Box Interchangeability

[packman]

Does anybody know if the front fascia (headlights, core support, and grill panel) and the rear fascia (tail light panel) from an '89 MGM will fit a '91 MGM? A friend of mine got a '91 box MGM and he said the headlight buckets are rusted and from the looks of it, the tail light lenses are busted. I just went to the junkyard over the weekend and they just got two '89 MGMs that appear to be straight. I will see what's involved with changing those parts out. There is rust on the fenders too; so down the road, I may have to change them out as well.

Packman

[mcninetyone]

It is very tempting to think these two front ends would be plug and play, and they probably are. I just did a 03 front end on an 02, which was said to be plug and play. And to a large point they were, but it was not as easy as that. Besides some wiring which I knew was different, I found other things that were not plug and play at all. The core supports are different so the 03 support won't work at all and the 02 support has to be slightly modified. The fenders were a small problem but nothing that couldn't be done, and the front bumpers were different too. My guess is that between an 89 and 91 the front ends the differences, if any, will not be a big problem. And that you can swap the parts with little or no trouble.

[sly]

88-91 will interchange with no issues.

[gadget73]

should be fine. Just keep the harness from the 89 so you don't have to mess with the plugs possibly being different.

[Tiggie]

Can't speak for the Merc, but 1988 and 1989-91 header panels have minor differences for a Ford. http://www.grandmarq.net/vb/showthre...l=1#post506082

[VicCrownVic]

My '89 MGM had a header panel from a '91 MGM after my dad wrecked the original thanks to a deer. Then I wrecked that one and replaced it with the header panel from my Mom's old '88 MGM. No differences as far as the header panel goes.
I don't recall any differences with any of the other stuff mentioned.
Although as Gadget mentioned I think there were some changes to some of the electrical harness connectors. I don't recall any specifics but I think where the headlight harness plugs in might be different.

[packman]

Thanks all of you for the quick answers. I will take a good look at the headlight plugs. I might see if I can upgrade to relays while I got things apart; that depends if he wants to spend the extra $35.

[VicCrownVic]

The plugs at the bulbs are the same, it's further into the engine bay on the driver side inner fender area where I think there is a difference. Wiring differences are easy enough to deal with if you have to though. If there is no problem with the wiring to begin with then there should be no need try swapping wiring, but relaying headlights isn't a bad idea while you're already there.

[DerekTheGreat]

Like others mentioned the plugs changed in '89, least Ashley's old '89 had the blade style connectors whereas my '88 has the old socket type for the bulbs and stuff.

[kishy]

Like others mentioned the plugs changed in '89, least Ashley's old '89 had the blade style connectors whereas my '88 has the old socket type for the bulbs and stuff.

It's hit or miss, my '91 has 1157 (round) front bulbs and 3157 (flat) rear bulbs. Or did, until I soldered on new sockets.

[VicCrownVic]

Derek, I found that out this past weekend. At least on a Town car in regard to the ditch/cornering lights. I was looking at those lights on an '88 TC at PG and found they had the old round bulb socket instead of the blade socket. Since he's working with an '89 and '91 he those should be the same if each car has that feature.
I was thinking of the headlight bulbs and didn't take anything else into consideration.

[DerekTheGreat]

It's hit or miss, my '91 has 1157 (round) front bulbs and 3157 (flat) rear bulbs. Or did, until I soldered on new sockets.

Someone must have changed that. I highly doubt the factory would use both on the same car. Our GM trucks (we have knack for finding pre 1990 units) all have the round socket bulbs for the tail lights but of course those are more prone to rusting so since the harness is the same we swap out the taillight board for one that usually has the blade style connectors. Looks factory but not what the trucks were born with.

[kishy]

Someone must have changed that. I highly doubt the factory would use both on the same car. Our GM trucks (we have knack for finding pre 1990 units) all have the round socket bulbs for the tail lights but of course those are more prone to rusting so since the harness is the same we swap out the taillight board for one that usually has the blade style connectors. Looks factory but not what the trucks were born with.

I dunno...I believe it came out of the factory like that. Same combo existed on a '94 Topaz I once had to change bulbs on. A '92 Topaz had the round bulbs front and rear.

[DerekTheGreat]

Well shit in my hat and spoon feed it to me.

I thought it was silly Ford switched the bulbs for '89 with the Town Cars, considering the update that was coming for 1990 it was like, why bother?

[kishy]

Well shit in my hat and spoon feed it to me.

I thought it was silly Ford switched the bulbs for '89 with the Town Cars, considering the update that was coming for 1990 it was like, why bother?

Keep in mind the Lincolns were built in a different plant than the Fords and Mercs. "Design change" does not necessarily translate to "we used up all the old stuff".

That said, there are significant wiring differences between an 89 and a 90 (even Ford and Merc), just on that note, the cornering lamps are fed off the turn signal switch with no relays on a 90...

The body harnesses were assembled by someone, and not as a single piece. So you have different people assembling different pieces of harnesses which are then shipped to the assembly plant and put in the cars and plugged into each other. During the harness building process they will run out of the round sockets and start using the flat ones, without regard for what exact car those sockets are going into.

There has to be some consideration for it as the owners manual of a particular year says the bulbs it uses. I never thought to check if my manual actually says different bulb types for tails and front signals. Will check when I'm in that car again.