Disconnecting Battery

[Mrforklift]

2004 Trailblazer, I have had to replace HVAC actuators twice and after research I believe the problem was caused by replacing the battery and once it went completely dead.
Now it needs a starter and I don't want to cause any issues with the actuators by disconnecting the battery. Do you think the OBD2 memory savers will help? I also want to install a new battery but not sure how to jump power and remove the starter.

Thanks for any help!

 

[Chickenhawk]

In my experience, the OBD memory savers that use a booster pack work well on our platforms. The ones with the 9-volt battery don't. Also, the memory savers that go into the 12-volt outlet don't work either.

 

[flyboy2610]

I use an OBD memory save with a booster pack. This is the one I got from Harbor Freight. It works quite well.

1700 Peak Amp Portable Car Battery Jump Starter and Power Pack

Amazing deals on this 1700A 12V Jump Starter at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

I bought a Schumacher OBD memory saver cable from Autozone.

https://www.autozone.com/test-scan-and-specialty-tools/memory-settings-saver/p/schumacher-obd-ii-memory-saver-cord/220034_0_0

One important thing to remember: When you hook up a memory saver and disconnect your battery cables, those cables are live! You don't want them touching anything or each other. I put a plastic baggie over each cable, then put a cotton gardening glove over the baggie. A zip tie ensures that everything stays that way until I'm done.

 

[TJBaker57]

Also, the memory savers that go into the 12-volt outlet don't work either.

This would seem odd, since these are connected together to the same circuitry, unswitched, hot at all times. What connects to one connects to all.

 

[flyboy2610]

The memory saver I referenced has 3 1 star reviews on the Autozone website. Why? All 3 are because the cord is too short to reach the cigarette lighter of another car.
Well, d'uh, Homey!
With a power pack it works just slicker than snot on a doorknob!

 

[Mrforklift]

I use an OBD memory save with a booster pack. This is the one I got from Harbor Freight. It works quite well.

1700 Peak Amp Portable Car Battery Jump Starter and Power Pack

Amazing deals on this 1700A 12V Jump Starter at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

I bought a Schumacher OBD memory saver cable from Autozone.

https://www.autozone.com/test-scan-and-specialty-tools/memory-settings-saver/p/schumacher-obd-ii-memory-saver-cord/220034_0_0

One important thing to remember: When you hook up a memory saver and disconnect your battery cables, those cables are live! You don't want them touching anything or each other. I put a plastic baggie over each cable, then put a cotton gardening glove over the baggie. A zip tie ensures that everything stays that way until I'm done.

Ok, no problem at the battery end but what about the power cable at the starter end. Wouldn't that be hot too with the booster hooked up? Maybe not on the TB? It would be tricky to get it disconnected at the starter and reconnected without arching it to a ground.

 

[Mooseman]

Something you have to know about the actuators. It's not the fact the battery is disconnected that they fail, it's because they were going to fail regardless. When the battery is reconnected and first started, the HVAC system will recalibrate them, an operation that a healthy actuator will survive. Even if you use a memory saver, if an actuator is weak or on the verge of failing, it will eventually fail. You're just delaying the inevitable.

And if you do use a memory saver or battery pack, if you happen to short a positive lead, memory will be lost anyway. And you've already replaced most of them.

 

[Matt]

Something you have to know about the actuators. It's not the fact the battery is disconnected that they fail, it's because they were going to fail regardless. When the battery is reconnected and first started, the HVAC system will recalibrate them, an operation that a healthy actuator will survive. Even if you you use a memory saver, if an actuator is weak or on the verge of failing, it will eventually fail. You're just delaying the inevitable.

And if you do use a memory saver or battery pack, if you happen to short a positive lead, memory will be lost anyway. And you've already replaced most of them.

Came here to say this.

 

[Mrforklift]

Got it, sounds like you just disconnect the battery change the starter and you get what you get.
OBD memory savers and jump packs work when just replacing the battery or for short term electrical work.