need help fast! bad engine ground? or something else?

last night, in the middle of a shift at my second job (pizza delivery), i go to crank my jeep, the starter starts to turn, and then everything dies. this has happened once since i cleaned and changed the terminals to my battery, so i remove the (not as clean as i'd like) negative wire ends that seemed to be related to the problem, and crank the terminal down again (i do this several times, breaking the terminal wire holddown in the process-wires are mow just connected to the holes where the clamp used to be)-anyway, long story short, every time i give the negative wire giong down to the starter area a yank, power comes back, but every time i try to start it, the starter starts to turn and then all power dies again.

tried pulling the block fuse while the wires were connected but it was "dead", and the key buzz came on.

this all leads me to believe that i have an intermittent engine ground issue, one that i can get back in line by pulling things about, but as soon as the starter wiggles that engine, it dies again.

what do you guys think?

corroded/bad engine-to firewall strap? (was doing a search and this was mentioned-under the #5 plug?)

any suggestions might be helpful. if it is just a bit corroded, i figure i can yank and clean and perhaps oxgard it (another question-who carried oxgard regularly? i can't remember where i got it last time, and that tube is not around anymore) and fix the problem before i have to drive this afternoon.

quiick help would REALLY be appreciated here. thanks in advance.

You need to review how the wires work. The negative wire may appear to go down to the area of the starter, but it doesn't. The starter has two positive wires going to it -- one is the heavy, always hot wire that actually powers the starter, the other is the switched, smaller wire that activates the solenoid.

The negative wire from the battery runs to ground. The starter grounds by its attachment to the engine. It sounds like you need some new battery cables.

Well guy, it seems to me that the problem is right in front of you. When you are working with electrical systems the first and most important thing is to have clean tight connections. If you can change the problem by pulling on the negative cable that is where you must start. Check and clean and tighten all battery, starter, and ground connections.You may want to skin the insulation back alittle on the problem cable and see if the corrosion has made it's way down the cable. if so, cut it off and work with the clean section or just replace the entire cable. Corosion will kill an electrical circuit.

Try that see what happens.

Phil

already cut/cleaned the battery-side ends.

i can't wiggle any part of the cable, but pulling on it brings juice back until i try to start again, which is why i was suspecting a corroded connection that i'm missing somehow.

eagle, any suggestions as to the best place to buy a premade set of battery cables? i'm not really in the mood to get carted around to pick up welding cable and fabbing my own right now.. if i can get a ride anywhere at all. it's a bit of a walk to advance or autozone, but probably no more than an hour both ways. just trying to handle this as quickly as possible (considering just getting it towed and getting a rental since i have it on my insurance).

one more question-for eagle especially-if the cables are bad, why would pulling the block fuse give the key-in-door-open buzzer juice even when everything else is "Dead"? i'm not going to pretend not to be ignorant, and i'm not very experienced with this stuff, so i'm just going through the FSM to try to understand it and asking those of you who DO know what's up for suggestions. thanks!

defenestrate said:

one more question-for eagle especially-if the cables are bad, why would pulling the block fuse give the key-in-door-open buzzer juice even when everything else is "Dead"? i'm not going to pretend not to be ignorant, and i'm not very experienced with this stuff, so i'm just going through the FSM to try to understand it and asking those of you who DO know what's up for suggestions. thanks!

Click to expand...

Dunno.

Electrical gremlins are hard to pinpoint. I don't know a single auto tech who enjoys being handed an electrical problem to track down.

Might be that the buzzer doesn't need much juice, but the contact isn't good enough to carry any more than that trickle. Just a guess.

i would expect, then, a very dim light under the hood (it was dark).

thanks, though. i guess it will require some screwing with to get straight. will report when i do figure it out. also, i have an AW4 failure story to post here and on ju. happened this summer. doh!

put some shiny new brass terminals on the battery and got her jumped-it looks like culprit numero uno is that the battery is hosed, and i'm going to be replacing the battery cables with something a little heavier-duty (your first suggestion was at least part of what was going on, eagle-my hot cables are crispy critters! not going to play chicken and egg-the battery compartment was badly corroded a couple of months ago, and who knows how long i've been running with innefectual positive main wires? ugh!). will update if any further data seems relevant.

now to either buy or make some heavier cables and get myself a new battery..

You may want to check these out: http://www.jeepin.com/features/cables/index.asp

If you are not going to make new cables out of welding wire, this would be good. They are expensive, though.

Also, I can't help but ask....isn't an XJ an awfully expensive pizza delivery vehicle? I think the gas mileage with all the stop and go would be a real bear.

OTOH, I have an XJ, and it is just expensive all around.

I had a very similar problem. The jeep would do what you are describing. I would crank it, then nothing. The problem ended up being the wire going to the starter, the small one that engages it. I took it loose from the starter, cleaned the connects and put it back on. I know this sounds like it could not cause the problem you are describing, it was the last thing I tried. It might be worth a try, hope this helps maybe.

cherokee89 said:

You may want to check these out: http://www.jeepin.com/features/cables/index.asp

Also, I can't help but ask....isn't an XJ an awfully expensive pizza delivery vehicle? I think the gas mileage with all the stop and go would be a real bear.

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i get maybe 15mpg when doing mostly delivery driving (the stop and go and idling time can definately suck it down-on the other hand, i keep it reasonably well-maintained and generally break 20mpg on the highway, so it's not in bad shape from the pizza/etc delivery jobs i've had since i got it), but it's my secondary job and i don't work too many hours. also, i don't have another vehicle. at the time i started there, i had just been shafted by a place i had been working at for a couple of years whose new owners ran it into the ground. was doing delivery at night and sometimes at lunch as well as PR/marketing/sales for hotels. pizza delivery jobs are easier to find than IT jobs around here, which is where i have most of my work experience. i'm going to be ditching the delivery job and moving the primary job with me when i go up to PA for the winter and do some IT work.

thanks for the link. i'd forgotten to check jeepin.com for data on cables. i'm thinking that 2/0 wiring, while cool, is probably overkill, and at that pricepoint, i think i'd be happy if i could put a set of 4GA in-not to mention that i already have fine terminals after replacing the standard ones that i destroyed with brass.

junkxj said:

I had a very similar problem. The jeep would do what you are describing. I would crank it, then nothing. The problem ended up being the wire going to the starter, the small one that engages it. I took it loose from the starter, cleaned the connects and put it back on. I know this sounds like it could not cause the problem you are describing, it was the last thing I tried. It might be worth a try, hope this helps maybe.

Click to expand...

thanks for the feedback. i'm planning on getting some oxgard, replacing the primary battery cableset, and cleaning/replacing anything that stands out. might be getting a new headlight switch/harness, too, if i ever make it out to the dealer to pick up those oil filter adapter o-rings that prefer covering the starter with oil to actually sealing the components properly.

Also when grounds start going bad electricity starts to find other routes to ground. In a cooling system that has water content with high mineral levels it can start to find that ckt in the cooling system and can actually cause a plating effect on the components in the cooling system.
That is one of the main reasons for using distilled water.