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View Full Version : wiring an 82 258 into a 74 wiring harness?


AMX
01-03-2004, 07:50 AM
I have a 74 J10 with a 258 that is dated from 82 and has the ignition module whereas the 74 used a points distributor. The resistance wire I spliced into gets pretty warm while the engine is running. I am wondering if anyone else has seen this and knows how to fix this.
Thanks

tgreese
01-03-2004, 08:11 AM
A resistance drops voltage by disipating the power as heat - the wire is going to be warmer than the surroundings. I'd worry if it were too hot to touch.

Somebody out there will know about the Motorcraft/Duraspark and will be able to tell you if the stock Duraspark ignition needs a voltage drop. From this drawing http://www.trailhed.com/images/DuraSpar.jpg it looks like the coil operates at a reduced voltage, but someone should confirm this.

[ January 03, 2004, 03:15 PM: Message edited by: tgreese ]

oldjeepr
01-03-2004, 12:49 PM
that is the reason they are a certain length so much wire equals so much drop, i would consider where it was spliced and you are not running a too short wire or too long compared to what lenght it should be

oldjeepr
01-03-2004, 12:51 PM
and looking at your scematic it shows a resistance wire to the coil