Brain Storming Car Problem

[AzRednek]

My Isuzu SUV goes dead and sometimes won't start for some reason. It runs fine and every now and then starter barely turns, won't start and seems like battery went completely dead. Let it sit for 30 or so minutes fires really get up. Radio stations has to be re set and odometer goes back to actual miles from the trip setting same as it would if battery was temporarily disconnected. Two year old battery load tests just fine and charging system with lights, a/c, 4 ways, interior lights, cig lighter and everything else I can turn on and alternator stays in specs. Checked and cleaned battery terminals and circuit tested cables and wires connected to starter or charging system and everything fine.

 

What's puzzling everything works but about every 2 or 3 weeks it goes dead. Let it sit or jump start back to normal. My first thought was a flat spot in the starter armature but with radio an d speedo resetting like battery being disconnected I'm lost.

 

Any suggestions even if way out there appreciated

[karlunity]

Battery I think.

Wires may be a issue if the heat is very great in your garage...that could be a factor. expanding and contracting

 

But I would try a new battery first.

 

karl

[Dr.Hess]

I would lean towards starter and a moderately weak battery. A bad starter will draw a huge load, which with a somewhat weak battery, or even a good battery depending on the load, will drop the voltage, which is what is resetting everything else. Just my SWAG.

[brokengun]

I have rebuilt several staters in my life time and still keep on the shelf, parts to rebuild MT10, MT30 and MT35 Delco starters.

 

I had a similar probelm with an MT10 delco starter. The problm was a short on the Communtator. One contact on the communtator was shorted, while the rest were fine.

 

When the starter would try to start from that one shorted communtator conctact the battery seemed to be dead. You could wait a little and allow the battery to rest the starter would then work.

 

What happens is this; when you have a short in the comuntator on one contact, it still allows the starter to move slightly, even though it seems that the battery is dead. When you let the vehicle set and return and try again the starter may now work because the slight rotation from an earlier attempt allows the starter to get past the shorted contact on the communtator.

 

A short in the communtator kills a battery fast and the voltage drain/loss causes your system to restart. While your battery is 2 years old, shorting it out like this will shorten battery life.

 

You can test for a bad comuntator contact by using a ohm meter.

 

My call is your starter is bad

[AzRednek]

Turned out to be the battery but also might be the starter. More later after I get another cable modem.