I have a 1998 Toyota Camry LE 4 Cylinder. and at night when i turn on the headlights and the heat the lights dim down also does it if i roll the window up or down but if i dont run the heat/defrosters or mess with the windows its fine.When they dim the dash lights dim down as well then once i push the gas they brighten up I let off and it dims down same with the heat. The heat dims down sometimes just not all the time. I took it to Autozone and they tested the battery and the battery had a dead cell so I replaced the battery or should i say they installed it because i have no clue about cars. During that time the alternator was also checked and its fine. So im clueless and hoping this isnt something too serious. theres no check engine light or anything like that on. So im asking on here what do ya think it is or could be?

 

Typically it is either the battery or alternator. Could also be the battery cables or wiring between the alternator and battery.

What RPM does the engine idle at, should be around 800 RPM.

Surprised there is no improvement after the battery replacement as a dead cell would cause this type of problems plus starting issues.

Does the car have a high output stereo?

The alternator puts out less current at idle the at say 1500 RPM. If there is too much currant load at idle from the heater, lights, etc the battery needs to make up the difference. Changing the battery should have improved the situation.

If the charging system is not working at all (not the case here) the alternator light will come on, not the check engine light.

 

Not seeing any lights whatsoever, and it does have a Pioneer high output stereo and it dont cut down at all the least little bit. The battery cables had corrosion on them but the dude at autozone that changed the battery got that off. it idles between the 0 and the 1 now when its cold it idles a lil above the 1 then when it warms up it goes down. the stereo is a Pioneer DEH-1400 45 Watts X4 Channels. hooked to factory speakers no fancy subs or amps.

 

The alt may not be putting out the current it should be at engine idle but be OK at higher RPM.

It is normal for the engine RPM to drop after warmed up.

You stereo does not pull that many amps.

Still might be a bad electrical cable, ground cable, etc.

Do all the other electrical items also dim (slow down) at engine idle such as the blower
speed slowing down, wipers slowing, etc? Or just the lights are dimming?

 

If ur referring to the blower speed as the heat yes it does slow down when the lights are on but when the gas pedal is pressed it speeds back up this only happens with the lights on. Only other thing that dims the lights for a second is the windows being rolled down they also cut down the heat if it is on. but like i said the lights dim and i push the gas they brighten back up their not doing it so much now but they still do it but if the heat is not run at all they do not dim whatsoever. I wouldnt think it would be a fuse because if it was that it wouldnt work at all. Electrical cable what u mean by that? the alternator was checked inside the car at autozone now i know nothing about taking it out and getting it checked but they said it could give a different reading outside of the car and when they tested it i had lights stereo and heat on.. so im not sure.i appreciate the replies in helping me figure this out. if this is nothign really to worry about then I wont but if it is id like to fix it. it still starts up the first time no issue there even in the cold cold temps we've been having lately the battery also has 600 cca cold cranking amps its a duralast. the battery in it was corroded and the guy at autozone said it didnt fit this car. This car is my mothers but i drive it most of the time she hasnt had a car in years so im trying to get this one in top shape for her she just bought it she likes toyotas we've heard great things she used to have a celica 85 to be exact we liked it we like this one just want it going right i appreciate the help.. thanks

 

If the problem does not bother you or your Mother then would not worry about it.

By wiring I mean some times the cable between the alternator can be damaged or the ends corrode, etc resulting in poor contact.

The same is true of the negative ground cable (attaches to the chassis) and the cable that runs from the engine block to the chassis.

You saw the corrosion on the battery terminals, this can also happen else where but not be as evident.

It is normal for the lights, etc to pick up as the RPM goes up because the alternator is now putting out more current.

Suggest you just keep an eye on things, that the situation does not get worse or the engine become slow to turn over when starting.

If you check the dash light icons there will be one for the charging system. Not sure exactly what it looks like but with the ign key on all icon lights should be on. You should then be able to figure it out, might have the words ALT, charge or a lightening bolt symbol.

The owners manual will have this info.

If this light comes on when the engine is running it means the alternator is no longer working and the car is running off the battery. Sooner or later the battery will become dead thus head home or to a repair station.

 

Alright I appreciate the responses it doesnt really bother me i was just worried. The only light i see relative to that is a battery light but it doesnt stay on. Yes i will continue to monitor this and see what happens. theres a light on the dash its like a square and it shows what gear ur in drive park etc. and it dims during the day when the window is rolled down and i noticed that it does it without the heat on and the clock dims down and the stereo when the window is rolled up or down. the battery has free replacement it still starts up with ease so like ya said i wont worry bout it it just irritated me. anyway i appreciate the response thanks for ur time.. have a good night. thanks again!

 

I've always had the same problem with my 98 camry, I've had it for about 6 years now. Lights dim when I use the power windows, and I think I've replaced the battery 3 times now since I've had the car because it seems to love to kill them. The electrical systems on these cars are crazy

 

It's your alternator. It's not generating enough current to power all the electrical drains on the battery. That's why everything slows or dims when you let off the gas.

Don't pay for a battery when you don't need one. Buy a used alternator (with a warranty of some kind and have them test it) at a salvage yard for $35 and have a good mechanic install it. This should correct your problem

Camry's/Toyota's are notorious for having electrical issues after some time. I just had my 92's alternator replaced because of the same issues you described. Plus my factory radio had a short and was drawing power from the battery when it was on and off. But my battery didn't need to be replaced.