[Santos]

Like the title says. I will try to include as much info as i can so the sparkies among us can throw in troubleshooting questions

Stock car, hasn't had any trouble in the past. Its got stock electircal set up (no kick arse soundsytems, winches, spotties, nADA!)

Two week as ago i installled a new rebuilt carb. Used all existing electical sensors on the vehicle
Went to stockton on the sunday, did have the acc fuse blow instantly 3 times up there when i had the gps and stereo on, the following tuesday started notice the car was turniong itself off occasionally.
By the thursday the Battery was dead, barely made it home. One broken positive terminal and i drove 30kms @ 5000rpm in low gear to keep it alive. The altinator was runing unconnected.

Tried swapping out the battery. Kept dieing. Finally get a 15.5v reading then a 11v reading from the alternator. Figure its a dead regulator and swap in another one from the lwb on the saturday. Also replaced broken terminal with new one. New altenator gives 13.7v when connected to recharge battery and 14.5v when running unconnected. Rev it, no increase in voltage. Have been keeping an eye on it with the multimeter, all saturday, sunday and monday.

Head out to the city today, get there didn't check it. On the way home i realised straight awya the windscreen wipers are sluggish. Limp 40kms with no headlights and make it on battery charge alone.

Multimeter reading was 5v on the unconnected altinator at idle. (vs 9v when connected to the battery.)

Went to my mothers where the other battery had been recharging, was full car ran fine off battery made it one block from home before the battery could not support the lights (only 5kms)
I would say that battery is fried and the other one i left on the charger is most likely had it.


I am going to get a supercheap battery by next week so i have a new one, (the one that got me home from the city is 2years old and was supposed to be a 3 month tie me over when the expensive battery died) also really need a V-pulley Vitara or Sierra alternator that is working condition. It is possible thats its just bad luck. The 2nd alternator i put in was from a car tha has been sitting in a shed for 15 years.I going to getsome goldplated terminals next week too.

i thought it might be sand but i swapped the alternator??????? what else could sand get in?

[MacDaddy]

Just a guess, but it sounds like you have a Negative/Ground fault to me, it charges ok cold, but warm or hot, nothing...
Do you know how to use a Multimeter for resistance ?
Take both leads of battery, check that the Negative terminal is grounded to the chassis properly, with the resistance mode on the meter, if you get any number other that 0 then you have a problem... but i would check the grounding mount as well, it may have rust or crap between it, that is causing it to disconnect sometimes...

Hope that helps... Goodluck !

[PJ.zook]

As MacBear says, it sounds like you may have a ground problem.
Are any of the terminals on back of alternator getting hot, or the ground cable at all?

[royce]

Dont run an alternator with no battery connected, it kills the diodes, jsut like you have found out

[JrZook]

royce wrote:

Dont run an alternator with no battery connected, it kills the diodes, jsut like you have found out

x2, dont disconnect to check!!

[MacDaddy]

MacBear wrote:

Just a guess, but it sounds like you have a Negative/Ground fault to me, it charges ok cold, but warm or hot, nothing...
Do you know how to use a Multimeter for resistance ?
Take both leads of battery, check that the Negative terminal is grounded to the chassis properly, with the resistance mode on the meter, if you get any number other that 0 then you have a problem... but i would check the grounding mount as well, it may have rust or crap between it, that is causing it to disconnect sometimes...

Hope that helps... Goodluck !

Ooops, should have made that clearer... nope didnt mean have the engine running when taking the battery leads off to check resistance... definitely DONT have the engine running... you are checking ground/negative resistance, from the battery lead, not alternator charge...

[Ben_Sierra]

Also, you'll be lucky to get zero on a multimeter, especially a cheap one... Press the two probes together and you'll get a non-zero reading....

[MacDaddy]

Ben_Sierra wrote:

Also, you'll be lucky to get zero on a multimeter, especially a cheap one... Press the two probes together and you'll get a non-zero reading....

Yep thats what he wants to see on the multimeter, if there is any number at all, it means it has a bad connection...

[Ben_Sierra]

No, you will almost never see zero on a meter... On most meters I've seen even when the probes are pressed together they still read 0.1 or 0.2 Ohms...

[royce]

dont touch the probes with your fingers, reads the electricity in your fingers as resistance

[MART]

Most good quality meters , say over a $150 , will read 0.000 when the probes are shorted , it sounds like your original alternator died and if it wasn't you killed it by running it without a battery. The second alternator , I assume not new , sounds like the guys are on the right track with the resistance on the negative , also causing it to fail while running with battery disconnected , also check the engine bay wiring for chafing , or hardening and cracking of the insulation , exposing the copper wiring , Cheers Paul.

[foonji]

Ben_Sierra wrote:

No, you will almost never see zero on a meter... On most meters I've seen even when the probes are pressed together they still read 0.1 or 0.2 Ohms...

My fluke reads 0.

[Ben_Sierra]

Ok, maybe if you have a fluke or similar quality, but most home mechanics dont....

[MacDaddy]

Ben_Sierra wrote:

No, you will almost never see zero on a meter... On most meters I've seen even when the probes are pressed together they still read 0.1 or 0.2 Ohms...

It depends if its set to read on 20 or 2000 or 200000, or even 200000 on some...

[MacDaddy]

foonji wrote:

Ben_Sierra wrote:

No, you will almost never see zero on a meter... On most meters I've seen even when the probes are pressed together they still read 0.1 or 0.2 Ohms...

My fluke reads 0.

Yep used to have a Fluke Multimeter and Tong Tester, its amazing how quickly they grow legs and walk off... ... but if i have a cheap $20 one, it stays where it is...

[MacDaddy]

royce wrote:

dont touch the probes with your fingers, reads the electricity in your fingers as resistance

When i was doing my Apprenticeship, many moons ago now, they gave us a Body resistance test... if our body has over 200,000, you should survive an electric shock, as the electricity flows over the body surface, rather then going through it internally... if under 200,000, well... not so good...
I measured 250,000... and i have had a half dozen big shocks in my time, and many small ones... i am still here to tell the story...

[Santos]

I have two multimeters, a Digitor Automotive multimeter (which has no ohms reading) and a DSE multimeter. it gives a 1 reading in the left side of the screen when you touch the probes.
I am seriously thinking about gettting a $50 autoranging DSE one to leave in the car. It does ohms, volts, frequency, continuity, and something else. The RPM can be read with frequency.

well an update.
I disconnected the solid brass terminals and refitted... now get 11v reading from the alternator instead of 5v... but i reckon i still fried the regulator

The battery i thought was dead isn't and got me to work, rotated it out with the other one i had charging overnight. Hopefully will have it sorted out over the long weekend.

I have seen nippon denso regulators new from the states for au$29 + shipping. I am considering pulling off the multi-v pulley of the baleno alternator i have kicking around and putting the single from my original alternator. Then swap it back when the alternator arrives. (jus scared i will fry the baleno one intended for my motor build)

[Santos]

Got a fresh gold plated positive terminal from jaycar (with voltage display)

Went over everything checked earths, cleaned wires... did everything.


Then noticed my alternator belt was loose
Undid the bolts, removed the slack tightened up extra tight and the damn thing works now under load and is registering as charging.

Theory: Since the regulator went on the other one and the positive terminal terminal broke i ASSUMEd the second regulator had fried..

I will be ordering a spare regulator fo go in the expeditions kit

[MacDaddy]

Santos wrote:

Then noticed my alternator belt was loose
Undid the bolts, removed the slack tightened up extra tight and the damn thing works now under load and is registering as charging.

Ah Haaa.... dont you hate it when that happens... you spend $$$ to fix it, then find it was just something as simple as a loose belt... oh well... it fixed for now

[Santos]

yeah i feel extremely stupid

but i did sor out a few 'i'll get round to it but this will do for now' things

but i have been giggling to myself all afternoon

[MART]

Good to see you sorted it , now go buy 2 new belts , replace the one on the car and keep a spare , Cheers Paul.