the ones that are getting hot and the plug has started to melt. Does anyone have any sugestions as to what should be my next step?

Thanks Again
1988 Ford Mustang GT, bored 30 over 10/10 grind on crank, Maf Conversition, 24lb inj., MSD 6AL. Edelbrock RPM Performer Upper and Lower.

Last edited by 88GTBLKBTY; 08-02-2010 at 08:11 PM.
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Old 08-03-2010, 01:35 PM   #2
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The 2 yellow wires on your ignition switch are 12v constant power... Have you measured voltage there to see if you getting the right voltage? I am not sure of the amperage though...I am wondering if you getting a spike or arc from somewhere causing the melting problem.
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Old 08-03-2010, 02:58 PM   #3
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^^^voltage doesn't cause heating of wires, it is current draw/amperage or excessive current draw and or high resistance in wiring/connections that causes such............anyway, you need to make sure the connection there is good and tight and those 2 wires that get hot that the crimp connection is tight, often it is a problem in the connector/ across the pin connection, if the connector and or pins in the connector show any signs of melting, overheating and or blueing of the metal pins, = replace the connector and check the ground connection for the ignition switch, can't remmeber if it has such but looking at a diagram, you should be able to determine such if it has such , trace it and see where the ground leads to, faulty grounds will cause high resistance and up the current draw, thus overheating a circuit
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Old 08-04-2010, 05:23 PM   #4
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Thanks Guys!!! I'll check the items that you guys have mentioned and I'll update after checking!!!
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1989, 23l, 6al, 88, ford, gt, harness, hot, ignition, melted, msd, mustang, starter, switch, wire, wires, wiring

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