Strange intermittent electrical fault

[Chopperlamb]

Hi guys (and gals),

I just wondered if you could shed some light on my electrical problem as I have never come across this before.

I have had this problem since I bought the car about three years ago. Most of the time she is fine, but then from time to time the electrics start to go screwy. The blower dips off and on, so does the radio. Then at night the lights will dip briefly, or sometimes will dip with the indicators. It seems to do it a little and gradually gets more.

The first time this happened I had the battery and alternator checked, ok. I put it down to a bad earth or conection and cleaned the battery terminals. All came good for a while. Then a few weeks later it happened again, same. And this has been happening on and off for three years.

Although the auxiliary electrics go funny the car has (so far) never let me down and drives fine.

I have also realised that the connections are not dirty or corroded as the last few times it has happened all I do is take off the negative terminal for a minute and put it back on and the car comes good again for a while.

Has anyone had the same or similar problem? If so what could it be?

TIA

Chris.

[Jim.]

What make and model is the vehicle?

[Chopperlamb]

2003 V6 Camry Altise

[Jim.]

Chris,

I would start by checking all the individual earth plugs and lugs etc. They will be shown on the circuit diagrams. If one or more has come loose, it could be creating earth loops and causing problems.

Also, it might be good to check the OBD (on board diagnostics). I suppose this is a OBD2 vehicle, which means you would need a OBD2 code reader.

I'm not saying the problem is an open earth, but that is where I would begin testing.

Darn frustrating, intermittent faults like you have!

[OldMech]

I know the problem well. But not the common answer! You have done well with what you have done. I'm going through the same experience. That strange aspect of removing the battery earth and putting it back again clearing the trouble - temporarily! At the moment I'm suspecting a 'bad' connection 'somewhere' between the block and the battery earth. Next I will try a new earth braid or heavy lead from a 1000% (!!) good connection to/on the block, straight to the battery negative pole. I've even run one side of my jumper lead for that - and it worked perfectly. There is a faint echo way, way back on the first Holdens. Yes I was there! Good luck.

Edited January 17, 2015 by OldMech

[Jim.]

Old Mech,

Is that your vehicle in the avatar picture? I guess it would be an OB2 (On Board Diagnostics 2) generation, meaning the computer codes (it if has a computer) would be easier to read without a code reader.

Have you checked them?

[trentmeyer23]

Old Mech,

Is that your vehicle in the avatar picture? I guess it would be an OB2 (On Board Diagnostics 2) generation, meaning the computer codes (it if has a computer) would be easier to read without a code reader.

Have you checked them?

That is an SV21 or SV22(possibly VZV21) so it would be OBD1 not OBD2.

[OldMech]

As per my very long history in electronic repair occupation (before B/W TV, RAAF 50's Radar.) the snag with this type of fault is that of its intermittent nature. Electronics are infuriating that way. Screamingly so. Thanks for the info anyway.

[Jim.]

Thanks for the correction Trent.

OldMechanic.

Yes I know the frustration of chasing intermittent electronic faults.

I can't help but suspect one or more of the earth strap joiner clips. I think I would clean and service each of them with CRC or WD40. Do you have access to the wiring diagrams?

[OldMech]

".... one or more of the earth strap joiner clips" .... Jim where normally are they to be found in general. I have been wondering very strongly exactly along those lines.

Laurie.

[Jim.]

There will be two or more on the Engine block to start with. I will have a look on the wiring diagrams for that model later on and see if they are listed. On my 5SFE engine, there is one black strap with a plug and socket that runs over the engine stabiliser mount behind the alternator for example. I would check both ends for any corrosion and also disconnect the plug and sockets and give a shot of cleaner such as WD40 etc. before connecting again.

Do you have access to wiring diagrams for that model?

My electronic service manual(s) are listed by year model. So post your model details here, and I'll have a look at the diagrams I have to see what I can find. With some perserverance, we might be able to find them all and then you could service them all.

Edited January 19, 2015 by Jim.

[Chopperlamb]

Hi guys,

I have just seen your posts and many thanks for the input.

At first I would totally agree as to it being a bad earth or bad connection. But the strange thing is that it runs for a few weeks fine, then it will blip by either the radio will flick off for a second, or fan will dip. Then might not do it for a bit. Then gradually over days it gets more frequent until it gets like a disco, lights dip etc. Then all I do is diconnect the negative on the battery without cleaning or anything, put back on and all is good again for a few weeks. If bad connection I would think more irregular. This is intermittent but with a kind of pattern.

The Sparky at work says it could be a "voltage regulator"???? Can anyone enlighten me?

Cheers.

Chris.

[Jim.]

Chris,

The only voltage regulator in the vehicle that I am aware of is the alternator voltage regulator. Everything else is 12 volt. Unless of course, the computer has a 5 volt regulator in it. However, if that was the case and it was faulty, it would go open or short circuit and blow the computer or shut it down. Either way, the car would not run.

Your last post would have me checking the chassis earths under the dashboard. They are not too hard to dismantle, at least my generation 2 Camry isn't.

I'm currently wrecking one, so will have a look under the dash of that one to see if there is anything I can possibly lead you to.

I've just had a look at the engine bay earth straps on mine. If there was a small brake fluid leak while filling some time long ago, it could cause corrosion around the bolt that fastens the two black straps I mentioned (or any of them). I would undo them, rough sand up the body panel to bare metal and the lug and bolt; replace, tighten and then paint for future protection.

The wiring diagrams don't show these earth straps, which on reflection, makes sense. They don't connect any discrete components to any others, so to speak.

Don't give up!

[Jim.]

Where have you gone Chris?

[OldMech]

Hi guys,

I have just seen your posts and many thanks for the input.

At first I would totally agree as to it being a bad earth or bad connection. But the strange thing is that it runs for a few weeks fine, then it will blip by either the radio will flick off for a second, or fan will dip. Then might not do it for a bit. Then gradually over days it gets more frequent until it gets like a disco, lights dip etc. Then all I do is diconnect the negative on the battery without cleaning or anything, put back on and all is good again for a few weeks. If bad connection I would think more irregular. This is intermittent but with a kind of pattern.

The Sparky at work says it could be a "voltage regulator"???? Can anyone enlighten me?

Cheers.

Chris.

Back again with no real answer. The 'voltage regulator' is built in to the alternator as far as I know and the alternator would need to be replaced to even just try to see if the fault goes away.

http://www.madelectrical.com/electricaltech/howitworks.shtml.

The earth lead on the battery negative terminal (post) . is a clamp type on my vehicle which builds up 'verdi-gri' - corrosion inside and when we remove that terminal it disturbs that connection. All OK when I put it back on.The peculiar thing about my similar problem is that is occurs more after the car has been parked on a side slope!! Passenger side 'down-hill'! Weird. Also it's worse if the battery is down a bit. The intermittent aspect? A recharge top-up every now and then improves things. Good luck. Laurie.

Edited January 26, 2015 by OldMech

[OldMech]

Hi guys,

I have just seen your posts and many thanks for the input.

At first I would totally agree as to it being a bad earth or bad connection. But the strange thing is that it runs for a few weeks fine, then it will blip by either the radio will flick off for a second, or fan will dip. Then might not do it for a bit. Then gradually over days it gets more frequent until it gets like a disco, lights dip etc. Then all I do is diconnect the negative on the battery without cleaning or anything, put back on and all is good again for a few weeks. If bad connection I would think more irregular. This is intermittent but with a kind of pattern.

The Sparky at work says it could be a "voltage regulator"???? Can anyone enlighten me?

Cheers.

Chris.

Back again with no real answer. The 'voltage regulator' is built in to the alternator as far as I know and the alternator would need to be replaced to even just try to see if the fault goes away.

http://www.madelectrical.com/electricaltech/howitworks.shtml.

The earth lead on the battery negative terminal (post) . is a clamp type on my vehicle which builds up 'verdi-gri' - corrosion inside, around the wire itself, and when we remove that terminal it disturbs that connection. All OK when I put it back on.The peculiar thing about my similar problem is that is occurs more after the car has been parked on a side slope!! Passenger side 'down-hill'! Weird. Also it's worse if the battery is down a bit. The intermittent aspect? A recharge top-up every now and then improves things. Good luck. Laurie.

Also: http://en.wikipedia.org/wiki/Voltage_regulator. L.

Edited January 26, 2015 by OldMech

[Chopperlamb]

Where have you gone Chris?

Hi Guys,

I have not been online for a week, many thanks for your input.

[07Prodigy]

How'd you go?

Because it's the same problem with everything that has a fault, I would agree it is more than likely a faulty earth.

It's possible it could be a faulty positive cable but I don't think it's likely.

[OldMech]

Yes, I've just discovered on mine that the direct negative cable to the engine block - very, very important - had come adrift from the battery negative clamp. Another one in that clamp goes to the 'vehicle body earth' bolt - but that one to the block is the MOST important one.

[Chopperlamb]

Yes, I've just discovered on mine that the direct negative cable to the engine block - very, very important - had come adrift from the battery negative clamp. Another one in that clamp goes to the 'vehicle body earth' bolt - but that one to the block is the MOST important one.

Hi Guys,

Well she is playing up again. One thing I have noticed is that the console clock/computer sometimes is brightly illuminated and sometimes is dim, I do wonder if this is something to do with the cause of the other faults. The other night we were driving back from a concert at night and all the auxileries (lights, blower, radio) were flicking on and off, more and more frequent than before. The radio even reset itself and I am sure for the first time it affected the running of the car as the speedo and rev counter blipped. The following morning I pulled off the battery and also cleaned the earth connection to the block and to the body as OldMech mentions. Set off for a trial run and all seemed fine, also clock brightly illuminated. Then halfway through the run noticed that the clock was so dim it was hardly visable, but everything else seems fine, radio, lights, blower etc. She has now ran for three days ok, yet the clock is still dim? This is so strange.

[trentmeyer23]

Is the clock dim with lights on?

[OldMech]

I think our replies have got lost in the email system.

i'll just wait awhile, and check on my answer meantime.

Clock dull with headlights on, bright with them off - normal daytime driving, except if you want to be extra safe!

[OldMech]

Yes dim with the headlights on.

'Clock dull with headlights on, bright with them off - normal daytime driving, except if you want to be extra safe and have your headlights on in daytime!'

Ive been replying on the notification email facility. And it's been 'bouncing' there!

Sorry.

[Chopperlamb]

Hi, makes no difference to lights on or off. Can start of very dim, hardly visable. Next thing you look and they it is bright. Day or night, lights on or off. four days now since the last time I cleaned the earth connections. Everything else (blower, radio, lights etc.) seem ok for now but the clock keeps dipping in and out.

[OldMech]

Just leave it and see what happens. It may be 'just oine of those things'.

There are so many connection plugs and sockets under the dash it could take years to find the 'bad' one.

If its annoying cover it up with tape. I have a $2 shop one sitting in front of my speedo as a 'spare'..

The main probems seem to be behaving.

Things come and go.

Cheers. Laurie.