Hello All-
First a bit about my truck. It's an '81 Rabbit pickup (about 200k on body/guts) with an AAZ engine swapped in (about 30K miles ago with the previous owner). Car also came with a transplanted steering column and rack/pinion from a Cabriolet (from a ? '88 or so Cabrio) because the previous owner wanted power steering. First off thank you everyone for the mass of information that I've been reading as a bystander; it has helped with a great number of fixes thus far.
My current dilemma:
An issue that has been occurring with increasing frequency for about two years which now is occurring during any drive longer than about 10 minute; I will be driving down the road, and quite abruptly, my engine will shut off entirely as though someone just turned off the key. The dash cluster goes out with it, the headlights go out with it and the horn stops noising (although when the steering wheel button is depressed you can hear the horn relay click). The dome light and hazards continue to work.
Typically I coast in neutral to the side of the road and turn the key off. For a short time (although the amount of time seems to be getting longer now) if I try to turn the key to the on position, no lights appear on the dash cluster, the engine doesn't turn at all; nothing. It's as though the ignition switch has become non-functional (although again the headlights are gone and the only the horn RELAY fires; which makes me suspicious that it is not the ignition switch itself since these usually operate with the keys out of the car). Then usually if I wait 5-10-20 minutes, if I try turning the key back on, everything in the dash cluster lights back up and it is business as usual. When I turn the key to crank, the starter motor sounds nice and vigorous (not at all sluggish) and the engine starts right back up. The horn and headlights come back and I drive on my merry way. The engine starts nice and quickly every time so I assume it's not the battery or starter that is the problem.
In an attempt to fix the above symptoms I have done the following:
--Removed the aftermarket cruise control as it wasn't working anyway and I wanted to simplify wiring under the dash.
--Changed my battery post connectors to marine-style ones.
--Entirely replaced the main hot wire going to the starter motor from the battery.
--Entirely replaced the main ground wire coming from the batter to the transmission mount.
--Added independent ground wires from the negative battery post to a valve cover bolt and to the alternator.
--I replaced the voltage regulator on the alternator.
--Tested all of the fuses (which seem to be fine)
--Beaten my fists against a brick wall repeatedly.
Despite the above, the symptoms continue. As I am not the one who did the swap, I am somewhat ignorant to the details of how these AAZ engines usually get wired in. Usually the problem is so transient that I don't even have time to get out my multimeter before the problems "fixes itself again". Honestly though, even if the problem persisted I'm not sure I would know where to begin with the multimeter. Any advice would be appreciated. My hopes are that someone out there has had a similar problem and knows of a fix for it. I've attached a picture just in case it demonstrates better than my words did, how I've tried to spruce up my ground contacts. Thank you all.
Kit