question about battery ground wires

hi folks,
I replaced my battery yesterday on my trusty old 2000 Tacoma 4 cly and the positive cable battery connector was so corroded it totally came apart. I couldn't tell if there was a ground wire connected to it or not. (I know there is a ground wire connected from the negative cable attached to the body). The reason I'm asking , I took it for a spin after I installed the battery and the temperature gauge started rising. I thought this was odd since I had the whole cooling system replaced with factory parts by a qualified mechanic about a year or two ago and it has been running great since. I'm worried that I somehow damage something. I did accidentally caused a spark or two while I was trying to jerry rig the corroded connector back on the battery pole so I could drive the truck to the store to buy a new one. ( I also realize I should have unhooked the negative cable first). Could that have damaged the heat sensor or temp gauge? Thanks for your tips.

 

If you hook a ground cable to the positive terminal your gona have a bad day.

 

On my Highlander (few years back); about half of the instrument cluster went blank. After $160 the dealer told me they could not find the problem and it would take $600.00 more for a full electronic check, this did not include any promise that the problem would be fixed. The tech complained about my speakers...said he had no idea what I had done. Apparently he had never seen external x-overs. Regardless, I had them close it up and took the car home to play with. About an hour in, I found that there were multiple ground wires (3 if I remember correctly) going to several points on the engine block, fuel rail and head. I cleaned up the ground connections and my instrument cluster came back.

Moral of the story: you seem to have a lot of corrosion under the hood. Check the connections; ground and otherwise.

 

If you positive cable was that bad I can only guess about the other connections

For what it is worth one of the water temp grounds on the 4 cylinder is under the coil bracket

Then the sending unit is grounded into the manifold

You might want to check those for being corroded

 

thanks for the replies. I took it for another spin this morning and the temp gauge did start spiking. I then touched the engine and manifold and they didn't really seem hot. I will check the water temp grounds. But then again, before I changed the battery everything was performing great

 

plus, the engine was pretty clean except for the battery terminal

 

This is a bit confusing as you don't 'ground' a positive wire. If I recall correctly from looking at a Gen1 battery Q in another thread, the larger gauge wire goes to the starter and the smaller gauge wire goes to the fuse panel. That smaller wire comes from the alternator and charges the battery; this same wire powers the fuse box and is protected with the alternator fuse. The ground cable also has two wires; the thicker gauge goes to the engine, usually near the starter; and a smaller gauge wire goes to a chassis point near the battery. A third ground wire should go from the engine to the chassis down below near the steering column.