Dimmer Switch Replacement

[yogi_123rd]

I've got a 93 GT. Low beams work OK, but when high beams are selected, no lights. I assume it's not a relay problem because low beams work.

Is there a relay involved for high beams?
How/what is involved in changing a dimmer switch on a 93 GT.

Thanks in advance for any help.

[nialusa]

This may seem like a daft question but have you checked the bulbs?

[yogi_123rd]

Both bulbs new. Only high beam out.

[nialusa]

OK, try the fuses next, then your earthing points for the high beam, relays etc, Replacing the High beam controls will probably be very expensive. Is it a switch on the dash or on the control stalks that come off of your steering columb?

[yogi_123rd]

You say: "OK, try the fuses next, then your earthing points for the high beam, relays etc,"

What is an "earthing points"? Some sort of relay?
The fuses (I could find) have been checked. I could understand if it's a relay involved. The relay box in the engine compartment is sometimes flops around because it's not bolted down.

The dimmer switch is column mounted and looks like to replace would have to remove the steering wheel. UGH. I am kinda hoping that there's a relay or fuse involved (and where do I find it) that controls the high beam.

[nialusa]

Car Electrics the basics - You know of course that for electricity to feed a given device, be it a light bulb or motor etc that the deivce must be within a circuit attached to both the positive (+) and negative (-) ends of the battery. Cars are the same, anything electrical on the car must be so. The positive side will be fed through a wire which will go to a relay which is fed with extra power, or for less powerful items will run directly from the control switch to whatever its controling. To save on the amount of wire that is used, the "negative wire" is the entire car body so everything electrical at some point is connected to the body of the car. These are known as earthing points,which is actually an incorrect term, as its not an earth at all its the negative side of the battery.

For your high beams this earthing point is probably running from the relay, you just have to find the correct one, I cant help you there as I dont have the same generation of Celica as you or i would be able to check myself. (earthing wires are prone to snaping)

Relays are usualy clearly marked, look in the cover of the relay box and there should be a diagram with each relay marked as to its task, and do yourself a favour and bolt down your relay housing box as it will damage your relays realy quickly if lfet to rattle about your engine bay. Check your fuse holder in your dash as there are often some relays in there too.

If you do have to remove your steering wheel, if you dont have an air bag its not a big deal you`ll just need somthing like a 28 or 32mm socket to remove the retaining nut. A screwdriver to remove the steering column housing and a new control arm which will probably be held on by a couple of bolts or screws, an easy job realy, if you have an airbag then your stuck or at least I am cause I have never had to deal with a car with an air bag before.