93 engine electrical problems

[cadteach]

93 Ranger, 4 cyl, engine hesitates (loses power) going over bumps. Check battery, check alternator, check connections. I find that I can reproduce the problem banging on the power distribution box. I open it up, check all terminals on the fuses and relays and diode in there. All looks good. Tapping the box still causes problems. Take it off, look at the wires entering, but I don't see any of the corrosion there, but wouldn't unless I start pulling terminals out one by one.

Any idea what I should look to do next? I sprayed contact cleaner in the box with everything pulled, put it back together ran fine for a short period. Today into work, the battery gauge starts fluctuating, back and forth, then drops to 8 volt and sticks. I get to work OK , but my battery is dead from running the lights and blower without being recharged. I jump it, it starts fine, is charging, test the alternator leads, they are giving out proper voltage (around 15 volts), battery passes test.

I'm not sure if it's possible to replace the power box under the hood, it looks like it would be a pain.

Any ideas?

 

[BOOYAHGRANDMA]

maybe the alternator is on the way out , have you had it checked? I understand that it is still some what charing the battery but maybe it is starting to go bad inside. You said you "reproduce the problem banging on the power reproduce the problem" have you checked to see if the ground thats by the power distribution box is nice and tight. I had something very similar happen to my truck and it turned out that the ground was not tight , every time i hit a big bump or went through water it would wack out on me. Check the grounds and the alternator , good luck....

 

[Bryan22]

could be a bad fuel pump relay. try swapping it with the ac relay and see what happens.

 

[94 lifted ranger]

since you said when you hit the power distubution box it would start acting up i would check all the relays first to make sure they were good and would turn on and were not making nosie when you shook them then i would check the wires going in and out the box for chafing split or frayed wires and then also try and blow out the box with compressed air thier could be something inside of the box shorting something out. then it never hurts to check all your grounds and make sure they have good a good connection.