In the past, a quick test for GP's was to take a test light, clamp one side to battery positive and touch the other side to the tip; if the test light lit you had continunity= good PG. If one was suspect, pull it out and bench test to directly on a battery. A couple of weeks ago with the deep cold we had I cycled my key a couple of times to help the engine start. Soon after my MIL came on and so I checked each GP as usual and found all of them tested okay with the test light; so i figured it was the buss bar. I replaced the buss bar, but a couple of days later, MIL came on again. So yesterday I went and checked them with an ohm meter. 3 were less than 1 ohm, one was 166 ohms. Took it out and bench tested and it lit up. I replaced it and now no more MIL. I even used a test light with a neon bulb which supposed to not light up brightly with a higher resistance in the circuit. Lesson learned
wow, I had the same issue recently.
I also had the same deal you spoke about earlier with the vanishing coolant when it gets really cold. I don't know what is going on there and I am open to your ideas. Brightest thing I am thinking is the plastic connectors at the heater core shrink when it is that cold allowing a little to escape until the engine warms up. I never lose too much, but don't see it anywhere either???
Coolant loss was my head gasket. I changed it last week and it was obvious where it failed- at the back edge of cylinder #1. Now fires up cold smoother than before also.
Of course I figured that was the problem because the colder it got, the more pressure was building up in the tank, and staying pressurized for even a couple of days. So much was blowing out when coming to a stop off a highway ramp,I was worried that it would ruin my L/S strut bearing.
I never see any coolant and it takes a long while to lose any. I hope no HG in the near future.
Hope for your sake it's not an even worse scenario than me. What is the possibility that you are consuming it? Or if it was the EGR cooler I would have thought you would have evidence of that in the bottle. I have had success using a Snap on combustion gas tester that reads from the bottle;worse case was finding a cracked block on a pal's AAZ Vanagon, but he had an overheating issue.
It only does it when it is around 0f