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53 Chev COE 5100. Original 6 volt system. Optima battery. Have put 00 cables to help slow crank problem. Recently noticed when cranking for awhile that my negative cable, which is maybe 24" long, going from battery to bell housing was hot to touch. Positive cable going to starter was cool. Seems like it should be the opposite. Thanks.

The ground cable might be corroded inside, causing excessive resistance. Using a low-reading voltmeter connected between the starter housing and the negative post of the battery during cranking check how much voltage is being lost on the ground side. It shouldn't be more than 1/10 volt.
Jerry

If the voltage drop test is good then the starter can be bad. Indicated by it's slow cranking speed and the cable getting hot. No voltage meter handy then try a new cable first. Jeffrey

I would recheck the quality of your positive and negative contact points making sure there is a real clean metal to metal contact.

A well tuned engine will not require "cranking for awhile".

Paul_WNC,
After sitting a week or so, the updraft carburator will require cranking a lot to refill the bowl. My 50 COE does the same thing, even though it will start immediately if run recently. This behavior has nothing to do with tuning.

It is interesting that only the negative cable is hot. CmdrGeo you might try another cable, or test, as Hot Rod suggests.

Kent

Thank you all who have responded so far. I will get my hands on a volt meter and see if that tells me anything. Meanwhile, I'm pretty sure both cables are fine. Built them myself last year but will take both off and clean good. Meanwhile, I will admit that my truck is probably not properly tuned, nor is it driven enough. When it sits for 2 weeks, which is not unusual, and the battery is not as fresh as it should be and I'm trying to fill an empty carb bowl, it needs to crank for awhile. Guilty as charged. My question, mainly, was why, after doing so, the negative cable was hot and not the positive.

Geo

So heat is produced where there is resistance. Since most parts of the circuit have very low resistance, any portion that has a little higher resistance will produce more heat than the others. It has nothing to do with positive or negative terminals.

Is the cable itself getting hot, or just one of the terminals? Since a starting system operates at almost dead short resistance, even a slightly loose or dirty connection will produce low cranking speed and/or heat.
Jerry

Negative (ground) cable was hot. Positive was not

Thanks for sticking with me guys. Jerry, when you said that even a slightly loose or dirty connection will produce low cranking speed and/or heat, I went right to the negative cable. I knew the cable itself was good because I just built and installed it last year. But I replaced my battery after doing so and sure enough that neg cable was both loose and starting to corrode. Cleaned the post and cable, greased it up and got it good and snug and I think I'm good. Till next time of course.

Geo

Just a note of interest. Some may not be aware of it so....grease the connection after you make it up. The grease is a dielectric or insulation type material. A car buddy of mine greased his tail lights before installation. They were intermittent till we cleaned the grease up. The copper impregnated grease seems to work well on connections and spark plug threads.

Right, my understanding is "grease" for or on electrical connections does not improve the conduction of electricity at all, (to much can insulate) what it does is later try to prevent/reduce corrosion and in that way grease helps the connection long term.

Some products

Again, thanks guys. Good point, well taken. I must admit I've done it both ways in the past with mixed results. But I took mine apart again this morning and made sure that connection was good clean "metal to metal" and all the grease was outside where it belongs.

Geo