Intermittent No Start

[GElliott]

A dozen times now, I shut my truck down for just a few minutes and it will not restart. No slow turnover, just a completely dead key. Often happens after a several-hour drive then short stop (refueling etc). Usually a short stint on a battery charger, a jump from another vehicle, or even a 50 A jump box will get it going. Batteries brand new (both reading about 12.6V right after the last no-start), clutch interlock switch OK, voltage gauge reads normal when running. Not acceptable for a truck that is often 50 mi into the Rockies with no other traffic or phone service! Any thoughts?

 

[MLee]

I had a period of no start some times, I recently switched the relays in the power center for one that gets little use and so-far no more NO starts. might try that.

 

[GElliott]

So I'm afraid to ask because I think I know the answer. On the '06, is the starter relay part of the "integrated power module," ie not replaceable on its own?

 

[ColemanR]

You say it needs jumped to start Id be curious what the battery voltage is at that point. My next thought would be the starter the next time it does it smack the starter while someone turns the key. Probably has a bad contact in the starter.

 

[Prairie Dog]

Could easily be starter contacts. I recently replaced mine with the bigger ones and it was an easy, 1hour job.
If you have a lot of miles on it, it may be worth doing as preventative maint.

 

[GElliott]

Another incident at the local grocery store p-lot. No crank on 1st try with key, hesitated and then cranked on 2nd (luckily!). Batteries reading 13.0V when I got home 10 min later. Sounds like I should try some starter contacts.

 

[Missouri Mule]

General rule by thumb: if the engine starts in the morning ( first start of day). But doesn't start later the problem is the starter gets hot and needs more juice to make it spin. Could be bad alternator. Need to check voltage before you jump it. If relay was bad it just would not start.

 

[wirehand]

Had the same symptoms as well. My research showed that the computer was seeing an increase in amperage going to the starter and would trip a "breaker" and not allowing 12v to the starter relay. This turned out to be an easy run around by mounting a hidden start button in the cab and intercepting the yellow wire that comes out from under the drivers side cowl. This wire goes to the starter, so sending 12v will spin the starter.

A way to diagnose if this is your issue, is to use a jumper wire from the battery to the connector on the yellow wire. Of course after making sure it's in neutral/park.

One point to consider is if you have any one that might be screwing around in your truck that might be tempted to push this button, either it should be hidden or an ign. hot source.