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Electrical - no start, please help

3K views 34 replies 13 participants last post by  78BroncoSteve 
#1 ·
I have a no start issue. When I put my battery back in so I can start it, my mind was on other things and I stupidly hooked the + cable to - terminal and - cable to + terminal. My starter relay smoked. It was hooked up for about 1 second.

I replaced the starter relay. Hooked things up properly and nothing, no start. I could here something click (starter solenoid I guess) immediately when I hooked up the battery. I am getting the "BRAKE" idiot light illuminating when I try to start, but nothing else. It's like the battery is totally dead.

So, I just took my battery to Autozone to have it checked for charge. It's a 2.5 year old Optima Redtop. The Autozne guy just looked at my receipt and handed me a brand new one. So, my battery is brand new.

I just hooked up my new battery (I even did it correctly this time!) and the exact same sequence of events and conditions above is happening. In other words, zero difference.

I'm scared here guys. What did I fry??? Do I need to also try a new voltage regulator? New starter maybe, seeing as the starter doesn't even try to turn the engine over???

Please help!!!! Thanks as always.

EDIT: I'll be reading through this in the meantime

http://www.fullsizebronco.com/forum/21-noobie-bronco-tech-questions-flame-free-zone/449441-bronco-wont-start.html#post6427978

That said, nothing just failed here, I caused the issue, so looking for help from that angle. I'm not good with electrical diag
 
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#29 ·
You obviously have a good starter, because it is engaging fine. The problem is it is getting power when it is not supposed to. Like mentioned before in this thread, your solenoid should only have power on the starter side when the key is in "Start". With the battery disconnected, pull the starter cable off the solenoid. Reconnect the battery and check for power using a multi-meter on the starter side of the solenoid with the key "Off", there shouldn't be any power but it sounds like on yours there is. Try tapping the solenoid with a wrench or screwdriver and see if it is just stuck and check for power again. If you still have power, then I would say either your ignition switch itself is bad, or the solenoid is bad. This is assuming you truly did hook up the two signal wires with the 90 degree boots on them correctly. I, like many others, have gone through multiple of those solenoids but once you get a good one it will last forever it seems.
 
#30 ·
Thank you guys for the replys. I'm going to troubleshoot all this on Friday. I went ahead and paid extra for a Motorcraft starter relay/solenoid so I now have a known good unit.

The two wires with the 90 degree boots are hooked correctly. I took pics of the original setup and did an immediate swap from the relay I fried to a new auto parts store one. Everything is on per the original setup only now I have the black/yellow extra wire on the + side of the relay due to my LEB 3G setup I went to.

It seems it has to be either the relay or maybe the starter cable is bad. I'll replace both with quality new parts and see.

Again, my ignition switch is completely unplugged and removed currently, so it shouldn't be getting a singal to engage the starter except from the relay.

The Motorcraft relay is substantially heavier than the Chinese one from O'Reilly's. Maybe it'll hold up.
 
#31 ·
This test could save you a lot of time..

Just curious how things turned out?
If no progress try this.
1.Disconnect the "negative" cable to the battery for testing purposes.
2.Disconnect the "S" and "R" terminal wires going to the solenoid.
3.The "positive" battery cable must always remain connected to the solenoid.

We can verify several things with this setup,
and it will also prevent your starter from engaging while troubleshooting
due to the ground cable being disconnected.

Everything you test with your voltmeter will be connected in this way above.
1. the black ground voltmeter lead must "always" be connected to the negative battery post. (A light clamp on item may be needed).
2. After making the above mentioned changes, first connect the voltmeter to see if you have 12volts on the downstream side(to the starter) from the solenoid.
2a. If yes? stop there replace your solenoid. There still could be other problems. But the solenoid needs replaced first.
IF No voltage? then proceed to step 3.
3. Connect the voltmeter to the "S" terminal wire which is disconnected from the solenoid. If voltage is present with ignition off or disconnected? Then you have found a problem. Also check your "R" terminal wire as well. Then get back us with your test results. I have my suspicions but don't want to get ahead of what needs to happen first.;)
 
#32 ·
Thanks for that awesome troubleshoot write up. Fortunately I have it fixed up. Shortly after my post above, I installed the new starter relay and all was right and good in the world again. Vehicle starts and stops like normal, the 3G is bad ass and charging my battery very well.

I have my RedHead box all bled and am now working on installing my new tie rod assembly and adjustable drag link set up (all Moog parts from WH). Than I'm ready to go.

I've been away for a while though as we just had our 2nd baby (another boy) on Friday 3/31. Before that I was covered up with work.

We'll see how baby number 2 incorporates but I hope my Bronco doesn't end up just sitting around now.....or end up for sale. It's not money but a time thing. Maybe I'll pickle it for a while....again, we'll see.
 
#34 ·
Stay at it long enough to have the kids fall in love with "Daddy's Bronco". I have an 8, 5 and just shy of 2 year old and they all love the Bronco. I shout "Bronco" and they reply "Round Up!". It even serves as a quasi baby sitter in that I let my youngest hang out in it when I tinker outside with it. This usually lasts 15 mins to get at least something done before he does something destructive - I guess rear view mirrors are not strong enough to hang from!

#1 is keep it on the road (and in the garage when not in use) - I had long periods of time where it was down for major maintenance and it became a drag at times.
 
#35 ·
Thanks guys. My 3 yr old is definitely in love with it, so that's good. Maybe my lack of actual sleep over the last several days is causing me to be dramatic.

That said, I've gotten this Bronco pretty fixed up and hope to continue to do so, it's just finding the time to do will be substantially harder, but we all figure it out.

Oh well, I'm glad I was able to sort through this electrical problem thanks to you guys!
 
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