kevdog442

Would a bad ignition switch cause my alt to not charge. Sometimes when I turn the ignition to "on" (first position) the gen and hot light do not come on as they should. In fact, when they do come on sometimes dim and sometimes bright. The gen light always comes on when I turn it back to acc. In either case when I start the car, it's not charging.
68 cutlass

MDchanic

It would probably cause accessories not to work as well if the switch were bad.

You need to check continuity through the charging circuit. It may just be a dirty or loose connection.

- Eric

kevdog442

You mean like the heater blower? Because it's not working now but fuses are all good. Well, except for the inst. can't seem to get power there. But really don't understand that because sometimes if I jiggle the switch, the lights come on.

MDchanic

Power windows, power seat, rear window defogger, heater blower, cruise control, power antenna, radio, and windshield wipers.

And which switch are you jiggling?

- Eric

kevdog442

Ignition switch, It's got some play in it.

oldcutlass

IMHO, you may need to get your ign switch straightened out before continuing on trouble shooting.

MDchanic

Yup.

- Eric

kevdog442

Yes I agree with that, was going to do it anyway, but was just hoping it would fix the charging issue. I just can't make out on the schematics the charging circuit.

kevdog442

All of my accessories work now, the heater was just unplugged from the dash switch. And it seems that the regulator gets voltage from the ign. switch and there is power at the regulator. Yeah, the switch has some play but it's working
So why are my GEN and HOT lights not coming on when I turn the key on?
Fuses are good bulbs are good

MDchanic

Do your oil pressure light and your fuel gauge work?

- Eric

kevdog442

When I turn the key there are no warning lights,(except sometimes briefly if I wiggle the key and then usually dim or go out again). If I turn the key to acc (ccw) then the Gen light comes on and stays on.

MDchanic

Fuel gauge?

kevdog442

Doesn't appear to be working says about 1/2 tank but doesn't move.

Also when the starter is cranking the Hot light is on but that's all.

MDchanic

Well, there goes my theory.

If the HOT light comes on when you crank, the instruments feed is hot and working.

Next place to check: Are the bulbs burned out?

- Eric

Octania

It's quite common for the gage pod circuit board pins to break off or come loose and work intermittently or not at all- fuel gage, etc.

For a GEN lite to work on ACC but not ON [engine not running] seems like trouble elsewhere though.

The HOT light should come on only if the wire at the temp sensor is grounded [like if engine is hot or you are grounding it for test purposes], or when ign sw is in the START position, to prove the lamp.

kevdog442

I know things can go bad at any time, but being logical like I am I tend to start looking at things I last messed with when there's a problem. So I should note that this all started when I replaced the engine. Nothing inside the car was messed with except the shifter, everything was working fine before. (I had a starting issue first ,there was a thread, which turned out to be this charging problem and The battery kept draining). All wiring was carefully set aside reinstalled the same way.

kevdog442

Well except for the temperature sender, I have a mechanical guage so I didn't hook it up, but when I did, my dash lights (gen/oil etc.) and fuel guage started working. Maybe it grounded the circuit?