My friend recently purchased a 1986 Ford F150 4x4 style side and I'm helping him get it running and driving again.
This is a 351W, automatic truck and the engine has received some modifications that are unknown to us at this time....but I see Edelbrock intake and alum heads and headers.
We are told this 351W was removed from a 1969 Mustang, but we have yet to verify that.
This engine is also wired to (what appears at this time) both an MSD 6AL box and the factory Duraspark box.
I'm guessing they built in a "safety" where if the MSD failed, they could hook up the Durspark, but that is just a guess on my part.
I say this because all the wires, from both boxes, still run in the harness (covered by tape and such) and the MDS distributor has been converted to have a factory Duraspark 4 prong connector, otherwise why not remove the unused unit.....and yeah, they used the dang blasted blue scotchlok crimp connectors...so that will have to be fixed.
The truck was last registered in 2011 and has been sitting (according to seller) in the garage unused since that time.
Apparently, they had some issues with getting it running so the story goes.
I intend to pull the distributor and prime the engine prior to cranking things over and starting the engine.
Yesterday we installed a new battery and were fiddling with the various electric components...and things work!
Elec windows go up and down, auto locks open and close, wipers, lights...and so on.
When we got to trying the heater blower motor though I noticed a very high-pitched whine/tone coming from the MDS box that was directly related to the blower motor, including a change in sound with a change in blower motor speed.
With the blower motor off, but truck powered up, there is no extra sound from the MSD box.
But turn on the blower fan and the MSD box sounds like a geiger counter.
I'm currently guessing a few things.
1) The wiring is jacked on this truck and they connected some things together that should not be.
2) The blower motor is failing and arcing when running, causing a lot of RF feedback in the wiring harness.
3) They have both the MSD and Duraspark systems joined in some manner, and powered by the same 12V lead as the blower motor/resistor/controls causing feedback.
We noticed this last evening and were just about done for the night anyway, so I just stopped and decided to figure this out next.
At this time we have not seen, or had, the engine running as it was purchased in a non-running state.
Any helpful hints might lessen my investigation and diagnostics time...and would be greatly appreciated.
I'm just hoping I don't open the wire harness coverings to find a mess of ruined things by enthusiastic electricians with knives, crimp connectors, and black tape.
