First Post

Ok. First of all, I do not know much about cars or trucks, but I learn fast and do my research. I bought a 1998 Ford Expedition XLT from craigslist a couple nights ago. Got a good price and it seems to be working fairly well. Had one owner, no wrecks. I just cant figure out a few things.

1. The 3rd brake light won't work. All other lights work. Since there are 3 bulbs, I am assuming its not the bulbs. I assume it is not a fuse, because the other break lights work fine. Definitely not the break light switch, because it activates the other lights. I know the previous owner used to tow dirt-bikes and such... I am not sure if that is relevant. Is there something that people do when they tow that would disconnect that 3rd light for the trailer? I plan on checking for any loose connections, but most of the wiring looks to be behind the plastic pieces. Any ideas? The cops out here are *EDIT "strict on minor violations" so this nearly renders the car useless until I can fix it. Any ideas or opinions/advice would be appreciated.

2. More of a larger fix, but not that big of a deal: The heat only comes from the back (not defrost vents), and the A/C only comes from the defrost vents. I have both a/c and heat. Something with the vacuum lines? No matter what I set the climate control to, its always heat from the back sides, and A/C from the defrost. If I can't fix this right away, it is not that big of a deal. The heat is strong enough to un-fog the windows even though it comes from the back.

3. It needs a tune-up. Misfires (according to the check engine light) when going uphill. Would a tune-up help this? Again, for my purposes it is not that big of a deal. Any advice will help.

Other than that, there isn't much wrong. For the price I got this thing for, I can afford to put some money into it.

Thanks!

 

1. Assume nothing, check the bulbs.

2. The main vacuum line for the HVAC controls runs under the back of the battery. Corrosion is known to run down and eat through this vacuum line.

3. How many miles on the spark plugs? The plugs are good for 100K miles. The main issue with misfires tends to be the rubber boots for the COPs breaking down over time and allowing spark to jump to the side of the spark plug wells.

Just an FYI, if you plan on changing the spark plugs yourself there is a very strict procedure to follow. Failure to do so tends to result in spark plugs blowing out of the head.

 

Can't help you here. Not a cop but not sure why you classify local PD as "D-bags"?
Hopefully you never need their help.

 

I saw that, wasn't going to comment, but the more I thought about it needs saying - OP that's a dick move.

 

I've run across many a man in blue that would fall under that classification.

 

As have I. Revenue generation and crime scene cleanup. The police used to watch over the people..... Now they are watching the people.

 

Excuse my manners. Maybe a poor choice of words. Maybe "strict on minor violations" would be a better choice. I moved from a large city on the east coast to a small town in the south. Where I am from it is rather rare for a cop to pull you over for something like a 3rd brake light. Here it seems to be far more common, because they don't have much else to look for. Everyone I know, including a cop friend says so. That is all I was saying. Apologize to anyone who was offended.

Thanks for the input, you are all very helpful. I plan on checking it out more today. As far as the sparkplugs, I do not plan to do it myself. Frankly I'm not sure how many miles are on them either, but I am replacing them regardless. I will need to find someone who knows about this special procedure, as I was planning on replacing spark plugs and wiring. Is it in the manual?

Thanks

 

Appreciate the help. You were right about the bulbs. 2 were cracked and one was black. The area seems to have been collecting water. The bulb area was submerged. I plan on sealing this up with silicone once I change the bulbs on Saturday.

What did you mean by the Coil on plug rubber boots? I guess I'll have to look further into that.

 

Do you have the 5.4L engine with one COP per cylinder, or do you have the 4.6L engine that uses coil packs and spark plug wires?

 

Its the 4.6L

 

Only use a thin layer or in the future you won't get in there to change bulbs without cracking the lens.

 

In that case you don't have COPs. Your misfire is the result or worn plugs, bad wires, or weak coil packs. Can't tell you much more than that without being there.

 

Thank you! Huge help. So what I'm gathering is that a full tune up with plug and wire replacement would help. It needs it anyway. The previous owner said so as well. Since the procedure is specific to this engine, I'll be sure to have the right person with experience to do it. Then if still misfiring I'd look into the coils further.

Thanks again!

 

Chances are that the 3rd taillight sockets are no good. You can find a harness by looking around. Don't change sockets - they won't fit into the recess. These are 90 degree, low-profile sockets. I found a good one on eBay when I had the same problem. I also used a special conductive grease on the socket and bulbs; NO OXIDE-A. Good stuff. Be careful not to bridge the connections. As far as the seal goes, I put silicone on both sides. If you don't, (sadly) it will probably leak. I also replaced all the o-rings on the screws that hold it in. Never leaked since. You can also forgo all of this and just buy an LED version. They are out there.

 

Thanks! The sockets work but are a bit finicky. The bulbs come loose, and I find myself needing to check them after every trip. Sometimes a bulb comes loose but not all 3. Due to this, I have not yet sealed it up with silicone. Not sure if there is an electrician's trick to this or not to properly clean out those sockets. I'm considering placing a small amount of teflon tape where the bulb meets the socket. Teflon tape is resistant to higher temps.

With that being said, I saw the LED lights and am considering getting one.

Another problem I'm having is the turn signal switch when making left turns. It just sticks a little, and its something I'd rather not deal with while driving. Think I'll replace the whole switch.