<p>Buddy of mine and I went Jet Skiing Yesterday. He and his dad own a pair of Jet skis but his dad was using the Jeep he usually pulls them with so he asked me to bring the Xterra to pull them.</P>

<p>Since I bought my Altima last year the Xterra only gets driven about once a week or so. It was a hot day and it smelled a little funky inside from being closed up for awhile so I started it up, rolled the windows down a bit, turned on the AC, locked it, and went back inside to finish getting ready to go. Came out 10 minutes later or so, AC was still blowing cold and I made the 30-mile drive to my friends house without issue.</P>

<p>We hooked up the trailer, pulled it out of his garage (down hill) and left the truck running while we loaded up the truck with his stuff. After 10-15 minutes we got in the truck to leave and found the AC was blowing hot. Made the right turn off his street and after making the turn I noticed the right blinker was still on, not blinking but steady on. At the same time I noticed the cruise control SET light was blinking and the temp gauge was at its highest point, the scan gauge showed the temp was 250. Turning off the headlights turned the blinker off (I drive with lights on all the time) and the SET light quit blinking. Once we started moving the temp dropped to normal, around 195. We also found that with the lights off hitting the brakes would turn on the parking lights.</P>

<p>I have a trailer light debug plug that we checked the trucks trailer pigtail with when we stopped. It showed the truck’s wires were working fine and with the trailer unplugged all lights on the truck operated normally. All the lights and wiring on the trailer were replaced about a month ago and I have pulled this trailer since without issue. But the trailer was repainted last weekend so it is possible something was pinched or knocked loose when that was done or since the last time I pulled it.</P>

<p>A little Googling revealed that the SET light will blink due to a bad ground on a trailer among other things.</P>

<p>The truck hit 100,000 miles yesterday on the way back from the lake. In the almost 6 years I have owned the truck it has never overheated until yesterday after plugging in that trailer. The truck began to overheat again on my way home while sitting at a drive through even after the trailer was disconnected. Just to see what the effect would be I put the truck in neutral and increased the idle speed to about 1100rpm and the temperature immediately started to fall.</P>

<p>Could a problem with the trailer wiring damage something that would cause the truck to overheat at idle? Or is it just a coincidence that something in the cooling system failed at the same time? The scan gauge shows no codes, none of the dash warning lights came on, and it has plenty of coolant.

<p>Is there a relay or fuse somewhere that could have been fried that increases the engine RPM at idle when it starts to get too warm? Right now with the A/C on it’s idling around 680 stopped in drive, and 880 in park.</P>

<p>Any Ideas? Thanks in advance!</P>

Could be coincidence and be a cooling problem....

You said "[i].... it has plenty of coolant.[/i]"


This might sound fundamental but.... Be sure to check the level of your "[b]radiator[/b]" coolant (vs. just checking the overflow tank) when cold.

If the radiator is a bit low, my Xterra will run hot to nearly over heating when sitting idling with A/C on. It's only happened twice in 8 years (2001 V6 3.3 4x4). both times I wondered why it doesn't pull it from the tank but it just doesn't :-(

Normally, it runs with the gauge showing in the 1/4 range all the time when operating.