I was able to return it. Good guys down at New Cats, and I had no idea about all this.

 

Oh gotcha!

 

@Discox7 I drove around today in 90+, touched 209 briefly, but was in traffic at 200-202. Only difference was that I never put the Climate Control fan over 3 bars. A/C blew cool, and everything else the same. The overheating issue was during AUTO operation.

IMO I have some kind of electrical problem, and it is somehow affecting the operation of the A/C. My voltage begins fine, but as I drive the voltage drops, which makes me think the alternator is failing. I have a 150 amp RR alternator coming, and until then I will just not use AUTO for the cabin fan. Then I will test with A/C in Auto.

 

I'm pretty sure if you use Auto for the climate control it will cycle the AC on/off vs just setting the temp to say 64F and leaving it there (depending on your ambient temps). So with that being said it would turn the Efan on/off which would make your temps vary depending on what it was doing at the time. Here in TX during the summer it's LO/LO, recirculate on, and max blowers so my AC is basically just ON the entire time I'm driving. Now in the cooler months or evenings I do catch myself using Auto, but I haven't been paying attention honestly to see if the Efan goes on/off. I know it will remain off usually until you hit 85F or above, but in Auto I'm not sure if it stays on the entire time or not. If it cycles the compressor off I'd guess to think it would eventually cycle the Efan off as well.

Just a thought

Down here in SETX I honestly don't idle my D2's for long. In normal summer driving I'll see 188-206F usually driving down I-10 at 65-80MPH. It will climb, then stop, then drop, and repeat the cycle. In traffic it will climb and one time in thick Houston traffic I saw 212F, but once I got moving it went back down into my usual temp range. 215F is honestly the temp range I start to silently panic, if it jumps up past that it's either slow down immediately and see if the temp drops, and if it doesn't pull over shut it down and inspect it. Both my 99 & 02 are darn near identical when it comes to how the cooling system performs. The 04 runs really cool for some reason and it actually sets off a P0126 all the time for not reaching operating temp quickly enough. It seems to run 5-8F cooler vs the 99 & 02. Only difference is the lack of an oil cooler on the 04 which would make it have a little bit less heat in front of the radiator.

If I'm driving thru town in the 99 or 02 (aftermarket bumpers/winches) at speeds of say 35-45MPH I am normally in the 188-193F range. If I pull into a parking lot and sit for a few minutes it will very slowly start to rise at first. Like 193, 195, 198, 200, 202, and then 204 over about 10min. Then once you get into the 204 range it will jump to say 210-212 and I honestly shut em off at that point. I'm not a fan at sitting at idle no matter what I'm driving in TX. It's just a lot of stress on the vehicle. Now off road to keep it cool out on the trail I'll keep it in 4Lo M mode in say 2nd gear and my RPM's will be higher and I can putt putt around all day at 188-193F out on the trail no problem.

 

Good luck with the alternator upgrade hopefully it takes care of the low voltage and temp issues. I’ve been fortunate with my charging system so far but my days coming😁. Would appreciate it if after your alternator change you could get another temp from your a/c compressor while it’s running especially with the ambient temps you’re having. We have been mid to hi 80’s here with some hi humidity so I’m really hoping to get this figured out. Also anybody else who wouldn’t mind getting a temp reading off the a/c compressor when everything is up to operating temps I would really appreciate it. I took some readings from the driver side of the a/c compressor casing and was seeing 220+.

 

@best4x4 thanks for the insight. I have read the A/C Description in Rave, but missed the Aux Fan cycling off. That could well do it.

@Discox7 I will re-check for you.

 

No problem

 

Collie I did a little testing for you today. I had to meet up with a guy to buy a G-Shock watch so I drove about 10min. I then sat at idle for 15-25min and I watched the temps on purpose. On my 02 Kalahari with the 180F Britpart Thermostat, 620-112 fan blade, and Hayden 2991 fan clutch I started off at 198F, then it went to 200F where it sat for a good 10min, then it went to 204F and once again sat there for about 5min. Then it hit 206F and stopped going up. This is with the HVAC on LO/LO, recirculate, and max blower. My stock Bosch 130amp Alternator was sitting at 13.5v as well with all efans on.

 

Thanks a ton Best. My alternator is definitely suspect. It’s going down to 12.8, and 12.7 at times.

In it’s defense I am running two electric fans, not the viscous fan, but they don’t pull THAT much voltage.

My 150 amp is on the way, so I will report back when it’s in.

 

Good deal & have a great weekend!