1990 Ford F-100 starting/battery

WILLDABEAST

MEMBER
1990 FORD F-100
5.0L
V8
2WD
AUTOMATIC
200,000 MILES

When I jump my truck the power comes on, but there is a crackling noise close to the dashboard in the engine area and when I turn the key to try and start it, it clicks once and the power goes out. I then reset the jumper cables and the power comes on again and repeats when I try to restart it.

1 Reply

CARADIODOC

MECHANIC
33,874 POSTS

This is typical of bad battery cable connection. To find this you either need to get it to act up and keep it that way, or turn on the head lights and perhaps the heater fan so current is trying to flow, then measure the voltage right on the battery's posts. You should find close to 12.6 volts.

Next, move one meter probe from the positive post to the positive cable clamp. The voltage should be exactly the same. Now move the negative probe from the post to that cable clamp. Again, the voltage should be the same. You're looking for the place where the voltage drops. That will be the mechanical connection that needs to be cleaned and tightened.