98 Avalon with haunted electrical system?

[i_amuse_her]

Hi. This car is showing its age, but still runs very well. But it is showing some strange symptoms:

1. intermitent flickering of dashboard lights and headlights
2. intermitent re-set of the clock and the radio
3. intermitent display of tracs off and abs lights
4. intermitent total failure of the electrical system (no lights at all, won't turn over, can't get it out of gear). However, if I attach jumpers to the battery terminals and touch the cables to get a spark, everything works -- till the next time.
5. intermitent failure of the AC/heating system. For no apparent reason, in any kind of weather, winter or summer, every so often the outside temperature reading goes blank (or shows 2 dashes) and the climate control unit goes off-line. Ususally, it starts working again the next time you start the car, but sometimes it takes longer, could even be a couple of days. This has been going on for years, maybe five or six times a year. A dealer wanted to replace all the fans (for $900), but that's obviously not the problem.

The battery is new. My mechanic wants to replace the alternator. He says the voltage coming out is fluctuating up and down (don't have exact readings.) Before I spring for one, are there any other possible solutions to these bizarre problems?

[amby]

I am also facing the problem 5 (Outside Temp going blank and all AC/heating/fan stop working)
I have this issue for 2 years now. no real diagnosis as it is very intermittent and never comes up when I go to dealer.

[wonger]

had a customer that had this problem.. the terminal were really corroded and the ground cable was all corroded inside the rubber shield.. might need to check your connections.. and check the power and ground cables.. inside them to see if its corroded behind the rubber shield

[i_amuse_her]

yes, you could be onto something with the ground wire. when it konked out today, i no sooner attached a jumper cable to the ground battery terminal than presto! everything came on. seems to suggest some kind of problem with the ground -- corrosion or loose connection. gonna have it checked out before springing for the new alternator.

any other suggestions? excuse my electronic ignorance, but is there anything like a voltage regulator in the circuit?

as far as the tempermental climate control goes, it seems to be a bit of a problem with this model -- several similar posts are up on the internet and NO solutions offered so far.

thanks for your help.

[amby]

Thanks Wonger for the informative answers.
My battery -ve is very corroded. I don't understand why it gets corroded.
anyway, so u r indicating that this corrosion might be the cause for my ac/heating to go out on a whimsical?

thnx

[wonger]

i amuse her- most of the time.. they are simple fixes.. i would start with the simple and easy stuff 1st.. dont just throw parts at a car to fix something thats not broken.. if your alternator is going bad. your battery light will light up.. and it is cheaper to buy a new alternator than to replace parts inside it.. ( voltage regulator is inside the alternator ) start with replacing your ground cable.. also make sure it is installed in the same place..


the ac problem. i get a few customers with that problem but never could get it to happen when they bring it in.. so i cant do any test till it happens all the time.. unless they wanna leave it for a few days to see if ican get it to happen.. most of the time.. problems like that are hard to fix without it happen all the time.. harder to pinpoint

the ac going on and off.. maybe linked with the corrosion problem.. i would still take care of that 1st.. and if anything else works great and the ac problem keeps coming back.. than it might be something in the ac system that is bad.. but i have not had much time to play with any avalon ac problems yet..

[wonger]

as for as why it gets corroded.. just go pick up some battery protector.. and spray it on anything metal near the battery.. even the tie downs that touch the battery..

most of the time for the corrosion is due to acid leaking out of the battery and tends to eat metal.. = leaking battery = replacing battery

but i could be wrong

[adu1982]

my 2 cents.....

I had the same kinda of type except my cables going from the battery to the car (a 98 concorde however) got so hot that from time to time it melted the battery connectors. Went to dealers and mechanic and every time they said everything is ok, replaced some other stuff nothing. I told both maybe is the cable from the battery but, both places.....oh noo they look great (which they did perfectly on the outside) ...."is just this car gets very hot so they are hot)

After a while getting tired of replacing the melting battery conectors (yes I am talking the metal ones) i changed one of the cables that seemed to get a bit too hot.......and voila.... now 3 years later the corde still runs great......


so just cause they look ok or good on the outside there might be a short in them.....they're pretty cheap to....

[BonzoGonzo]

simple test for a cable:

put a voltmeter across it. one cable to one end and the other cable to the other end. if the cable is resistive, voltage will be dropped across it. if you see voltage, replace it.

[robcam13]

i agree. i sounds exactly like a battery wire issue to me as well.

[adu1982]

my battery issue back then got me into starting to look at fixing my cars myself more and more (i was doing my oil changes but just that).
i remember i paid chrysler 300 for diagnostic&repair back in 02 for my then 00 plymouth neon and then since no actual repair i paid my mechanic another 100$. He told me it was a cable...somewhere....after my corde fix I always wondered if that was the issue in the neon since the problems were somewhat the same.

[VIPTRD]

I've been having this problem too every now and then. Thanks for the info.