rancej

Sorry if this has been asked and answered but could not find my issue searching thread.

I just bought a 2003 Grand Marquis Ultimate yesterday. All works well and appears to be a great car except the AC Temp. Dring around town under 45mph it's ice cold. On the interstate it does not cool hardly at all. When I take an exit and slow down, it's back to ice cold again. I noticed someone had mentioned a "blend door". Could that be my problem?

Thanks in advance!

chipset

What are your pressures ? You could be under charged.

rancej

Thanks for your reply Chipset. I don't know...I don't have have a way of checking them. I did put one can of R-134a in today thinking maybe it was low. But it works great around town or at speeds under 45mph. Really great and ice cold. In my very limited experience with these types of things I've seen it hot at idle but cold at speed. Never seen it like this one. I tried switching to Normal instead of Max AC but really couldn't tell a difference. I may take it somewhere tomorrow and have it looked at unless someone here has a better idea.

chipset

Send it out. You could be chasing your ass forever and spending money you don't need.
If you don't have the tools and know how to address this you could have a problem and cause real damage. It could ba a completely differant problem. You never know.

rancej

That's what I'll do. I'm fairly handy and have been able to do much with the couple of BMWs I have, much to the credit of the fine people like you on these forums. This is just an odd one. I'll post the results. Thanks again for your efforts Chipset!

rancej

Just got my car back. They replaced the compressor and the lines. Guess what....still doing it. Now i have another problem. Looks like my LCM is on the brink. Hopefully they will replace this for me as well...NAPA has them in stock for $259.

I'll give you guys another update after they fix it. The loaner they gave me was a Lincoln LS so I wasn't suffering TOO much!

no_common_sens

What are the symptoms of your lighting failures? If it's related to the rear brake lights, it could also be a break in a wire that runs over the top of the steering column going to the LCM. If it IS your LCM, fixing your original is a possibility. I'm looking into repairing LCM's myself. My understanding is that the relays go bad in the original LCM's. It turns out that you can buy new ones for $3.38 a piece at mouser.com. The part number for the relay is EQ1-11111S. The LCM I'm working on at the moment is for an 05 so the relay might have changed from year to year. I already know for certain that the 03-04 LCM isn't the same as an 05 LCM. What makes them different is beyond me. You need to be reasonably proficient with soldering on circuit boards to replace these relays. I have the soldering skills and a fleet full of bad LCM's waiting to happen so I'm going to attempt the repairs. I'll try and get back to let you know the results of my repair once parts do come in.

no_common_sens

The relay replacement was a success! Mouser.com was insanely fast and we'll be saving a ton of money from here on in.