QuestionQUESTION: My 95 Chrysler Concorde will not start. The Voltage at the dash fuse panel on the fuel pump fuse only 3 Volts. If I short the other side of the fuse to 12v, I hear the fuel pump. The Voltage going into fuse panel is 12V. What Can Cause a low voltage?
ANSWER: Hi Tom.
I am not certain that I understand what you mean by the fuel pump 'fuse' as the only connection that I see in the fuse box behind the dash that sends power for the fuel pump itself is just a solid internal connection rather than a fuse. Fuse A in the power distribution box appears to be the only fuse on the fuel pump power circuit. Can you give me a number for the fuse of which you are speaking? Do you mean fuse #18 which is needed to operate the ASD and fuel pump relay actuation coils?.
The power to the solid connection in the junction box behind the dash, that goes on to the fuel pump relay in the power distribution center under the hood, comes from fuse A (20 amp, rear-most fuse of the in-board row of fuses in the power distribution box) so see what that fuse reads. That one also sends power to the starter relay and the ignition switch so it is pretty central to operations and would not be very good for that one to read 3V.
So clarify exactly which fuse you are reading 3V and at the time you are reading it what other electrical circuits/components are being called into duty? Does it read 3V with the ignition off?
Roland
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QUESTION: Roland,
Thanks for your quick response. Yes, fuse #18 that is supposed to energize the relays is only 3V (2.8V to be exact) with the key in the “On” or “Start” position. With the key “Off” I get 0V. Also, I was able to find the connector that supplies the 12V to the junction box (fuse panel) by removing connectors until the 3V went to 0V. The Haynes manual wiring diagram says the wire supplying voltage is a 16 gauge dark blue wire. I found that wire on that connector and it has 12V on it. It seems like the junction box is bringing down the voltage to fuse #18. The rest of the fuses seem fine. Is it possible I have a bad junction box? Is there a way to test the junction box that you know of? Can I open the junction box and see if there is any sign of corrosion without destroying it? Or should I try replacing it?
AnswerHi Tom,
That dark blue wire comes from the ignition switch when it is in the run and start positions, and its current is split 4 ways and sent to fuse sockets 14, 18, 19 and 20 internally in the junction box. I would be inclined to simply jumper a wire and solder it between the hot side of 19 to the hot side of 18 (which are the lower fuse sockets) and see if that gets you around the problem. If there is a poor internal connection this would be a simple and 'legal' way to get around it. But first, remove fuse 18 and verify that it indeed only shows 3V as it does when the fuse it in place, just to be sure.
Roland
