Chrysler Repair/'90 Lebaron fusible link to ASD blows
QUESTION: Why does my jumped 22gauge fusible link keep shorting out a few inches from the relay #2 (Relay= 2 R/wt wires,1 DkBl,1 Bl/wt, 1green) the blue triggers the test bulb w/key on, w/o the link jumped. The other relay #3* = 2gry,1gr,1bl, 1bl/Or will not light the test bulb with key on/off. The two relays on the passenger wall will not activate the test light any. Any suggestions. None of these OEM relay numbers identify the part.#1 is 4373677 66317 worked(or/bl lit bulb), #2 is 463851 A1970, #3 is 5233210 50732. They are not secured in any special order. Using wire color to the plug #1 likely start-run-fuel, SCI,Tps. #2 likely ASD output #3 radiator fan-AC cut out. ??
ANSWER: Hi Mary,
The only fusible link that is 22 gauge is white and goes to the ASD relay. That relay sends current to the fuel pump, the fuel injectors (I assume this is the 3L engine, correct?), and the spark ignition coil, all via the dark green/black wires. If that white link is blowing and soon as you turn the key to "run" then one of those 3 pathways has a short to ground which is overdrawing the fusible link. I would unplug the dark green/black wire at the ASD and measure its resistance to ground and verify that is is close to 0 ohms. Then check each of those pathways and measure the resistance to ground of each pathway to determine which one is shorted to ground and then look at the items on that pathway to see if you can find the specific short to ground. The wire dark green/black wires would also be of interest if you can't find an item which is shorted to ground.
The relays on the passenger side are probably not relevant to the white fusible link being blown.
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QUESTION: My Vin is 1C3XJ4534LG425324. I have a wiring supplement for G/J body, which I think applies. Not sure if Eatx or ATX 3.L, HiLine model mfg date 89, model date 1990.Diagram shows all Green/Bk go from neg terminal to grounds,+SBEC tan-blk which is a relay cavity #11, also cavity #20-SBEC. On positive terminal it goes to a fusible link#A-11, then turns black gray to natural plastic connector,Blk-gray again to DkGrn. I will check these today. But, can I use any 22gauge wire to jump or does it have to carry a certain amp not to burn up?
ANSWER: Hi Mary,
The only 'true' ground wires are solid black, all the other double color wires where one color is black are NOT ground wires. I have the same wiring diagram booklet you have.
I would not use a simple 22 gauge wire in place of the 22 gauge fusible link wire. The fusible link wire behaves just like a fuse, while a simple 22 gauge wire will carry too much current before it melts. I would not jump across the blown fusible connection until I determined why the fusible link blew.
Do what I suggested in my first response in order to find out why the fusible link is blowing, i.e., carrying too much current.
"I would unplug the dark green/black wire at the ASD and measure its resistance to ground and verify that is is close to 0 ohms. Then check each of those pathways separately and measure the resistance to ground of each dark green/black pathway to determine which one is shorted to ground and then look at the items on that pathway to see if you can find the specific short to ground. The dark green/black wires themselves would also be of interest if you can't find an item which is shorted to ground." So examine the wire as well for broken insulation which lets the wire touch the engine or any other "ground" point.
Once you have found out which of the three pathways (fuel pump, ignition spark coil, fuel injectors) is shorted to ground and fixed it, then you should be able to replace the white fusible 22 gauge wire without it blowing. Don't substitute a 22 gauge wire for the fusible link or you do more damage.
Tell me what you learn and what you are doing.
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QUESTION: Thanks it was clearer this time. I think you said check each wire in the plug for which of the 4-5 wires are shorted, ok. The fusible link no one has except for $50.+ bulk, rust color in U.S. I ordered red 22gauge, 200amp load, heat tolerant from overseas. S/B here by EOM. May I use a 18guage gray interim for testing or should I wait for the 22 gauge. Also am waiting for the salvage to get a car(have advertised to buy a parts car), but with only one white fusible link, chances of it being good are 50/50. I haven't read the follow ups yet, in case there has been more pertinent into. Thanks again. Mary
I would be inclined to troubleshoot this short using a digital ohm-meter. Compare each reading of a wire with reading you take when touching the 2 probes together as your "0". Start by tracing as far as you can from the dark green/black wire of the relay to all of items it attaches too looking for any damaged insulation which may have resulted in contact with any metal surface. Then check the end point items themselves after unplugging the dark green/black wire. Then re-measure the dark green/black to ground which should be infinite with the three items all disconnected from it.
I would avoid using voltage on the circuit by jumping across the blown fusible link as you are likely to blow the jumper (or the 20 gauge fusible that "feeds" the 22 link) so long as the cause of the short has not been found and corrected.