1989 Mercury Grand Marquis OBD connector location

[lithdoc]

Hello,

I recently bought my 89 grand marquis, and I have issues with heating inside. I have a feeling the thermostat has been removed from my car, but I would like to check the engine temps with OBD first before tearing it apart. The issue is that I cannot find it. Actron manual points to left fender skirt, clymer manual points to passenger side fender by strut cover, but I just cannot find it. Please advise.

Thanks in advance!

[lithdoc]

Well, after readings this forum for a little bit more, it seems that the issues with heating are rather common in this car, and they're likely to be caused by vacuum issues... However, I still would love to know where the actual interface connector is. Thanks.

[GM_Guy]

The connector you seek is located near the front left corner of the engine bay by the relay pack.

Alex.

[87gtVIC]

It is on the drivers side inner fender up near the relays mounted on the fender just behind the washer fluid/coolant reservoir.

Two plugs if memory serves me correct. One is a funky looking one with a couple of wires and the other is a single plug with wire.

Check out this thread and posts by 91waggin http://www.grandmarq.net/vb/showthread.php?t=33147

EDIT: I was treed.

[lithdoc]

Wow, you guys rock, found it right away with your help! I wonder what reasoning ford had for locating those under the hood, and not in the cabin.

Anyway, great disappointment. Unlike GM actron OBD1 interface, this won't display any engine data, just run the codes. So, no information on engine temps (unless there is another mode I'm not familiar with) and I also found 3 codes - 10, 20, 34. Something with cylinders 1 and 2, then some EGV (?) voltage too high. Any ideas? Thanks again.

[gadget73]

nope, no engine data.

10 is either a spacer code or cylinder 1 failed the balance test, if you put it in balance test mode
20 is a cylinder balance test code
34 is egr related, possibly crap in the egr valve or a bad sensor on the egr valve

[lithdoc]

What are the balance test codes? Is it anything to worry about?

[GM_Guy]

Balance test is a basic compression comparison between cylinders.

Why underhood? Unlike OBDII, there is not much data to be gotten from the data stream.

Alex.

[gadget73]

I wouldn't pay much attention to those unless you have a problem. bad spark plugs can trip those, and they even tell you its meaningless unless you get the same codes several times.

there are several tests, the key on, engine running, key on engine off, and the cylinder balance test. Balance test is triggered by goosing the throttle after the KOER codes are retrieved. You kinda have to know what test you're doing to determine what the code actually means. Sometimes it varies a little depending on the test.