ZachsXJ

So tonight I went wheeling with some buddies, the Jeep did great and the new(used) fuel pump is working perfectly, everything was good and well on the trail and after, then on the drive home from my Gf's house the CEL came on. I checked it and was getting:
Code 23 Intake Air Temp
Code 24 TPS
Code 47 Battery under voltage.

My question is this, what to do about the TPS and and IAT, is there anyway to test them to see if they are or aren't bad?

The code 47 was because I had the heat on and blower on high which was drawing a huge amount of power. I don't understand why turning the heat on(just allows coolant to the heater core) and turning the blower on high would draw so much power as to cause the battery to start draining.

Any help or suggestions would be much appreciated.
(I'm driving a 91 2dr Cherokee with the 4.0HO and a 5spd AX-15)

4.3L XJ

If you went wheeling, that low position on the alternator allows it to get mud and water in it. It would be a good idea to take it off and clean it. That will take care of the code 47. You need to take care of the information in your avatar so we will have enough info to give you some feedback.

troy fritz

Try cleaning your sensors with dielectric cleaner and put dielectric grease on them and reconnect.

fantic238

you mean electrical contact grease, a dielectric is an isolator, exactly the opposite.

ZachsXJ

The check engine light hasn't come back on since last night and I've driven it at least 60 miles since then. The only thing I did different last night compared with any other time I've driven it is I had the heat on and the blower set to high which made my Voltage gauge go down to about 12v. I'm confused as to why the blower/heat is pulling so many amps as to have that effect when high beams have hardly any.

No, he means dielectric grease. anytime I unplug an electrical connection in my Jeep, even the "Weather sealed" ones I put dielectric grease on it before reconnecting. The dielectric grease gets pushed out of the way by the pressure produced to make the connection but surrounds the connection and connectors as such to insulate them(preventing shorts when water gets on the connections) and prevents corrosion.

As to the question about my alternator, its fine. All the connections are slathered in dielectric grease and its a reman unit thats been on less than two weeks. Killed my last one by going into a puddle that came up to my headlights