Outer Limits 4x4 Board

My windscreen wipers struggle to move on a dry windscreen and my headlights look like candles with the engine running and the new battery.

I know hilux's havent got the best of headlights to start with but they are terrible.

Could this be maybe a bad or or what else could it be?

Often windscreen wipers will struggle on a dry surface as the dry surface offers quite a great deal of resistance...specially if the spring that applies pressure to the windscreen is strong. However a poor earth may also cause this to happen.

The head lights problem tends to suggerst that in there case it is a poor earth problem..............

Check the lead where it is attached to the battery........also the where the lead goes into the connector..........then to the eyelet that is at the other end..........and of course the way the eyelet is attached........check these for rust as well.

Make any necessary repairs.

If the problem still exists then find out at what point your headlights are earthed and check that as well..........and of course also ur wipers.

Generally if u have a earth prob then it will also make the car hard to start.

Have u been doing any wiring to the car???...........is it possible u have screwed something up???

An auto electrician done some work to it last year and it hasn't glowed since. He told me that I had fried the glow-plug solenoid but I've sorted that out and it still doesn't glow.

There is some probs atm with the combo switch etc, its just my next project to fix but somehow theres a few things wrong but they all don't seem to be related if that makes any sense, the headlights and wipers being just the first part I would like to fix.

My parents have the same model lux and its lights are brighter and their wipers have alot more power....

two options to help.
The way you check for bad earths is by using a voltmeter selected to volts and puting one lead on the negetive terminal and the other to the car body, headlight frame ect whateve. The meter should read zero as there should not be a voltage drop.

They should be at the same potential.

If you get a reading, say two volts,. this is how much power you are losing on the positive. eg it should read less then half a volt.

By placing one lead on the negetive turminal and moving the other to the steelwork of all components you can locate where it is.

The second option is to just run a new wire from the negetive on the battery to the lights or whatever and see if this fixes the problem.
Steve

It doesn't have to be on the negative side (although this is most likely.)

Are they both fed by the same fuse? I recently had a fuse corrode in its holder, took out the radio and the clock in the dash. A bit of crud between fuse and holder can add resistance to the joint - or a high resistance joint could be anywhere else in the circuit.

Good luck,

Scott

To state the obviouse - or not
It is the same with the positive.
Voltmeter on either side of , say fuse should read zero volts.
What ever you read is your losses. eg there is resistance in the joint.
steve

Sorry Bruiser but thats just not right at all.

Firstly its a multimeter your thinking of.

Secondly if you follow what your saying then you will always get a reading of zero..........By touching both terminals to earth......can only give zero.........its not actually reading anything.



However your second suggestion of running an earth direct.......as a means of testing.....will work and is a very good suggestion as it will effectively determine one way or the other if thats his prob or not.

Sorry Top Cat - bruiser is right. Try reading his post again?

A voltmeter will do what he describes. Most people own a multimeter, so called because it measures a multitude of parameters, voltage being just one.

Not all points in an "earth" network are necessarily the same potential. Ulitmately all current leaves the battery thru the positive terminal and returns through the negative terminal. Where it goes in between is what we're talking about. Ohm's Law says that where you have a current flowing through a conductor which has intrinsic resistance (which, on a car, is all of them) you will drop potential - i.e. you get a voltage drop across the resistance.

When we are talking about items such as headlights or windscreen wipers there are typically a number of connections between the "negative" connection on the item itself, and the negative terminal of the battery. Every single wire, crimp, plug or socket in that circuit WILL produce a voltage drop. Most voltmeters/multimeters won't register it on a 20V range, and some may not detect it on their most sensitive setting, but that voltage drop IS there. Most of the time it is (by design) insignificant.

The point bruiser was making, which you appear to have missed, is that IF you measure a voltage drop across part of this "earth" with your volt/multimeter on a 20V scale, you have a problem.

Of course, if bruiser was saying something different, I'm happy to stand corrected.

Cheers,

Scott

Alright before we go any further here.

The vehicle we are talking about does have the normal negative ground doesnt it????


Now Im not aware of any vehicle nowadays that has a positive ground but your ideas would definitely work in that scenario........

Actually the post still doesnt make sense even if the Hilux is positively earthed.

Anyways........here is what I believe should be happening.

Take your Volt meter and measure the voltage of the battery by placing a probe on each terminal.

Lets assume that is 12.5

Now (In a Negatively earthed car) place one probe on the positive terminal and the other probe on the body of the car. (In a Positively earthed car, put the first probe on the Negative terminal of the battery.)

The measurement from this should be pretty much the same.....

If there is a reasonable discrepancy then yes it suggests that there is a problem.

And yes as already suggested by placing the ground probe at different points on the body of the car, you may well get different readings.



It should be noted however that I would NOT reccomend this as a good method of determining if you have a good earth connection or not.

The reason?........because it is quite possible that even a very poor connection will provide a 12V reading, however that does not mean that you will be able to draw the necessary Amperage through that poor connection.

You should be checking for voltage drops with the current being drawn by the windscreen wiper motor (or whatever else you're fault finding)- it's pointless doing voltage drop checks if there's no current being drawn!!!

Don't forget you will get voltage drops in the wiring from the positive to the load AND in the earth wire/ chassis back to the battery negative. So check both sides for losses.

Thanks David - I thought I woke up on a different planet or something!

Like I said champ, Im not after an argument.

Maybe there is a communication break down..........I have no idea.

Fact is that myself and all the sparkies I work with are quite confident of what I am trying to explain.

And we are rather happy that we do all the work on our vehicles

Top Cat wrote: Maybe there is a communication break down..........I have no idea.

Yep! Communication break down - and I'll give you the benefit of the doubt...

If your test works for you, I'm happy for you - but the test you have described is essentially a coarse test. If you have a BIG problem you should find it quickly. For the type of fault we've been talking about here you need to look for voltage drop across a connection as current is flowing i.e. with the load switched on. Depending upon the size of the unwanted resistance your test may or may not find it. The test David and I are proposing is much more likely to find it.

Regardless of how he identifies the problem, perhaps h-n-m can tell us what fixed it?

Cheers,

Scott

LOL..........actually I didnt really offer an option..........all I was trying to do was to work out what u were on about.

And I agree..........as stated earlier.........I would not reccomend it.

I have set a land-mine here guys havent I

I have tomorrow off and so long as the weather id right(vehicle outside) I shall follow this thread and have a response hopefully.

Argue on guys cause I am learning heaps from this banter, it's great