My elderly aunt has a '96 Toyota Tercel which is still running and in reasonably good shape. However, the A/C switch on her dash has broken (two position button switch). She had something jammed in there for a while, which held the switch in the ON position, but that no longer works. The air blows cold when you can get the switch into the on position, but that’s not working now and the temperature is in the 90s.
My plan is to pull the panel off the dash, remove the switch and just put an old-fashioned toggle switch in there so she can switch it on and off.
My question…do I just get a cheap toggle switch or do I need something really heavy duty. Amperage ratings would help. I assume the switch is low current and controls a relay, but I don’t want to take the chance of putting in a low amperage switch that’s just going to quit working after a week.
The best solution is to find the corresponding fuse in the fuse panel and then match the switch to the rating of that fuse. That way, you’ll guarantee the switch won’t be underrated. You may also find when you get the old switch assembly out of the dash that it has rating information imprinted on or molded into it. Also, check the wiring of the original switch before purchasing your replacement; it could be a multipole switch, which means it simultaneously switches more than one circuit.
Best wild ass guess is that it is a single pole switch.
The switch may carry the A/C clutch current (~10 amps) or it may not.
Get a switch rated for 15 amps and you should be good to go.
Look in your area for what we call a “you pull it” yard. If you have the tools and skills, a replacement switch would cost no more than $10 around here. Match your model and year, and ask the folks like Rick or Gary T what models/years will interchange, and you should be good to go.
The wiring diagram shows that the switch itself has a resistor, a transistor, and two diodes inside it. It shows three wires to the switch, with two of them connected to the A/C amplifier.
I strongly recommend getting an exact replacement switch, new or used.
Thanks for the vote of confidence, but I don’t have a clue. I just order from a parts store, dealer, or salvage yard and trust them to provide the right thing, so I have no need for interchange information. It’s the salvage yards that use interchange manuals.
Gary T, if the switch is that complicated, I’ll probably just see about ordering it from a dealer. Is it possible the electronics inside the switch are because of the light that indicates the A/C is on? I was figuring there’d be a separate hot and ground that powers the light, but if there’s just two leads, maybe the light is powered by the current running through the line?
Danceswithcats, we don’t have a “you pull it” here yet…just junkyards. Pull-A-Part is getting ready to open one nearby, but they’re still buying cars and not selling anything yet.
FYI Balthisar, around here, junkyards aren’t allowed to let customers in…you have to get them to pull the part and pay them the labor to find it and pull it for you. They tend to turn their noses up at parts that are only worth about 50 cents used. They want to pull a transmission, not an A/C switch. A “you pull it” is organized and doesn’t have cars stacked 10 high, so there’s not as much of a liability issue, and if you want to go rooting around for radio knobs, or fuzzy dice, they’re more than happy to let you do so.
Unfortunately, the closest “you pull it” is in Gulfport, MS, which is about 60 miles away, so the cost of gas would be greater than what the dealer would probably charge for the part brand new.
It may be it’s just for the light, though it seems a rather complicated way to do it. Here’s what I see:
A white/blue wire which should show 12 volts when the ignition and blower are switched on.
A white wire which should pass the 12 volt signal to the A/C amp when the A/C switch is switched on.
A green/yellow wire, connected inside the switch to the white wire, which then goes through a light-emitting diode, a regular diode, a transistor, and a resistor, and then goes to the A/C amp. I suspect the A/C amp provides the ground for the light-emitting diode through this wire. What’s not clear to me is whether this wire is also providing some signal function to the amp.
On review, it appears that putting a simple toggle switch between the white/blue and white wires will provide the basic switching function. If the switch connector is left plugged into the A/C switch, then the green/yellow wire would still connect to the amp. As to how/whether everything would work if the switch connector were unplugged, I don’t know.
So, unplug the A/C switch and replace it with a toggle between the white/blue and white wires, and it may work. Alternatively, leave the A/C switch plugged in and tap into the white/blue and white wires with the toggle as an additional switch, and the function should duplicate the original set-up.
Here’s a twist…There seems to be some function in the light on the switch that makes the light blink when the A/C belt is slipping. Could it be possible that the extra wire leading to the A/C amp is to make the light blink? If so, I’d guess that it wouldn’t hurt anything to have that wire completely disconnected. It would just eliminate the warning function of the blinking light.
Got you. I also should have mentioned that I think current yellow pages also call junkyards (etc.) “Auto Salvage” and/or “Auto Recycling.” In my parts, all of the junk yards let you pull parts yourself. The places where the cars are stacked 10 high have already been picked through, and those are just scrap metal yards. Our junk yards also have large sized facilities where it may not even be necessary to pull it yourself. All of the common components will already have been warehoused and binned.
As it turns out, there is a place near my house that lets you pull the parts, so I went there early this morning, but they didn’t have anything I could use. They said I’d have to buy the whole panel for $40.00, which isn’t too bad. Unfortunately, only the '95 and '96 Tercels have that particular panel, so I couldn’t find anything useful.
I know where all the salvage yards are because I play around with old cars, but most of them don’t have cars old enough to be of any use to me. This is the newest car I’ve ever tried to find a part for.
Okay, new update. The car is a '95, not a '96, and therefore has a completely different set of controls.
The A/C switch slides right out and there’s 4 connectors on it. Behind the panel, there’s 4 wires attached to the clip. Three of the wires matched the diagram I had, so I tried jumping the White and White/Blue wires and nothing happened.
I then took the switch apart, and there’s more than just a couple of diodes and a resistor. There’s a whole circuit board on there with an adjustable pot. No clue what was beyond that.
I put it all back together and it’s the same as before. If you play with the switch, the LED will light up briefly and you can hear the relay behind the glove compartment click, but it won’t stay on.
I’m going to trek out to Gulfport this weekend and see if I can just pull a switch out of another car and see if that works.