Start by figuring out what the cause of the fault it, then go from there. Check for power at the lights. If you don't have that, check for continuity in the switch. If you don't have that, replace the switch.
One bulb burned out, replace it. All bulbs not working, check the dash illumination switch to see if it is turned off, if not check the fuses.
were is the iac locate on a 1999 mercury mystique
According to the 1998 Mercury Mystique Owner Guide : ( 61.5 litres / 16.2 U.S. gallons )
common problem with 1998 mystique check engine light on
yes
On a 1998 Mercury Mystique : To the left of your tachometer is the seatbelt reminder light and Under your fuel gauge is the airbag readiness light ( if the light stays on or flashes take your vehicle in to have the airbag ( Supplemental Restraint System , SRS ) system checked out / repaired
No , coil pack
HAVE AN AUTO STORE OR SHOP HOOK UP THE OBD2 SCANNER TO SEE WHAT CODES ARE
Yes, but if it stays on you should plan to take it in soon to have the engine checked. That is why the light is there.
That should be OBD 2
Replacing ERG Valves in a 1998 Mercury Mystique is fairly hard because it requires great precision to avoid blocking the EGR passage.
I don't think so.
A 1998 Mercury Mystique with the 4-cylinder 2.0 DOHC appears to have a non-interference engine. Therefore, if the timing belt breaks, there should be no damage to the valves/pistons.