Sparks from the starter! Won't start...

[EZD]

New starter and battery in early summer in my well kept 1991 Explorer, as well as a new alternator recently, been starting rough lately, noticing sparking coming from underneath. It stranded me the other night, just a click coming from the relay under the hood, the next morning, fired up fine. For a few days it ran fine, but got to work this morning and tried to start it after I shut it off, and sparks coming from the starter motor, I couldn't tell from exactly where. Without proper testing, I suspect the battery is ok, which leads me to the starter. Wiring, faulty starter only six months old?

Gotta have the Sploder running reliably for my Christmas Road trip!!!

 

[Runnin'OnEmpty]

Welcome EZD.

I'd check where the positive cable attaches to the starter. Sounds like it may be (nearly) touching something to give a direct short when the starter is engaged.....Maybe you can loosen the attachment bolt, move the cable slightly, and retighten.

 

[ExplorerDMB]

that is some good advice to start out with.

-Drew

 

[410Fortune]

yes check the wiring to the starter. There are two leads, the larger wire is + directly from the battery (on some trucks from the + battery via the power distribution at the starter relay).

the small lead is the Starter signal wire form the key switch, also via the starter relay.

Your starter has another relay built into it.

the starter gets its ground from the transmission, so the engine ground strap must be attached and clean. The - cable from the battery to frame must also be in good shape.

You can test to see that you are getting 12v+ at the big red wire (all times hot) and 12 V+ frmo the smaller lead when the key is switched to start position.

I suspect faulty wiring first, but sparks always mean = dead short.

 

[EZD]

Solid advice, much appreciated, I'll start with wiring first.

Thanks everyone.