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Power Loss When Attempting Start

871 Views 23 Replies 11 Participants Last post by  mightybg
I am at a loss because I cannot seem to find the right info. Alternator correct and good. Battery charged and good. Starter correct and good. Every single time I try to start this 1996 ZJ 5.2, it clicks once, sometimes twice, and then all power is cut. I let it rest for sometimes 2 minutes, and then sometimes 45, and power will come back. Point is power goes away when I try to start it, and then it eventually comes back. Where is this breaker that keeps popping? It doesn't seem like wiring connections would be causing this problem. I'm at a loss, and I'm just trying to drive this out to work on someone else's car....
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Discussion Starter · #6 ·
I'll add that I checked the resistance between the outside of the battery terminals and the battery posts, and there is no electrical resistance. I checked that there is 12.5 volts being supplied to the fuse box as well.
 

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Put a jumper cable from the battery negative to engine block but not where the factory cable attaches. If it starts then check the cable for voltage drop or damage. In case there is broken plates in the battery, keep away from the top of it. I had a brand new one that someone dropped. They went to start it complaining it was a bad starter motor and the battery erupted in a ball of fire, showering me with acid.
 

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Discussion Starter · #9 ·
Put a jumper cable from the battery negative to engine block but not where the factory cable attaches. If it starts then check the cable for voltage drop.
How would a bad cable cause circuit breaker type symptoms? The power always comes back, but it just never seems to be able to start, and then it always temporarily loses all electrical power. I'm still learning electrical diag, so an explanation would be appreciated.
 

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How would a bad cable cause circuit breaker type symptoms? The power always comes back, but it just never seems to be able to start, and then it always temporarily loses all electrical power. I'm still learning electrical diag, so an explanation would be appreciated.
Loose connection at the block with oil, corrosion, etc causes the pop then the connection cools off and suddenly it’s ready to go till you hit the key.
It’s an expansion then contraction thing. Aside from that, a seized motor could cause the ASD relay to pop open. Anti-theft or radio hooked up wrong can even trigger it.
The most common one is corrosion between the clamp and battery post. Lead oxide (lead rust) is one of the worst things to pass power through. It’s better at insulation when heated up than allowing power out. It sometimes turns into a giant diode or circuit breaker-like connection. It will sometimes work when dry for a couple days.
The best test is remove the battery clamps and buff up the contact surfaces. 9 out of ten times it will be the positive terminal to post. I used to have a video on it posted but they all disappeared in 2016.
 

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Discussion Starter · #11 ·
Loose connection at the block with oil, corrosion, etc causes the pop then the connection cools off and suddenly it’s ready to go till you hit the key.
It’s an expansion then contraction thing. Aside from that, a seized motor could cause the ASD relay to pop open. Anti-theft or radio hooked up wrong can even trigger it.
The most common one is corrosion between the clamp and battery post. Lead oxide (lead rust) is one of the worst things to pass power through. It’s better at insulation when heated up than allowing power out. It sometimes turns into a giant diode or circuit breaker-like connection. It will sometimes work when dry for a couple days.
The best test is remove the battery clamps and buff up the contact surfaces. 9 out of ten times it will be the positive terminal to post. I used to have a video on it posted but they all disappeared in 2016.
Okay. I will give that a try. I'll keep this thread updated.
 

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I am at a loss because I cannot seem to find the right info. Alternator correct and good. Battery charged and good. Starter correct and good. Every single time I try to start this 1996 ZJ 5.2, it clicks once, sometimes twice, and then all power is cut. I let it rest for sometimes 2 minutes, and then sometimes 45, and power will come back. Point is power goes away when I try to start it, and then it eventually comes back. Where is this breaker that keeps popping? It doesn't seem like wiring connections would be causing this problem. I'm at a loss, and I'm just trying to drive this out to work on someone else's car....
 

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I can almost guarantee you that carnuck, HighLonesome, and TB1960 are right. It's not a breaker, it's a bad connection somewhere. I had a problem with my negative battery cable. It wasn't melted like TB1960's was, but rather it was corroded real bad up inside the insulation. I also had a starter issue that acted similarly. (As a note about the starter, I've seen people say on here that these starters actually very rarely go bad and that the usual problem is simply that it has gotten oily & grimy so that the solenoid sticks, or the wiring connections get corroded.)

There are 3 main engine harness grounds, one to the fender beside the battery, one to the engine block by the coil, and one under the oil dipstick attachment bracket. Wire brush or sand or otherwise clean them to "shiny" condition. If it has replacement battery terminals, especially the standard cheap clamp-on type, you should probably take them loose and check for corrosion. Maybe check the alternator connections as well, if you didn't already. Battery cables & terminals, connection at the starter, 3 grounds, connections at alternator . . . that should get you sufficient power to the starter, assuming the battery isn't fooling you and is actually weak when a load is applied. Also, I have seen people post that they've had corrosion or oxidation problems on the main connections to the Power Distribution Center ("PDC", the little plastic box behind the battery that has the fuses and relays) and also on the prongs of relays or fuses where they plug into the box. If you have access to one of those clip-on remote starter button thingies you can connect the battery directly to the starter and see if they both work that way.
 

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Allow me to ramble.
I am somewhat fascinated by this.
I get the impression that when the attempt to start is done and the load is applied to the starter, there is loss of power that returns after while.
That, to me, looks like some sort of thermal breaker. Not a fuse.
As mentioned, there are some types of corrosion that can cause behavior (behaviour) like this.
A long long time ago (in cars) there were some circuits that had "breakers" and not fuses that would behave like this.
If using a "remote starter button" ( or the old trusty heavy screwdriver) does not confirm that the starter is good, then I would have another think about the cause.
Fuses do not reset. Period.
Thermal breakers do reset.
Should we be looking at this?
Thermal breakers do go bad.
The question would still remain.
Why is the load causing the "break".
Bad "Protection" or "high load".
My way of thinking:
If the starter is bad and has a burnt armature, field coil or bad brushes, that should not cause a high load.
It just would not turn.
What would cause the high load?
I guess a short would cause that but, and I think most would agree, a short in the starter or starter circuit is unusual.
Do we look at the load or the protection?
Well, both I guess.
 

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I'll add that I checked the resistance between the outside of the battery terminals and the battery posts, and there is no electrical resistance. I checked that there is 12.5 volts being supplied to the fuse box as well.
When you check with a good meter, there is almost no load, it's in the megohms, to drag the voltage down. so it's roughly equivalent to checking right across the battery terminals.
The starter circuit is isolated from all the other electrical in your ZJ, and easily draws way, way more current than everything else combined when you're trying to start.
When a starter clicks only, that's the starter solenoid not getting enough juice. Maybe you can artfully parallel some jumper cables with the stock battery cables and try it. The good side of this is when cables go bad, they don't really harm anything, they just don't work. So they can stay there while you parallel (replace temporarily) them.
 

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I'd agree with everyone saying it's a bad connection. I had these exact symptoms on my 1996 corvette just a few months ago (trying to start would cause entire car to go dark) and it was fixed by tightening some grounds and replacing my corroded terminal bolts. I know, I was amazed as well because I thought it had to be some kind of gremlin in the wiring too.
 
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