While the motor is at the day spa, I'd like to troubleshoot some electrical issues. The trouble is, when I reconnect the negative battery cable, nothing happens. No lights come on, no door chime, etc.

Do I need to jump, ground, or otherwise connect anything to get at least the chassis/dash/passenger compartment energized? I can only do so much in this state.

I should also add that the ignition switch doesn't seem to need the key in it to turn... Although despite that, everything electrical worked before I pulled the engine.



EDIT: The below heater blower issue is resolved, the relay powering the fan was burned to a crisp. See below pics for the carnage:






The issue I'm troubleshooting is that the heater/AC blower will not come on at any speed setting.

The previous owner claims to have proven the blower motor good by jumping temporarily the motor straight from the battery, and got airflow.

The resistor has continuity across the pins, i.e. the ones that are visibly connected are showing continuity/resistance. It doesn't seem to be the resistor.

The heater/ac control module panel is new/recently replaced, by the previous owner. The AC/Heater mode selector dial switch has continuity across all 3 pins/blades in the modes that involve the A/C compressor, and across only the two dark wires' pins/blades when in just fan mode. This indicates to me that the switch/dial is good. Where do the black/dark wires go to, and what is the next step to diagnose the problem?

I've read that the blower motor can have a bad ground sometimes, is that referring to the black wire on the plug accessible under the hood, or is it (poorly) grounded inside its sarcophagus,and I'll have to cut it out just to see if that ground is bad?


Thanks in advance.

 

Ok, so the pin to the motor on the heater fan relay is burned. That answers that.

But now, I'm just confused as to why I have no voltage anywhere other than at the battery.



I get voltage across both the starter and alternator cables, and at the connector that goes to the ABS/Driver's Side.

I don't get voltage anywhere on the driver's side, even at the below connector on the ABS module, which I DO get continuity to from the other half of the connector at the battery. (See above photo.)



There's a fusible link just after the connector at the battery, but I get continuity through it... Wouldn't that mean that it's good?

 

is the ignition turned on ? did you check the fuses Under the hood and inside ?

 

Does the ignition need to be on to get voltage there? I'll try it, but I'm not getting ANYTHING, anytime. cranking, on, ACC, nothing. The alt wire and starter wire are both disconnected, (the motor is in the shop) and I don't see anything else. I suppose I could cut the red wire in the loom as it goes across the front behind the bumper and test there...

 

the motor is out of the truck?

 

I don't see any fuses under the hood, I only know of the panel behind the driver's door.

I guess the real question is: How does the harness/chassis get energized, through the one fusible-linked wire, or somewhere on the Alt?

 

Yes, very. Troubleshooting electrical while it's getting machined.

 

So am I nuts for trying to do this without the motor in the truck? No voltage anywhere just seems bad...

 

check that your battery is properly grounded to the frame... normally it goes to the engine then the frame...via a ground strap.. if your engine is out.. no ground.