Wondering how warm/hot should a alternator get after running a while. Noticed after sitting for a couple hour( air temp 80+ ) it was still almost to warm to hold your hand on it.

 

I don't know the temps but mine will get so hot that you don't want to lay your hand on it. I think it would blister your hand after a few seconds.
Joe

 

They get plenty warm, and will remain so from all the heat soak going on under the hood after you shut it down.

 

Since they're bolted directly to the engine, and the engine is somewhat limited to at least thermostat operating temperature, they're gonna' run upwards of 175 degrees at least, plus any self-generated heat.

Able to dependably withstand considerably more than "hot to the touch" should be part of the design criteria.

Pop

 

Here's an exact temp that I measured last Thurs while towing to my current location of Bozeman, MT. I stopped at a rest stop, grabbed my IR thermometer, popped the hood, but first measured all tire, brake, and wheel bearing temps before starting my routine under the hood measurements, so these #'s are after about 5 min at idle with the hood open. Alternator was 205 F, whereas the upper radiator hose (hot one) was 195 F. Ambient air temp was in the 90's, and I got 90 F looking into the front of my Zoodad hole by reaching through the grill. The AIS air box was 100 F, the big hose from the air box to the CCV coupler was 110 F, and the hose from the CCV coupler to the turbo inlet (close to the turbo) was 120 F. The CAC tube from the IC outlet to the intake manifold was 120 F at the connection to the IM, but the IM itself, which is bolted to the turbo was 230 F!!! It would sure be a nice mod to fashion an insulated piece to connect the turbo outlet to the IM instead of a direct metal-to-metal connection!

Prior to making the above measurements, my fan clutch had been locking up during some of the steeper grades, so I know that the under the hood air temps were in excess of 200 F due to the several hours of towing before making these measurements. The above types of measurements are why I claim that an under the hood filter is not the best choice for towing, as it would be drawing air into the turbo that's more than 100 F hotter than with a Zoodad + air box type filter.

 

This is exactly why i am going back to a snorkeled air system... probably the AIS... after towing up throught the mountains when i pull off the highway and stop at the stoplight, my under hood temps go up over 300 degrees...

 

Yes the alt will get very hot under normal conditions. If you have a battery going bad it will cause the alt to over heat. Disconnect the batteries and test them individualy. One may have a bad cell.

 

Thanks for the info, both batteries were new 4 months ago, not that one still could be bad,from the info above things sound normal.

 

how hot is to hot wow.i lost may alt and installed a new one (napa) it lasted two weeks .picked up another one going to try it ,batt check good, alt volts at alt is 14.4 and at bat is 14.4 going to try it again
jim t