How to change a heater core yourself

Hello,

You must start by disconnecting the battery to avoid electrical problems when doing the job. Here is a guide that will give you an idea of what you are in for.

https://www.2carpros.com/articles/replace-heater-core

You will need to vacuum down and recharge the air conditioner system here is a guide for that as well.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

Check out the diagrams (Below)

Please let us know if you need anything else to get the problem fixed.

Cheers, Ken

First, I'm not sure why there is an electrical current in the coolant. There really isn't anything that should cause that. Also, it wouldn't cause additional pressure. The lid on the radiator is set to release pressure when it reaches a certain point, so excessive pressure shouldn't be an issue. However, if the lid is bad, it could cause additional pressure to build. Has the radiator cap been checked or replaced?

That is call "electrolysis" and if happens when there is a ground problem somewhere and the current is finding it's way back the the battery ground by going through the cooling system. The root cause is usually a bad or missing body ground somewhere.

I've already explained that.

Does your car have air conditioning?