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Discussion Starter #1
I had picked up a body computer and traveler from a 1995 Lebaron convertible at our local Pick-n-Pull a while back. This was so I could use the traveler as the 1989 one needed a fuel flow signal. The 1990-91 SBECs do not produce this signal but rely on the data bus for this information. The BCM is the source for the data bus power.

Once I had it in hand and looked at it's various functions I realized it replaced the chime module, illuminated entry and courtesy light delay, intermittent wiper module, key in and headlights on warning as well as including an audible low fuel chime.

Since I had gotten the BCM and about 2 feet of the harness I decided to use as many of it's features as possible, eliminating the other modules. Everything work flawlessly as I was working on other areas, until about two weeks ago. I went to start the car and turn it around so I could evacuate and charge the AC system. Doors were locked (it also has the autolock feature) and the battery (new) was completely dead. I hooked up my battery charger on the 2 hour setting, and started some other items. The door lock/unlock relays started buzzing, so first thought was pull them, while I was removing them something in the body computer started smoking at which point I pulled the plug on the charger, smoke continued then stopped. I had pulled the negative cable off during this time. I removed the body computer and reconnected the battery and finished charging it. I opened the BCM case and found one of the transistors very much a crispy critter, but no other damage.

The original label with the PN is illegible and was when I got it, is there any way of telling which BCM it is? Second, does anyone have any idea what transistor would have been in the Q153 location?

Thanks.
 

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The possible BCM part #'s are 4672291 (base) and 4672293 (premium).
I would think that the premium BCM would support the Traveller.
ePartsLand shows one:
ePartsLand - Chrysler (at https://www.epartsland.com/collections/chrysler?page=2 )
Does this look like yours?

The large transistor is to drive and dim the dome lamps to off (theater lighting). The incandescent bulbs are a fairly high load and this transistor was known to get hot and fail. Heat sinking with compound may help extend life. I do not know the transistor part #.
Check the courtesy lamp circuit for excessive current draw.
 

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Discussion Starter #3
That does look like it. I actually only had two of the interior lights connected, the ones under the dash, what has me puzzled was the power lock business, the relays are the standard Bosch cubes and the ones I had for the lock circuits are actually Chrysler relays. The transistor that smoked was one of the little 3 lead ones with no heat sink.

His price is pretty good too. Thanks!
 

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Discussion Starter #4
Here are some pictures of the board and damage. The transistor, Q153 was completely burned up and when I went to remove the remnants of it the E pin hole came off the board. In the overall picture, the device on the heat sink appears to be an SCR as the pins are tagged C D G. It is connected to the interior light pin, #25 in the natural connector.
DSCN3543.jpg DSCN3545.jpg DSCN3546.jpg
 
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