Starter Electrical Question
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Laughing Gas
Joined: Jan 2006
Posts: 1,098
Likes: 11
From: Minnesota
Starter Electrical Question
Finished a job today, came out, truck just clicked. Has been fine. Battery terminals clean, all the basics covered. Pouring down rain. As a last effort, crawled underneath and saw the main cable rusted off the starter. Crawled back out, turned the ignition on, crawled back under and touched the busted lead on the other hot terminal on the starter...truck spun over and started. Drove home, got dry clothes, finished my service calls...left truck running. Got home tonight, was able to get a new eyelet crimped on the end...all is good for now...Can someone explain the process of events as you turn the key. I see the main cable from the battery goes to a relay on the firewall. A small wire must move 12 volts to the other lug, which in turns travel to the starter. But at the starter there is another relay like that one...one small wire, and the main battery wire. Why does it have two relays...Thanks.....Spotty
!998 F-150...4.6...
!998 F-150...4.6...
Moderator
Joined: Dec 2001
Posts: 22,436
Likes: 17
From: Louisville,Ky.
Main power goes to firewall solenoid and large terminal on starter. When the key is turned, the firewall solenoid sends 12V to the small wire on the starter to engage the solenoid on the starter. This is so that most of the extra power wires can be attached to the upper solenoid battery cable and not have to be run down by the engine/exhaust to the starter.
Not sure why they made it so complicated.
Not sure why they made it so complicated.
Thread Starter
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Laughing Gas
Joined: Jan 2006
Posts: 1,098
Likes: 11
From: Minnesota
So...The cable at the starter is always hot? So...the relay on the firewall does not move 12 volts from the battery side to the starter side cable?...must not if always hot. Does the small wire on the top relay go to the small wire on the starter? I wonder why they just didn't put multiple wires on 12 positive and eliminate that top junction. I think if my repair does not hold up, I'll just run a seperate new cable from the starter to the top relay, cut both ends off the bad and leave it in that wrapped up mess.
Thanks guys...
Thanks guys...
Moderator
Joined: Dec 2001
Posts: 22,436
Likes: 17
From: Louisville,Ky.
Yep, top solenoid just sends power to the small wire on the starter, the big one is always hot.
I converted my 88 Mustang to this set-up because those small starters have more torque and draw less amps than the old style Ford starters with no solenoid on them. They are lighter too
I converted my 88 Mustang to this set-up because those small starters have more torque and draw less amps than the old style Ford starters with no solenoid on them. They are lighter too
