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Electrical issue-no power

70Sport

Full Member
Joined
Mar 7, 2002
Messages
256
Loc.
Santa Cruz, CA
I am doing a efi swap right now and got it fired up this morning and drove around for a little while, ran good. Then get home to start cleaning up the wiring routing and such and drop a wrench right onto the ground strap on the starter relay. It sparks. Damn forgot to disconnect the battery. Anyways, put the finishing touches under hood tonight and go to fire it up and nothing. No power at all. No headlights, no click, nothing. Checked fuses and look fine. battery has 12v, starter relay has 12v.

What did I do?

I'm bummed. Was gonna drive it all day tomorrow.

Thanks
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
51,618
Stock chassis wiring harness still? If so, you might have blown the fusible link in the Black w/red wire that powers the whole truck.
That would explain the no-power to anything result.

What ground strap for the starter relay? Did you put one in yourself? Is this a non-stock wiring harness?

Paul
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,448
The battery side of the solenoid has a fusible link leading to the 10g wire that powers everything inside. It's probably burnt up. Parts stores have them. Ask for a 16g fusible link.
 
OP
OP
7

70Sport

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Joined
Mar 7, 2002
Messages
256
Loc.
Santa Cruz, CA
Its the stock wiring harness with a RJM efi harness. I have a ground strap going from the block, where the battery ground is, to the fender well on the starter relay. It's been there for years, is that not right?

So the fusible link is on the positive side of the solenoid? This might be a stupid question, but how do I replace that? It looks like it goes right into the wrapped up harness where the old alternator plug is.

Thanks
 

Viperwolf1

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Messages
24,448
Unwrap the harness. There might be a yellow butt connector attaching it to the 10g wire.
 
OP
OP
7

70Sport

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Joined
Mar 7, 2002
Messages
256
Loc.
Santa Cruz, CA
Good call! Yellow and black wire into a butt connector with the black coming out the other end to the solenoid. So I get the 16g fusible link at the parts store and hook it up?

Thanks again
 
OP
OP
7

70Sport

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Joined
Mar 7, 2002
Messages
256
Loc.
Santa Cruz, CA
Got it fixed, thanks VW1 and dirt donk for the help!

I still have two other issues to fix. First is that it fires right up when cold but cranks very slowly when warmed up and I try to restart. Kinda like a dead battery but battery is good and alt is charging it.

Could this be a ground issue? What and where should my grounds be?
 

Viperwolf1

Contributor
electron whisperer
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Aug 23, 2007
Messages
24,448
Could be either battery cable or the connections. Negative cable needs to go to a bare spot on the block or head. Swollen insulation at the cable ends indicates a bad cable. Stiff cables are bad. Corroded terminals are bad.
 
OP
OP
7

70Sport

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Joined
Mar 7, 2002
Messages
256
Loc.
Santa Cruz, CA
Everything is pretty clean. I have the negative cable going to the block, cable from starter to solenoid, and a braided strap from block to fender well. I was thinking of replacing the strap with a heavier gauge cable from block to frame? Would that make a difference?
 

Viperwolf1

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electron whisperer
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Messages
24,448
It won't make a difference if it's cranking. If it doesn't crank it may make a difference.
 

DirtDonk

Contributor
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Messages
51,618
Is this a new or old starter?
If old, how old?
Original style, or late model PMGR (mini) starter?
And if old too, how clean is the mating surface between the engine and starter?
Are you sporting headers? If so, how close are they to the starter motor?

Also, what is your base ignition timing set at? Approx. 6° BTDC is stock, 10 to 12 is a commonly used upgrade, 14 to 17 and you're getting into that area where more stress is pushing against the starter motor, and can cause a slow-start issue.

A few things to think about.

Paul
 
OP
OP
7

70Sport

Full Member
Joined
Mar 7, 2002
Messages
256
Loc.
Santa Cruz, CA
Older style starter probably like 5 years old. Pretty clean surface. I have WH shorty headers, base timing is set at 10*btdc.

I am going to clean all ground connections tonight. Also, probably move the braided strap from the fender well to the firewall and connect to intake like the mustang I pulled everything from.

Thanks again.
 
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