[Idol]

Voltage goes down to 4-5 V so ECU doesn't work.
Starter spin but slowly.
It happened after head gaskets were changed.
What is a usual reason?
Thanks.

 

[Jetdoc]

Bad battery or poor connections. Should only drop to around 10-11v. A battery with a "dead cell" will drop quickly like you stated when under a load.

 

[Team LR]

yea it sounds like a bad battery or not charging properly

 

[DrDave]

Just a shot in the dark but how about a ground wire not connected?

Dave