We swapped out a 4.9L with a spun bearing for a used 4.9L. Everything seemed smooth, but we can't get it to crank. Solenoid click, then nothing. Tried jumping it, when we tried to start it, sparks on the positive battery terminal (only when trying to crank it). Disconnected the battery and jumped it from another running vehicle straight to the cables (trying to eliminate our battery), same deal, click, no start, positive cable sparks. No noise down at the starter that we can detect.

We then started questioning our own sanity. Things like revisiting the starter wiring that we don't think we removed. Below is a pic of what we thinks is WRONG (the positive and negative should be reverse), but we can't find a decent diagram in the aftermarket manual we have for it.



So, first of all, can someone confirm that this is either right or wrong? (We did not try starting it this way.)

Secondly, any ideas on what we might be fighting. The new engine is not frozen, we can turn it with a wrench.

Headlights and most other electricals seem to work. This battery and starter used to work with the other engine. Ideas are appreciated.

 

Sounds like when the starter solenoid is being engergized by that small red
wire the battery positive terminal is being shorted to ground.

That Braided wire from the starter motor should connect to one of the solenoid lugs.
The other solenoid lug should have the positive battery cable going to it.

When the solenoid is engergized by the small red wire, power from the large Red cable should transfer 12 volts via the solenoid to the braided cable which goes to the
starter motor windings and the starter motor should spin.

Where does that Black cable come from?

If it is from the negative battery cable, connect it to the engine block.
Move the Large Red wire to where the Black cable was.

Here's the schematic for the starter.

1983 Ford Bronco Diagrams picture | SuperMotors.net

 

Thank you. That should get us going. The black cable goes to the battery, which suspected was wrong. We'll figure out where to connect on the engine block.

The linked diagrams will help immensely. We found tons of diagrams for the solenoid on the fender, but nada for the starter itself.

Thanks again for the quick reply.

 

OK, starter wiring problems fixed. Cranks and cranks and cranks, but won't start.

Best we can figure, no spark at the spark plugs, nor from the coil to the distributor. We got kinda stuck the as the Chilton's manual wasn't too helpful.

Also, a bit of history. The truck is a 92 with 4.9L, the replacement engine is a 91 4.9L. The distributor wiring connectors were different, as was the wiring harness connector to the body wiring harness. So we swapped wiring harnesses and distributors from the 92 engine over to the 91.

So, in addition to trouble-shooting the lack of spark (we do have some spare parts between the two engines, two coils, etc.) we'll have to get the distributor timed up on the new engine. Any pointers on that would be appreciated as well.

Thanks.