I don't like to read a post twice from different forums but I have had better luck in this group. So I am posting the same problem here that I put on the electrical group.

I have a strange problem that occours when I attempt to start my 93 Aerostar. Sometimes the panel lights are dim when I turn the key and it doesn't turn over or even click. Then if I turn it off and try it again it starts just fine with the lights looking normal. Also I noticed that the dash voltmeter is at the "A" in normal and wiggles just a little. If I turn on the head lights or anything else with a electrical draw the voltmeter jumps dramatically. My wife said she thinks these were the same symptoms she had seen previously with a battery that was about to die.

Thanks
Doug

 

I had been fighting the weirdest problem for month's. Many people here offered excellent suggestions but to no lasting avail. The major overall symptom is the random complete loss of power or dramatic loss of power. Some mornings you come out to the Van and there is no power anywhere but the battery. Shake and pull wire, close door, slam hood. Any or all of these and the Van power may come back temporarily or may come back and be fine for a few days. Also, out of nowhere if you put a load on the electrical system such as lights, or air, the power will drop all the way to off and then kick back on.

There is a red wire between the starter solenoid on the starter and the starter relay on the top driver side of the engine fender wall. It is a 10 guage wire and gets bolted on by itself on one of the terminals on the relay. When I carefully would shake this, it would cause all power to go out and then all power to go back on. What did not make since was, when I took the wire off completely, the power would be on, but of course the starter would not start.

I determined the top 8 to 10 inches held the problem, so I cut off that portion, including the terminal crimp, and then stripped all the insulation off to see what the wire looked like. The top 6 inches were very black, as if it was arcing, but the wire was not broken in any way.

I crimped a new piece of wire and new terminal eye onto the existing wire and reconnected it and the power seems very stable now with no strange symptoms.

I can only guess that somehow moisture got into the wire and slowly caused it to deteriorate. Under certain conditions the wire would arc inside and trip some kind of circuit breaker in the electrical circuit. I really have no idea why this wire that was not shorting out against anything elese could cause all power in the car to stop, but hopefully, it's repair has caused the problem to go away. I will totally replace the wire soon.

Hope this helps.

John

 

Our van did the same thing. In our case it was a faulty neutral safety switch. Sometimes turning the key back off and trying again would work, sometimes not. We could put the shifter into "N" and it would crank right up. Or even just take it out of Park and put it back.
Like JL's problem, some 87-91 F150's were known to corrode a particular ground wire internally that would cause all sorts of troubles. Internal corrosion is often difficult to detect and a real pain to diagnose sometimes. Hope yours is a simple problem!

 

The neutral safety switch tends to rust. Once a month, I clean it with a wire brush and spray it with WD40. That way, I never got the starting problems again.
If you do this, just make sure to disconnect the negative terminal of the battery. Because if you touch both the neutral safety switch AND the positive contact of the starter relay with the wire brush (you can't avoid it), the engine will start up

 

My old 1977 Cougar was giving me electrical fits (I HATE ELECTRICAL PROBLEMS!)--no heater fan, A/C clutch not working, my turn signals, not charging, & sometimes no wipers. What I found out about these seemingly-unrelated gremlins was they shared one thing: all ran off the IGNITION SWITCH. This could be your problem. I'm not sure where it is in these vans--in most 80's cars (5.0 Mustang, etc), it's in the column, mine was on the firewall (what a PITA). My gut says the Aeros would have it in the column.

 

Could the Neutral Safety Switch also cause my wiggling voltmeter and big draw down of power when I turn on the brights.??

Thanks
Doug

 

That sounds like a connection...I suppose it COULD be the ignition switch............

Hmm.