Hey all, I have an 84 240 DL that has a problem I cannot figure out. Like many others of this vintage, there are numerous wiring insulation issues but this is different. I cannot seem to keep the battery charged. Runs for a while when the battery is fully charged. Then eventually will not start or runs very poorly and then dies. Replaced the alternator and numerous wires and the battery. Still same thing. Pulled the neg battery terminal while running, and the engine idles poorly and dies. Sounds like the alternator so I took the "new reman" back to Advance and they checked it on their machine and it checked fine. I am not convinced. Is there anything between the alternator and the battery?? Starter maybe??Something that could break the connection. I get 12 volts on the battery and the alternator red lead when the battery has been charged. What am I missing? I suspect a wiring issue and probably a bad alternator. Any help is greatly appreciated.

 

The battery cables could actually be bad. Also check the battery to chassis and engine to chassis grounds and make sure the alternator itself is properly grounded.

 

thanks cycleboy for the input. These are things we have either done or were going to do. Just an update. Based on another thread with a similar issue, we checked the fuse panel and sure enough fuse 13 was blown. Replaced it and lights came on that had not before and it fired up and ran well for a bit. Then about 10 minutes into the my drive the lights started dimming and then it died. Once again fuse 13 was blown. The million dollar question is what else does #13 feed?? Blinkers, brake lights or what? I am unable to find a full wiring diagram, so if anyone has one and can tell me what #13 feeds I would sure appreciate it. Seems this model has a known history of wiring problems. Thanks in advance.

 

with a fully charged battery, when the engine is running, you should read something like 13.6-14V at the alternator red wire or the battery. might take a bit more than idle to hit this, say 1500-2000rpm. if you're only seeing 12V, your battery isn't charging.

according to my bentley 240 book, fuse 13, 8 amps, on a 84 240, goes to,...

1. fuel pump relay
2. hot start injector
3. relay/thing #181 not listed in diagram index (maybe another hot start injector?)
4. hazard warning switch and flasher widget

looks like fuse 13 gets its power from the ignition switch.

 

You need a multimeter to go further. Alternator should put out around 13v at idle. DO NOT EVER disconnect battery cables or alternator cables when engine is running, it will more than likely destroy the diode pack in the voltage regulator.......which will, oddly enough, allow the battery to discharge through the alternator when shut down.

 

OK so I replaced the fuse again and things went back to normal and then I remembered the rear left three lights, turn,brake and backup, are wired together. As long as I do not use the left turn signal, all seems good. So does the fact that the 3 are wired together and drawing more current account for blowing the fuse or is there a short to ground that is blowing the fuse? Perhapos both. I guess I need to get into that rear light housing and see whats up. Anyone have thoughts on this issue?? Suggestions? Thanks again

 

what do you mean, the 3 lights are wired together?

the brighter tail light bulbs are 21 watts, which is about 1.6 amps (car bulbs are rated at 13.6V nominal, watts == volts * amps, so amps == watts/volts) even if all three were on at once, 1.6*3 == 4.8 amps, which should be well under any fuse.

 

pierce

I believe someone has wired several lights together but have not gotten that far yet. I was hoping the current draw would account for the fuse blowing but as you said, probably not. I think there is some bare wires somewhere or a terminal box that may be shorting or something of that nature. Will update you when I find something. Thanks

 

well, if those three lights were wired together, then they'd all light up at once if you used any of [brakes, reverse, turn signal]. Also likely would give the brake light warning sensor module a hissy fit. I looked at the diagrams in my bentley 240 book, looks like all the tailights are wired to the failure sense module, and it in turn is wired to the various switches and such. of course, the diagrams don't indicate whats inside the black box module.