Starting gremlin
This should be easy to find, as you are losing power somewhere.
FIRST thing to do is remove both battery terminal clamps and CLEAN them. Buy a good "battery brush" if you don't have one, like this:
If that does not clear the problem, then find out WHERE you are losing power
Get your test lamp "rigged" with clip leads so you can see it while reaching in to turn the key to "crank."
Also see if turning headlights on/ off affects problem
Start by clipping test lamp to engine block, and starter relay battery stud
Does it stay lit when problem appears?
Then problem is further downstream
If it goes out, it's right there somewhere, battery, cables, clamps. Cables can fail internally with corrosion!!
If you got a light but no crank in the first test, move further on
Backprobe the bulkhead connector where the fuse link enters, with lamp grounded to block. If it lights / no crank, problem is elsewhere.
Probe the push one yellow wire at the starter relay. No/ dimming light at that point means it's between the bulkhead (in test above) and the starter relay.
MOST LIKELY in this case is the bulkhead connector itself
Other suspects are:
Failed / loose ammeter connections
Bad connector/ bad ignition switch
Failed "in harness splice". This is a factory welded splice a few inches into the under dash harness from the black ammeter connector. You'll have to untape it and follow it down.
To check these out, Access the igntiion switch connector under the column. Find the battery feed to the switch, and try to crank.
IF you get a dimming/ poor light, it's between the switch and the bulkhead, IE ammeter, splice, or bulkhead itself
If you get a good light, probe the outputs of the switch, the yellow, the dark blue. If these are nice and bright when problem occurs, most likely is where those wires go through the bulkhead.
This should be easy to find, as you are losing power somewhere.
FIRST thing to do is remove both battery terminal clamps and CLEAN them. Buy a good "battery brush" if you don't have one, like this:
If that does not clear the problem, then find out WHERE you are losing power
Get your test lamp "rigged" with clip leads so you can see it while reaching in to turn the key to "crank."
Also see if turning headlights on/ off affects problem
Start by clipping test lamp to engine block, and starter relay battery stud
Does it stay lit when problem appears?
Then problem is further downstream
If it goes out, it's right there somewhere, battery, cables, clamps. Cables can fail internally with corrosion!!
If you got a light but no crank in the first test, move further on
Backprobe the bulkhead connector where the fuse link enters, with lamp grounded to block. If it lights / no crank, problem is elsewhere.
Probe the push one yellow wire at the starter relay. No/ dimming light at that point means it's between the bulkhead (in test above) and the starter relay.
MOST LIKELY in this case is the bulkhead connector itself
Other suspects are:
Failed / loose ammeter connections
Bad connector/ bad ignition switch
Failed "in harness splice". This is a factory welded splice a few inches into the under dash harness from the black ammeter connector. You'll have to untape it and follow it down.
To check these out, Access the igntiion switch connector under the column. Find the battery feed to the switch, and try to crank.
IF you get a dimming/ poor light, it's between the switch and the bulkhead, IE ammeter, splice, or bulkhead itself
If you get a good light, probe the outputs of the switch, the yellow, the dark blue. If these are nice and bright when problem occurs, most likely is where those wires go through the bulkhead.
