Strangest electrical problem ever

Hopefully next time you'll be in your garage to troubleshoot it. The click is typical of "not enough juice to the starter" so you're looking at weak battery, keyswitch, loose ground wire on the battery, etc. etc. etc.

Ken

 

Check the negative battery cable for corrosion, both on the battery and at the other end. If you have one of those old cut-off switches (POS, get rid of it), grounded with an old braided ground strap (POS, get rid of it), remove them and get a new negative cable and ground directly to the body. Be sure to clean up the grounding location and the terminal. After that, spray some battery corrosion preventer on the terminal and the place where you ground to the body.

The biggest cause of most electrical problems like that is a poor ground. It may be grounded well enough to allow low-amperage things to work, but not the current draw needed for your starter motor. After that, check the cable that runs from the battery to the starter motor, including all intermediate connections, and make sure they are all clean and tight.

I had the exact same problem with my Mondial when I got it, and changing the cable helped. Ultimately, I ended up having to change the battery. If your battery is more than 3 years old, there's a pretty good chance you could need a new one, but I'd check the obvious first -- the ground connections.

 

Ah, yes, an ‘84 Mondial Cabriolet.....

Obviously the main ground from the battery to the chassis runs through the radio antenna: Winding down the antenna reduces the distance the current must flow and, as the sections collapse into each other, increases the thickness of the aerial. As electrical resistance is inversely proportional to the cross sectional area of the wire, well, your car starts!!
Now if you replace your Italian antenna with an wire coat hanger the problem will disappear. Mind you, the radio will only be able to pick up banjo music.....

OR:

Damned if I know. Sorry I can’t help.

 

Mine is an '84 Mondial QV coupe. In my experience, especial with old Jaguars that are plagued with Lucas problems, electrical components sometimes act in illogical ways. Corrosion on the terminals or in that cutoff switch can reduce current flow enough that the starter won't turn over. It's possible that the antenna is drawing current in one position, but not in the other, so repositioning it frees up enough additional amperage that the starter will then turn over.

As I said, I had the same problem in my Mondi, and changing cables and battery took care of the problem.

Steve

 

It would have nothing to do with the antenna.

I would get a voltmeter/multimeter and measure the actual voltage drop in the starting and charging circuits. It will help to isolate the fault. Clean up all your ground and + cables etc.
What you are describing though resembles a very common problem in Ferraris of this era (and many other cars). It's sounds like voltage drop in the solenoid pull in circuit. A simple relay mod would fix it.

 

My 512TR acted just like that too often so I changed the solenoid and seems to be working fine.

 

But why the heck does it work if I reposition the stupid antenna? It just seems very odd.[/QUOTE]

Hi. Seen this before in a situation where the car wouldn't start until the horn was sounded!

Sulfation (the white powder) builds up around a battery terminal. Overnight, it adsorbs moisture, which raises the electrical resistance. When you go to start it in the morning, there's too much resistance to get the 400 amp starter circuit to function, but if you energize an auxiliary circuit with a lesser draw, there's enough amp flow to vaporize the moisture. Then, the starter circuit can function.

Hope this helps,
Al

 

I had a strange electrical problem with my BB512i a couple of years back. The water temp started running around 100c rather than the 90c it had been running ever since I first got it. I replaced the temp sensor, thermostat, fusebox and had the radiator recored to no avail. It turned out to be bad alternators that were not putting out enough current to keep the fans turning full speed. After having the alternators rebuilt for a couple hundred bucks, the water temp went back to 90c.

 

my 512TR did, too and it had new battery, new solenoid and new starter. to this day, i still don't know its cause.

 

A simple relay mod would fix it.[/QUOTE]

I have had this problem chronically for two years on my 308 GTS. Numerous remedies suggested here have worked for a while. Ultimately, the "clicking" returned. The final fix (for my car)--as Bruce suggested--was installing a relay switch to enure full voltage to the starter. This is especially important if the battery is far from the starter, as it is in the 308. Since the relay switch was installed, my car starts on the first try every time.