You used the jumper cables and bridged the power and got nothing. You did the same worth the battery ground to the starter. Unless I didn't explain it good enough. Jumper the starter relay and check the power at the starter wire
Que I really appreciate your help with this. Here's what I did today; I took the starter off and "bench tested" it by hooking battery positive to starter terminal and battery negative to starter case. Then, with a screwdriver I jumped from the hot starter terminal to the smaller terminal post on the starter. It worked fine.
Next, I re-installed the starter and basically did the same thing (hot battery to hot starter, negative battery to starter case) and turned the key. She fired up! Then, to test the battery cables, I took off the hot jumper cable but left the negative on. Again, it fired up. [This may be where I misunderstood you earlier, Que]
Conclusion, bad ground. I undid the firewall ground and engine block ground and scrubbed all the connections shiny. Put it all back as it should be and it starts as normal.
Whether it's all a coincidence or not remains to be seen, but I do know it wasn't working this morning when I began and now it does, so I'll consider it a success for now.
Well, so here we are again. It worked fine for me the past several weeks, but the symptoms returned this week. I thought maybe the starter was going bad, but each time I pull it and test it with jumper cables, it kicks on just fine. Whenever it's installed, I still can't get it to do anything when I jump the hot starter terminal and the switch terminal. I have checked all of my continuity to the grounds and I get zero resistance.
Tonight, I took my multimeter and, with the starter off of the vehicle, I tested from the small stater terminal to ground and had my wife turn the key. I get zero voltage reading. I have checked continuity from the relay to the starter terminal and from the battery terminal to the relay, and both were okay. I've swapped starter relays and still get nothing.
I am pretty much down to the ignition switch. That pretty much has to be it, right? Am I missing anything else? The only think that keeps me from being 100% confident is that when I have everything hooked up, I hear a click when I turn the key...
Ok, sorry Que, we've had a death in our family and we've been trying to figure out the best way for us to get back to Indiana this weekend.
However, I did get a chance to work on this issue some. I replaced the starter switch (not too bad of a job) that didn't seem to help. I checked the voltage at the starter terminal (small/switch) before I put everything back together and I got 12V. So, I put it all back together, checked for 12V one last time before hooking up the starter and everything was fine (feeling pretty optimistic at this point). I reconnected the starter and hallelujah she starts to turn over. I try a second time and....nothing....eff.
SOOOO, I'm back to checking voltages and continuity. Based on the diagram posted earlier for the starter relay, I should have continuity from the 30 pin slot (relay removed) to the small starter terminal, and I do....with the positive battery cable unhooked. Here is the thing that has me stumped...I lose continuity from the 30 pin slot to the starter when I hook up the positive battery cable. Why in the world would that be? I am basically measuring the continuity of a piece of wire that, without the relay, is independent from the battery terminals and electrical circuit altogether.
Hopefully someone was able to follow all of that rambling and has something that can help me out, because I am truly stumped at this point.
Correction, it is 87 that goes to the starter, 30 goes to the positive battery. I just checked again, I have continuity from the battery to relay slot 30 and from relay slot 87 to the starter. I also read 12 volts from the battery to the relay slot 30.
When I bridge slots 87 and 30 though, I get nothing from the starter. How is this not putting 12 volts to the starter?? So frustrated.
Fair enough. Regarding my last post though. What am I losing between the 87 pin and the starter when I jump the hot wire (30 pin)? I guess, to me, it makes sense that if I have 12 volts at the 30 pin, and continuity (with the battery unhooked) from the 87 pin to the starter, when jumping between 30 and 87 I should have 12 volts at the starter. I am getting nothing...
HD. I am sorry to hear about your loss. I wish you the best. Since you have the no start it is easy to test. I want to talk you through it but if you can work with me we can figure it out.
A couple things on using the meter.
1) resistance should alway be measured with the battery disconnected
2) always verify the voltage reading of a meter by checking across the battery before you start reading.
3) always try and refrence ground to the same point ground would be refrenced for the voltage you are reading (Especially important for sensors) then if nothing refrence a good chasis ground
You have no voltage at the small wire but voltage on the larger starter wire correct?
Bridge the smaller and larger wire with a screw driver or use the jumper cable and put power to the small terminal on the starter and it should crank. If it does then use a small chunk of wire from the battery positive and put power to pin 87 and see if it cranks. Try not to mess with the starter or the wiring right now since the issue is intermittant and you have the issue you dont want it to "fix" itself until you know what is going on.
Thanks, Que. We will actually start heading back to Indiana some time this evening, so I'm afraid I will not have too much time to work on the Jeep this weekend. Regarding your most recent post though, if I bridge the large and small terminals on the starter, I get nothing but a nice hot spark. When I take the starter off and use jumper cables however (battery negative to starter case and battery positive to larger starter terminal, then jump with screwdriver), it works just fine.
Thanks for the meter tips, too. I've been wanting one for awhile now and just picked this one up, but I will be the first to admit electricity is not my forte (I'm a mechanical engineer by trade). What I did to measure the voltage to the fuse box was test the 30 pin on the relay and ground on the negative battery cable. I get a good 12 volts there.
If you see a arc when you are shorting then you are either dealing with not enough current....bad cable or a bad starter. Use the jumper cables and jumper ground strait to the case and then start. Do the same with the hot. It should crank over. If it does then bad wire if it doesn't bad starter. Did you try the hammer trick to see if it would start?
I will try this again just to be sure, but I seem to remember that when I did this before it didn't work. Which is what led me to pull the starter, only to be surprised that it kicked on when I bench tested it (jumper cables with starter on the ground as described above). In fact, every time I have tested it on the floor it has worked.