Squirrels, I checked mine and got 0.07 volt (70 mV).

Yeah, there is something to that. Just found out about it recently. It even eats GM composition head gaskets apparently because a guy at my work had to replace his on a Chevy Lumina with 250k mile on it. However, I have owned two Saturns (GM) and a Ford PU with DexCool and never had problems with it. My Dodge truck had DexCool in it when I bought it and didn't seem to give any trouble. However, I need to contact FelPro and see if they have any issues with DexCool on their head gaskets (mine are not composition).

 

My 2002 Cavalier, which was totaled one year ago, had 147,000 and the DexCool was still bright orange. The engine ran like a Swiss watch; however, the Blazers and some other GM vehicles with the 6-cylinders were getting eaten up by the DexCool.

 

My '84 Ram Charger had a large wire connected from a radiator mounting bolt to the same chassis ground as the battery (drivers side fender as I remember). Remember reading somewhere that it helped prevent electrolysis. Don't see one on my '94 Ram.

Would it be possible for you to remove the transmission cooler cover on your old radiator and either provide a photo or a description of the cooler? Have often wondered what's inside.

 

The Trans "cooler" is no more than a oval chamber that is only as long as the 2 trans line ports, and about half as thick AND wide as the plastic radiator mounting pillar. The cooler gets surrounded by coolant and that's it, I'm not surprised our tranny's burn up after seeing it.


The voltage in my rad was -.15 when I had the multimeter set at 20V. That seems too high. I read this article and tried pulling fuses to get the voltage in the coolant to change and nothing would.

Now I'll be quite honest here: I'm a bit of an electrical 'tard. Should I have the key on when I pull the fuses to check the systems? Can I do that without blowing fuses?

 

Wow, I actually read the whole article and understood it. Very interesting.
Pulling a fuse with the key on should not blow it. The fuse should only blow when overloaded.

 

Okay, I really am a tard.

Those voltages are are well withing tolerance if that article is to be trusted. I'll try to add a few ground straps to the engine bay and see if that doesn't help.

 

I don't think understanding the article makes me smart. It was good info but I didn't see solutions other than verifying all factory grounds were good. You'll be the smart one when your truck is all fixed.
I have been exposed to electrical stuff most of my life (I even have some sparky edu-macation). Electrical circuits are very mysterious for most people because they are not able to get any exposure or experience. Not knowing volts, amps, fuses and checking circuits doesn't mean someone is stupid. It just takes time to get familiar with them. Just like learning anything new.
Peace.