Replacing Battery Cables On A 91 Ls400

[sisterpete]

HELP!!!

both cables on my battery look as if they're the original parts... they are FULL of corrosion and need to be replaced. problem is, they disappear into a black hole, cant see where they're going.

called lexus to see if they could tell me where the other end of the cable ends up... not much help... told me the cables go into the wiring harness and that cost 1100.00 dollars to replace. HAHAHAHA

does the negative cable come from the battery and just end up at the block? nothing else in between?

Does the positive cable go somewhere else besides the starter, which is located UNDER the intake manifold. had to have it replaced a few years back and never thought of having the cable replaced at the same time. i dont know if the solenoid is on the starter or located somewhere else.

ive searched and cannot find any tutorials on this. any help would be really appreciated

thanks

[landar]

Unlike cars of the past, there are more places in which to connect than just the starter and chassis ground. Now, let's back up a moment. Are you sure that you need new cables? You can often clean the old posts and connectors to work well. And if not, the auto stores sell replacement clamps so that you basically snip off the old ones and bolt or solder on new post heads to your existing cables. See this ->

[sisterpete]

Unlike cars of the past, there are more places in which to connect than just the starter and chassis ground. Now, let's back up a moment. Are you sure that you need new cables? You can often clean the old posts and connectors to work well. And if not, the auto stores sell replacement clamps so that you basically snip off the old ones and bolt or solder on new post heads to your existing cables. See this ->

thanks... but my cables are FULL of corrosion... for several inches down inside the cable

[steve2006]

It may look unsightly but is the corrosion causing any problems electrically? It may look bad but if everything works and given the work required and the cost is it worth doing on a 20 year old car?

The wire is very thick so even if the surface is bad the inner core may be fine.

WD40 or similar is a useful anti corrosion spray which may be the other option along with some PTFE tape to prevent water getting further in.

[sisterpete]

Steve,

Thanks for the reply. Yes, they have caused problems on multiple occasions. Alternator is new, battery is new. Yes I agree, a wiring harness is NOT the answer for a 20 year old car, there is a less expensive solution to my issue. Perhaps the wd40 wil clean the inside of the cable??

It's the only car I own, still runs like a top at 300,000 + miles...

[landar]

Steve,

Thanks for the reply. Yes, they have caused problems on multiple occasions. Alternator is new, battery is new. Yes I agree, a wiring harness is NOT the answer for a 20 year old car, there is a less expensive solution to my issue. Perhaps the wd40 wil clean the inside of the cable??

It's the only car I own, still runs like a top at 300,000 + miles...

I have to respectfully disagree that WD40 will clean anything inside of your cable to make things work better. Wires, in and of themselves do not generally go bad unless they just break in two. Yes they can corrode on the surface but be fine inside. Cables are made of many strands of individual wires. The usual problem with corrosion is within the head of the large female connector which clamps to the battery. Those are usually lead connectors with the copper cable wires crimped within. You can't see that particular connection.

Sisterpete, you mention "problems on multiple occasions". Can you explain exactly what kind of electrical problems you are having? That may help in the diagnoses.

[sisterpete]

Steve,

Thanks for the reply. Yes, they have caused problems on multiple occasions. Alternator is new, battery is new. Yes I agree, a wiring harness is NOT the answer for a 20 year old car, there is a less expensive solution to my issue. Perhaps the wd40 wil clean the inside of the cable??

It's the only car I own, still runs like a top at 300,000 + miles...

I have to respectfully disagree that WD40 will clean anything inside of your cable to make things work better. Wires, in and of themselves do not generally go bad unless they just break in two. Yes they can corrode on the surface but be fine inside. Cables are made of many strands of individual wires. The usual problem with corrosion is within the head of the large female connector which clamps to the battery. Those are usually lead connectors with the copper cable wires crimped within. You can't see that particular connection.

Sisterpete, you mention "problems on multiple occasions". Can you explain exactly what kind of electrical problems you are having? That may help in the diagnoses.

right now, it's in front of my father in laws house and will not start. just like a dead battery... we tried to jump it and it wouldnt even jump, although i think somehow i wasnt getting a good connection. the engine on the good vehicle never "pulled down" like they do when you get a good connection. i didnt have a lot of time then so i just left it. i am heading that way after bit to put a meter on it and see what is going on. need to get it running for my wifes job.

on several occasions this past year, i have had this same problem, no start. once it was the battery, that's brand new now, about 6 months old. the alternator checked bad about three months ago, so that's brand new. the other times, i have had to clean a LOT of corrosion from the battery terminals. the negative cable is stripped back about 3 or 4 inches, untwisting it and every single strand inside is corroded green. the positive cable is not stripped back as far, but you can see the same thing there.

as i said, this is our only car, well i have a work van, but i am getting tired of fixing dealing with this over and over and the cables are the only thing left that i know of... and when i do take the terminals off and clean everything the thing starts...

dont mean to rant, some things just get old after a while... :o) but i could be a lot worse.... i need to keep telling myself that.

the mechanic i have taken my car to for YEARS told me he didnt work on lexus when we purchased this one about 8 years ago, so i found a new mechanic that does, but he is EXPENSIVE!!! so i am slowly becoming a shade tree mechanic... for the smaller stuff...

i took auto mechanics waaaaaaaaay back in high school, my teacher told me then that i would make a good mechanic if i worked in a dealship, some place where someone else diagnoised the problem and i just fixed it... he said, and i agree, that figuring out what the problem was, was my greatest short coming....

thanks for the help, many a forum responses have helped me out, cars, computers, etc....

[SRK]

The issue may be that the solenoid contacts in the starter motor are fried. Common problem. Turn on the headlights - if they are bright white then you know the battery is good, and that the circuit is good. If the starter clicks, or does nothing, it's more than likely the starter and not the cabling. The starter repair is easy. Getting to it is not.

[landar]

The issue may be that the solenoid contacts in the starter motor are fried. Common problem. Turn on the headlights - if they are bright white then you know the battery is good, and that the circuit is good. If the starter clicks, or does nothing, it's more than likely the starter and not the cabling. The starter repair is easy. Getting to it is not.

Yes, SRK brings up a good point. You mention that it will not start. We still need a bit more info. When it wont start, does it click multiple times in rapid succession? Or do you just get a single click each time you turn the key to the start position? If it is the latter, then, as SRK says, it is your starter. If you get multiple, rapid clicks when you turn the key to the start position, it is a bad connection or battery.

[sisterpete]

When it wont start, it clicks only once, not multiple times like when the battery is having issues... blah... so this is a new problem... and im sure after reading these last post, it must be the starter. we had it changed 3 or 4 years ago... cost 600.00 oh brother!!!!

one other thing i did notice, the other day when my wife was trying to start it, as i peeked in, i would see the instrument lights go out... like a battery would... or so i thought... yesterday when i was sitting in the car trying to start it, i noticed it was only the white speedometer and the tach that went out, then they came back on WITHOUT turning the key off and back on, the rest of the lights stayed lit.... starter....

thanks to all for your help and suggestions....

[SRK]

So remember when I said to check the headlights? You haven't done that have you? Because if the panel lights go out while cranking, well that's a discharged or damaged battery. Help us out here by acting logically and you just might fix it cheap.

Yank out the battery and have it load tested by some one who knows batteries. Sounds like a very bad cell - perhaps a grid has collapsed in the battery.

[sisterpete]

Yes, I checked the headlights, bright in broad daylight shining against my van, tried to start, one click, headlights dimmed only while trying to start, as soon as I released the they were bright again... As far as the dash lights, read again, ONLY the white speedometer & tach lights went out while trying to start, released the key & they came back on... ALL the other dash lights stayed lit... when I had battery issues before, ALL the dash lights went out and did NOT come back on until I would turn the key off & back on

[landar]

Yes, I checked the headlights, bright in broad daylight shining against my van, tried to start, one click, headlights dimmed only while trying to start, as soon as I released the they were bright again... As far as the dash lights, read again, ONLY the white speedometer & tach lights went out while trying to start, released the key & they came back on... ALL the other dash lights stayed lit... when I had battery issues before, ALL the dash lights went out and did NOT come back on until I would turn the key off & back on

It does appear to be the starter solenoid contacts that are bad which, unfortunately, means taking the intake manifold off for access. A fairly big job. I believe your lights are dimming due to the current that the starter solenoid coil is pulling. Also remember that if the car has not been started and driven for a while, the battery is naturally going to be a little drained from all the "testing". You might want to put a charger on it for now. Bad solenoid contacts will usually "make" once in a while. At least enough to start the car. If you can try 25 times and get it to start once then you know for sure it is the starter.

[curiousB]

Just makes you wonder why they didn't separate the solenoid from the starter motor given they buried it deep in the V of the engine. The solenoid is a wear out item. Instead of a simple item replacement next to the battery its major engine disassembly. Totally nuts.... "The ultimate pursuit of overly complicated repairs"

[landar]

Just makes you wonder why they didn't separate the solenoid from the starter motor given they buried it deep in the V of the engine. The solenoid is a wear out item. Instead of a simple item replacement next to the battery its major engine disassembly. Totally nuts.... "The ultimate pursuit of overly complicated repairs"

Yes, exactly. The old Fords and Chevy's used to have the solenoid mounted on the firewall, not built into the starter. If I had to visit my starter, I would seriously consider welding the solenoid contacts together and mounting a remote relay on the firewall like in the old days. The only issue I could see is that be that the motor might be torquing before the gear were thrown into the flywheel teeth. Might cause issues like grinding and premature wearing of the gears. Don't know how critical that timing is. But would like to try it.