Hello all,

I'm new to this forum and hope I can contribute with solutions more than problems in the future. At the moment I have a `87 Aerostar Eddie Bauer 3.0L-V6 with the digital dash, and one issue that has led to many of my hairs being pulled from my head.....

The digital dash goes out as soon as you turn on the parking lights or headlights. There is no illumination to be seen anywhere, but when the headlight switch is turned to OFF it's lighted perfectly for the daytime. I have tried another dash, dimmer, and headlight switch to no avail. I did some diagram digging and noticed a DAY/NIGHT ILLUMINATION RELAY somewhere in the circuit. Ford discontinued them some time ago but I did find a listing at Napa for $85. However, it's mine (with no returns) after the purchase because it's a special order part so I need to know if there's anything else it could be.....<O
<O

I've had this van for over three years now and have not used it on a regular basis because of this issue. I'd really like to start driving it because I put a TON of work into it shortly after I got it.....

<O


Any help would be much appreciated...!!!


~Justin

 

I'm not sure where that relay is, but it's probably under the dash some where. If you can locate it, you can try bypassing it.

It sounds like you've checked all the parts that are involved. Did you check the pins on the connectors on the headlight switch or dimmer?

 

on '93 Aero digi dash

Top LH side of I/P, near instrument cluster
called Switch Module

connects direct path 4 leads to the digital instrument cluster

is yours a Canadian model with the daytime AutoLamps?

 

Please see this thread, where I put a picture of where the Day/Night Illumination Relay is located.

 

That is exactly what I went through with the Ford dealer...!!! Except I didn't have the number because NOBODY could tell me where it was located or give me a picture, which is why I called NAPA.....

I really appreciate the help and should have searched for this topic first. It's ironic that I've had this van for three years and finally posted this question exactly one month after the one that you linked to was posted. As soon as the temperature gets above -10 I will pull it out. If need be I will just pay what NAPA wants but would prefer to spend less.....

asavage, how long ago did you find the one at FORD dealer and do you remember how much they wanted...???



~Justin

 

Welcome!

 

It was about four years ago that I replaced mine (after living with intermittant nighttime dropouts). I think it was under $30. Once I had the number off the relay, the parts guy found it immediately. It apparently is used for other functions on several vehicles (?).

I'm sure I kept the part No., but I gave all the receipts to the new van's owner last year.

[later]
I just asked her to check the receipts and check for it. May be a couple of days before I hear back from her.

There is also an outside chance that I actually still have the old (bad) relay in the new relay's box in storage. I'll check tonight on my way home. Usually, I would have tossed all that stuff when I sold the van, but it's possible . . .

I would think it would relatively easy (for me) to wire a generic relay in its place. Because the OEM relay was "easy" to get, I didn't bother back then.

 

Nope, not in storage. I can hope that my old van's new owner can dig out the receipt.

 

That would be great if you could get the number...!!! I would have mine out already but it's brutally cold outside right now, and it's going to be like this for at least a week. I won't be getting it back home (from my storage lot) for at least a few days or so.....


~Justin

 

The owner couldn't find the receipt for the Day/Night Illumination Relay in my stack of receipts, so I drove 200 miles and bought the van back from her . . .

. . . Sorta. I'd sold the Grey '89 XLT to my boss last year, who gave it to his daughter, who just bought a new something-or-other, and the heater core I bought from Ford and installed in 1999 started leaking, so I got the van back (or, I should say, I brought the van back for my boss). I've spent the last couple of days fixing a long list of things that went south in the last year and then were made twice as bad by efforts by someone to "fix" them (mostly wiring cut up and twisted back together). Long story, but relating to this thread . . .

I have been through the receipts twice (there are ten years and $6000 worth) and the relay receipt is just not there.

I am holding the relay right now, and it has nothing of value printed on it:
(click on image for much larger)


I called the same Ford dealer who sold me the relay years ago -- different parts guy -- and told him the story, how hard it was to track down the relay back then, I read him everything on this relay, and he came up with nothing

I tried . . . I really tried.

 

I'm guessing it's a single-pole-double-throw relay. When off, one pair of the large terminals are shorted, when on, another pair are shorted. You can find the common terminal and the normally on/off terminals with an ohmmeter. the two small pins are probably for the coil. Be careful how you test this, as they may have a reverse-biased diode across them; if you apply the voltage in the wrong direction, you can blow the relay.

The Aerostar uses many relays like this. You can probably find a functional replacement in an auto parts store. Better yet, go to a junk yard and try to find the exact replacement. It does not have to be on the DRL circuit.

 

(Doesn't have anything to do with DRLs; it's an Electronic Cluster (digital dash) circuit thing.)

No need to guess, it's shown in the wiring diagram (to which I linked upthread). SPDT, no suppression diode shown.

I know Ford uses this same relay in other places, because it was in-stock when I read the number off of it to the parts guy years ago: he knew the number immediately when he heard it.

But I don't have that number.

A generic Bosch foglight relay that sells for about $5 would do the job -- but then you have to cut the harness and splice the five wires, not trivial from either under or over the dash. Unless you've actually done under-dash wiring repair, you can't know just how frustrating it is to be able to see just what you want to do, but not be able to twist your body so that you can get two hands to the work!

It could also be "fixed" by removing the relay and shorting the Pink/Black and Light Blue/Black wires. The dash would be too bright at night and could not be dimmed, but would still be usable. I wouldn't "fix" it that way, but it's a possible solution.

Me, I'd print that picture of the terminals layout, go to the JY and start pulling relays from another Aero. It is very likely that another Ford relay that is socket-compatible (that is, the relay's socket is the same shape and contains the same terminals layout and size) will work perfectly.



===========================

"Day/Night Illumination Relay". I've glued together some 1989 Electronic Cluster diagrams and put the relay in red in the pics below.

First pic shows the relay as it relates to its feed from the main HL switch. The diagram shows only the relay's coil side, not its outputs.

Second pic shows how it relates to the cluster lamps.

Third pic is a component location pic, showing its approximate location in the dash.

(click on any image for larger)

 

Sorry, I confused this topic with someone else's post about DRL's I'm guessing the DRL systems also use a similar relay.

I second the approach to get a used replacement. Take the old relay with you to find an exact match.

 

The easiest way to ID the relay in your dash is by the wires colors running to it:

• Pink/Black
• Brown
• Black
• Light
• Blue/Black
• Light Blue/Red

On my '89, it can be accessed by merely laying on your back under the dash, it's up in the same rack of relays as others (above the CC module), but doesn't easily come off that relay rack. I had to break off the retaining tab to get it down, and then it was easy to remove.

 

Thanks so much for looking into it asavage, I really do appreciate it...!!!

Our winter has been one to remember so I still haven't had a chance to get the van home to start working on it. As soon as I do I will let you know what I find and how it turns out.....



~Justin