1986 Grand Marquis owners needed... need help

Hi, I recently bought an '86 Grand Marquis. Car is in great shape overall, but the battery drains over night. After some regular troubleshooting, I found a relay in the engine bay that seems to have been messed with and is live all the time.
I would really like to see, how this relay is wired on an untouched car.

 

Is this relay located on the left fender well, in tandem with another? The two I'm thinking of, the EEC power and fuel pump relay, should be inside a plastic cover, and each has a different color, green and brown.

 

Yes exactly... those two plastic covers hold 3 relays and one relay is sitting loosely outside the covers. This single relay has been replaced with a universal 4-pinned work relay. It is this relay that is live all the time.. I can disengage it by taking one of the cables off of the battery. I would really like to know if there are supposed to be 2 relays in each cover? and also I'd like to see how the wires are located in the connector on that single relay...

 

These are on my '89, which are more or less the same from '86-'89 (the wiring was changed in '90 for all Panthers, sedan or wagon). Each of the covers have at least one, then more may be added depending on options installed.

 

Now, I can never remember which is which, I'm attempting to find a component location diagram that tells me. It'll take me a short while. In the meantime, 1) disconnect and charge your battery, 2) do you have a basic 12 volt test light?

 

Okay, like I said, those covers have one each for the fuel injection (EEC power and fuel pump), and the second position is for options installed at the factory. The outside one, I believe that is the horn relay. This is how it should look if you had the factory relay:



That's looking down at an angle.

 

And, if the relay plug is wired such that the center relay terminal is wired, that can be powered by a standard Bosch relay, which is normally not used.
This is a diagram page from the 1988 Ford EVTM (Electrical and vacuum troubleshooting manual), which shows the EEC and fuel pump relay connections are a Ford design, so it has to have a matching Ford or specific aftermarket relay. Now, it can still be a problem if the relay contacts are fused together, so that's why I asked if you have a 12 volt test light. It can be used to show if a circuit is still 'on,' or shorted to power. Charge the battery up, then disconnect the NEG cable, hook the test light between the NEG post and terminal. If there's an energized circuit, the light will be lit up. Once the errant circuit is found, once it's disconnected, the light will go dim or totally go out.

 

yes thats exactly what i'm looking for. I have 2 OE relays in one cover and 1 OE relay in the other and then this aftermarket relay, where one wire is always live. I'll take a couple of pictures tomorrow. I bet I got problems just because of the use of an aftermarket relay alone. Thanks so far!

 

I checked that the generator is actually charging the battery, which it is. The battery is brand new from another vehicle, also in perfect condition. 70A / 760AH.
I couldnt make my multimeter show any flow of current, but this relay is absolutely live with 12 volts all the time. When I disconnnect the NEG terminal, the relay clicks.
Some of the wires in the relay connector dont look right. I'll get back tommorow.

 

For the most part, a Bosch standard relay doesn't generally use the center post, but I've seen Ford and GM relay connectors wired to the center terminal, and when the Bosch relay is installed, it makes a circuit as the center post is energized by the design of the relay. This is the theory I had from the beginning. So, you're using a multimeter, well, it can be used in place of a test light. Disconnect the negative as I've mentioned, set your meter to DC amps (and hopefully, if your meter has a fuse on the amps settings, that it's good), and put one probe on the terminal, one on the post. Don't worry about polarity, the meter will show negative or positive automatically. Anyway, once that's done, normally, the amp meter will show .2-.5A draw on a car without problems, that is normal. Anything over .5 A is not normal. Set it up, read it, then if the amp draw is out of spec, find that relay and unplug it. If it's the draw, the amp reading will drop.

 

Here’s what relays I have… I can’t say which was in which position in the covers.
Can you identify these? Abs possibly identify the issue with this aftermarket relay and the questionable wiring

 

and here is the odd one... as you can see, someone cut and spliced the two thicker wires togehter and stuck them into one terminal. I have only done a quick check with the multimeter and it seems the red wire is the one that is grounded. I'm a GM man, this is my first Fomoco car ever. but eehhh, a red wire that is grounded, does that sound right?

 

Remember that relays in cars are grounded to latch, rather than powered. The PCM is usually what controls the ground leg, so one of two possible problems: either you have a wiring short to ground, whether accidental or was made that way, or your PCM has a fault. I do see my theory did not pan out, that relay should work as a replacement, provided the diagram cast into the plastic case shows it to be normally open (open when de-eneegized).

 

Ahh ofcourse, makes sense with the grounding. The odd relay looks to be completely normal 4 pin relay that is open when not energized. This is why I cant figure out, why the heck it is closed when ignition is off.
Can you identify those 3 relays in my image2.jpeg and point out the one, that I have had replaced with a universal relay? Possibly take a picture of the way the wires are positioned in its connector, so I can compare to mine?
You mentioned a diagram page from a 1988 Ford electrical and vacum troubleshooting manual, but I cant see any links or attached files?

 

I thought there would be a component diagram for the 5.0 EFI left fender, but alas, no. I did take a photo of the electrical diagram page for the two main relays (PCM and FP), but apparently, I didn't post it? So, here it is: