hey guys, my first post here.. my names trevor.. I'm starting to learn to wrench on my own truck slowly.. i just recently replaced my heater core myself a few days ago.. it took me 2 days.. roughly 2, 6-7 hour work days.. anyways, i unbolted the dash, and just moved it back.. then i cut the old cores pipes off with a hack saw.. then pulled them out.. when i put the new core in.. instead of unbolting the ac unit.. i un-crimped the new heater cores pipes.. slid them threw and then recrimped them on with vide grips. i replaced the thermostat also.
after i put everything back together and filled the rad.. my battery was dead? i don't know why it showed no signs of weakness before this.. starting in -20+ temps... i disconnected both + & - connections.. which were off for about a total of 3 days, i figured maybe that may have drained it. ... So I jumped it with my booster pack.. and it wanted to die right away, i had to keep it revved up for about 20 mins then it would finally idle without dying.. let it idle for awhile.. got the heat going and it was HOT... but I seem to have lost different blowing options except the defrost.. i drove the truck around the neighbourhood for awhile hoping it would re charge the battery, but it seemed to over charge up to 18 volts/max... so i shut it off and let it cool, then reboots it and go home, it did this a few more times.. i left it for a couple days and reset the computer this morning.. by turning the key 3 times.. then it fired up.. it would start on its on for awhile then suddenly wouldn't again..

sooo... I'm asking.. what do you guys think? I was going to pickup a new battery AND alternator on friday.. and replace the battery.. then see how it runs.. and then maybe the alternator depending on how things go... maybe i should just replace both right away? i was getting code p1549 tonight..

 

Leaving the battery disconnected shouldn't discharge it.

Turning the key on/off three times does NOT reset the PCM, disconnecting the battery for a few days sure will though.

Voltage regulator is in the PCM, if it isn't charging properly....... may need to replace the PCM, or, go to an external regulator. (only choose the latter option if you are comfy doing wiring......)

Vents are all vacuum powered. My guess is, the vacuum line providing vacuum to the control head is disconnected, or broken..... which may mean pulling the dash again.

If you don't have a service manual for your truck yet, download one from here.

Welcome to DF!

 

thanks for the quick reply! i appreciate it!!.. Today I went and got a new battery.. she cranked perfect and is running good.. I think i should have done the ac condenser while doing the heater core, but i want to redo the heater core anyhow and add my own mod.. so i will wait until summer time to redo everything its no fun in canadian cold wrenching on the truck.. thank you for your advice!!
next up next week will be u joints and wheel bearings