Top 20 1998 Mercury Grand Marquis Questions & Answers

That's not the way it works. You purchase a Bypass Pulley and fit it where the compressor was. Same belt routing and length. https://www.google.com/search?q=1998+Mercury+Grand+Marquis+bypass+pulley ..

Going to have to start by checking for fault codes.

Yes replace your spark plugs first check your wires aswell

Is it VERY quiet at the tail pipe?Could be the converter on the exhaust is plugged up.

Yes, the balancer may be coming apart. Check the rubber between the two pieces to see if it has shifted. Also see if the belt is aligned with all the pulleys

first suggestion is broken timing belt second is failed crank shaft position sensor third is failed cam shaft position sensor forth is failed ignition control module fifth is faulty ECM or power fuses to the ignition, ecm

Yes, it can be tightened from the back.

If you think the problem is the security system. This is for programming with no keys. Use a scan tool to verify that the numkeys pid value is less than 8. Use a scan tool to verify that the sparekey pid value is enable or yes. Insert either the remaing key or a new cut key and turn to run. Use the sacan tool to navigate to pats system and then choose security access. The scan will count to 10 minutes before the model will allow you in, once in, choose ignition key codes erase. Did connect scan tool and turn key off. Inset key and turn to run for 3 seconds, then turn the key off and remove. Insert second second key and turn to run for three seconds, then turn key to off and remove.

https://www.youtube.com/watch?v=JOKTCDiFU-Y Hope this helps

Some possibilities, battery--battery connections--generator--generator wiring-- too much parasitic drain with everything off. Here is charging system diagram. I didn't look for mega fuse, I will if you want it. In the diagram, you can see applicable fuses and fusible links. If battery is down get it charged up, can't do any testing if battery is down. With a charged battery, everything thing off, use digital multimeter across battery posts, the generic spec for a full charge is around 12.6 volts. Then start vehicle, take second reading across battery posts, the second reading should be higher than the first if charging system is working.

Assume you mean drains of power not fluid. Does battery light show on dash with engine running. Make sure that the alternator drive belt is correctly tensioned (longest side betwen pullys move 1/2" up/down). If it takes a few days to loose charge temp fix is to use a solar battery charger that can charge battery when car is parked. Hope this helps.

Some vehicles may require taking the steering column out, but start by taking covers under the dash off just about anything that you can visualize that has a screw, be sure to unhook the battery cables just so you don't set off anything,unhook airbags when you get to them,take some pictures if you have a phone it will help you to remember, but i would. Only. Take off what is needed to get the job done

Inside the gas tank

Hi Carnell,here's a link to your cts. Where is the coolant temp sensor located on 1998 mercury grand marquis LS...

shouldbe in glovebox

Check cruise control cable under hood is tight enough to pull throttle arm. Check brake pedal . see if wires to cruise control are still attached to switch on brake pedal. Check magnets are still on drive shaft if rear wheel drive. Check hall effect transducer is still in place to dedect magnets spinning on drive shaft. Check Vacuum tubing is ok on cruise control it pulls the cable in and out . Check if ignition sensing that wire is connected that senses ignition pulses ( front wheel Drive) Check if a speed sender device is used on speedo cable to create pulse (front wheel drive ) sometimes used to sense speed on some cruise controls. Check wiring around plugs and sockets under bonnet.

bad voltage regulator

This is usually straight forward but I understand there is a bolt on the drivers side rear kind of hidden between the Firewall and engine. Also if you have an antifreeze leak on the front passengers side it is a common defect. At one time there was a Warranty for this defect.

It might be located in the glove box.