91 S-10 Blazer, no headlights & no power to fuel pump,

What's worse it's an intermittent problem and don't trust it any further than I can push it 'Bout two weeks it started fine, but when I turned on the lights, the
engine died--no fuel to the TBI Didn't make the connection for a while as I swapped fuel pumps and everything was fine (for a while) Died again a few miles from home and this time I noticed no headlights, no tail lights, no interior lights, no fuel pump, but will still crank. Towed it home and discovered the fuel pump would work when connected to a 12V source Swapped the headlight switch....... no luck Took apart the engine wiring harness to the fuse block, didn't see any corrosion and everything worked again until yesterday Have power thru the fuse block from the two hot wires Plan on going out today to check on just fuses which have power and which don't with ign switch on.
Anyone else ever have this c**p happen to 'em? Must be a short somewhere but where?
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Ken wrote:

Take a good look at the condition of the connections at grounding points, particularly where a cable is grounded to the frame. Corrosion is sometimes hard to detect and it can drive you to wit's end. Also, inspect the negative battery cable terminal. I've seen corrosion build up beneath the insulation (where it's nearly impossible to detect) and cause a poor electrical connection. Good luck.
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Thanks for the reply
Finally found the problem after taking out the entire dash. (Like they say: "Kids, don't try this at home") Turned out one of the two hot wires in the connection block between the engine wiring harness, thru the firewall and into the fuse block just decided not to connect. Nothing was visibly fried, corroded, broken or otherwise fouled, but still....
Picked up another wire and connectors from the local Pick n Pull and swapped 'em. Only took about 5 hours to get everything back together. I'd hate to see what a shop would have charged me to find n fix it. Probably would have sold me an entire wiring harness, but wouldn't have taken two weeks to figure it out
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I have seen that a couple times. The usual problem is that the pins didn't get seated fully when the harness was made. When first built they connect but a few years of hot/cold cycles and rough roads and they become intermittent. It's a PIA to find, because as you discovered with yours. Nothing looks like it's messed up in the block. I have also seen more than one where the fuse connectors LOOK fine but they no longer pass current. Pull the fuse block and they still look OK until you actually test the clips.
--
Steve W.
Near Cooperstown, New York
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I'm just happy it happened in front of my house, and not where we camp in the Sierra Nevadas, 10 miles from the nearest paved road
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