Let me start by saying, swapping the engine for something better is not what's happening, so please don't suggest it. Recently, be positive terminal on my battery was grounded, causing it to spark something crazy. As a result, it will not crank. I have power to everything, but no crank at the starter. Knowing that I screwed it up, I appreciated to try and fix it. I replaced the starter, the ignition switch, along with the battery and all the cables. I checked/replaced any fuses, tested/replaced any relays, replaced circuit breaker and even bypassed the VATS Passkey with the proper resistors. Still no crank.

From what I was told and what I understand is simply that the starter isn't getting the signal or spark to turn over. The battery was the most recent thing done, but prior to that, the multimeter showed the battery power fluctuating. The battery was checked with a multimeter on numerous occasions while trying to fix this and from yesterday to today, it went from 12.4 to 15.5, all the way up.to 19, which led me to replace it.

I've looked for a starter relay, but haven't found an actual relay labeled for the starter. There is a fuse and slot 11 of the dash panel, that the Haynes repair manual calls a starter relay, but it was not blown. As for the ground issues, the block ground has two additional, small black wires with a white stripe, underneath the negative ground that did show signs of the connectors being burnt at the block ground location. I did attempt to try and Trace these wires back through the harness, but was unable to find the origin point.

The computer was taken out earlier today and we inspected the connectors as well as the boards for any signs of being burnt and didn't notice anything out of the ordinary. needless to say, I am at the creek without a paddle at this point and don't know where to turn now. Granted, I could have it towed to a mechanic and have them run a diagnostic. However, I'm not financially at that point of towing it there and back and paying for whatever happens at the shop. Plus, I have a little problem with other people working in my engine.

let me know if you have any questions that might help solve this issue. Any advice would be truly appreciated. thanks in advance for whatever help you can provide.

 

I take it you're not getting any switched 12v voltage at all at the starter itself when turning the key?

If not, do you have wiring diagrams for the car? If so, I'd start at square 1 (the key switch wiring assuming you've got power there) and start checking for voltage when turning the key to start. Keep moving down through each connector and component on that circuit until you find where you no longer have the voltage you should have when turning the key.

Thatll isolate which part has the issue, you can troubleshoot that part from there once you find out what it is.

 

There was power to the starter but it fluctuated consistently, which was the final piece that led to the battery replacement. Haven't checked it again with the new battery since trying to start it resulted in the same issue. It was suggested that the starter just isn't getting the signal from the ignition to turnover because each time ignition turns to run, the relay clicks, but that's all. I did remove the relay box next to the battery, with the working relay, and noticed that the plate underneath, that provides the power, was charred. I did check each relay and fuse and non-issue. Would the charring prevent any action? I didn't think so, so I didn't reeplace the box

 

Oh and yes I do have the wiring one lines in the Haynes manual.

 

So to be clear, you had good constant power to the constant starter terminal, but the switched power terminal wasn't getting 12 volts consistently?

If the switched terminal power was the issue, I'd do what I mentioned above- go and turn the key to start each time you probe for power at each component/ connector down stream in that circuit (following your diagram) until you find out where you lose your strong 12 volt power signal. I like to start at the beginning of the circuit (in this case I'd start at the ignition switch wires under the dash as thats where the switched starter power initiates) and keep confirming good at each connection and component until it changes to bad at the output side of a component or connector. That tells you exactly which part in the circuit has the issue.

Once you locate the component or connector where you lose your strong signal, you can then troubleshoot that specific part. But you need to isolate what component is causing the issue before you can troubleshoot it.


Honestly, the battery reading 19 volts worries me too as I'm not even sure how thats possible. I get you replaced it, I'm just worried voltage that high might be fried other components. Fingers crossed that once you get the starter issue fixed that this thing actually runs.

 

Thanks for the input. SERIOUSLY! I've been banging my head trying to figure which direction to go with this. One more thing though. I'm fairly wet behind the ears when it comes to the multimeter. Not to mention, I've never really messed with the electrical, more intimidated I'd say, so I don't know a lot about it.

From what I can tell though, from the one line schematics and hands on, is that the signal wire is the one I'd need to trace from the ignition switch down to the starter. Am I correct on that?

Also, I still can't figure out why VOLTS is still lit on the instrument panel. Someone asked if I had tested the voltage regulator, but that's in the alternator and I don't think it would play a role in this. Unless I'm confused. Just trying to cover all my bases here so I can try and check/replace as much as possible in one day really. Thanks again for the advice though! Oh and thought I'd share a pic of what the battery read before I swapped it. Had us a little concerned at that point.

 

So the starter solenoid should have 3 terminals if I remember right (I'm a bit fuzzy as I haven't had a 3100 in my 96 for probably 15 years now).

There should be a big ground lug, a big power lug (constant), and a small lug for switched power. Given you just replaced the big cables, I'm assuming you've got a good ground and good constant power to the starter.

If the small switched lug is still finicky on power when you're trying to start it, then that's a good first place to start.

You are exactly right though, the ignition switch would be pulling power from a hot wire coming into it and sending that to this switched starter wire. When they key is turned to start, you should have a solid +12 on that outgoing starter wire at the ignition harness.

The difficulty is that it doesn't run directly to that terminal on the starter, it runs through other stuff on its way there so you're trying to figure out exactly which place you go from having a clean +12 signal on this circuit to anything else (no output, less than 12 volts, finicky 12 v, etc). Thatll tell you the first component you'll need to troubleshoot.


In terms of the volts light, I wouldnt worry about it. That light will come on when the ignition is in run, but it doesn't see elevated alternator voltage. Given you can't even get it to turn over, you don't know for sure if that'll go away when you finally get the engine started.

 

So, I started at the ignition switch and followed it down and at the park/neutral switch, I found that one of the black and white wires that had burnt, went into that switch. I went ahead and pulled it and the underside showed that it had been charred at the wires entering the switch. So I'll replace that and that should be the final piece, since everything else has been fixed or replaced. I'll post any update I get too. Here's a pic of the charred switch.

 

Ouch! That sure caused an awful lot of damage for something some simple.

Fingers crossed this is your last hurdle!

 

Forgot to jump back on here with an update. Long story short, no dice. The neutral safety switch replacement didn't fix the no crank issue. Since the theft deterrent relay and module are next in line, I did attempt to bypass the VATS at the ignition wiring, using the equivalent resistance (=/- 1-2%) that the key has, but that didn't work either. Still no crank.

Before attempting anything further, I figured I would breakdown and get a scanner that could read the codes and got an INNOVA 3120rs. After purchasing it and waiting for the arrival, I then found out it couldn't read the codes, since I have the OBD1.5 hybrid headache. OBD1 system with and OBD2 connector, except no A and B to jumper. Only A and M, limiting my options further.

I would rather just replace or remove the theft deterrent module, but they're virtually impossible to find for this car, if at all. Either way, that's where I'm at now. I also went back thru the relays and fuses to make sure nothing shorted since and was good. I'm wondering now if pulling a theft deterrent module from the pull yard and getting a replacement key and tumbler to relearn, might be the route to go, since I can't find as replacement outside of the dealership. If this doesn't work though, I don't really know where to turn. And for those reading this instead of starting from the beginning, here's the list of items already replaced after attempting to reconnect the positive cable to the battery that had the negative already connected.

Replaced battery
Replaced pos and grd battery cables
Replaced starter
Replaced driver side, relay box, circuit breaker
Replaced ignition switch
Replaced neutral safety switch
Cleaned block ground location (2 blk/wht wires showed burnt, leading to neutral switch replacement)
Attempted resistor bypass to VATS on ignition key wires

...and STILL need help!!