As I wrote in the title, My 99 died again and left me stranded. I've been blaming misc wiring problems for my weird issues but now I may have to do something about it.

When I turn the key, the starter will not engage. No bad fuses, I replaced the starter relay and had the starter checked out and it passed. I don't know what to start testing now. I have a voltmeter but I have no idea what to start testing from here. I'm horrible with troubleshooting these ls1's.

edit: Battery tested good, Starter tested good, replaced ignition relay, fixed BCM relay, fuses are good, replaced ignition switch, what NOW?

 

I did lots of searching on here, found out the body control module can cause what i'm experiencing. This makes sense, because someone else had said the ignition switch sends the signal to the ibcm, then to the guages, then engages the starter. (is that right?)

so I went outside to try to start it again and realized my guage lighting is not working, and my odometer is really really dim. No fuses have popped yet.

Can I test the ignition switch and body control module before buying a new one to troubleshoot? how?

 

Battery?

 

i should have said I already checked off the obvious

 

my car is doing the same thing except it actually died when I was driving. I think its got to be the body control module, or possibly the alternator. I noticed that one of the times, the voltage while running was staying at 12.0 constant. If I kept the RPM's up it would stay running but if I let it fall (which made shifting and braking a pain) it would die again. Im gonna pull the alternator tomorow, is there a way to test the BCM?

 

Check the actual ignition switch, the electrical part mounted about midway down the column. Very common for them to do this. It is also a standard gm switch as far as electrically. The only main difference is for the shifter interlock cable. Im running one in my V6 car from an 84 chevy pickup. Also check the plugs on it, mine were half melted, had to be cut off and spliced new ends on it. Plugs are also pretty much common GM. I cut mine out of a 90s astro van because none of the local dealers had any in stock and I needed the car goin.


To test it, if you have an extra switch handy or buy a new one (~$10) just unplug it from the old switch while still mounted, turn your key on so it'll register the vats, then use a small screwdriver to slide the "new" switch to on and start positions. You'll see how it works if your not familiar with it, not real hard to figure out.

 

cool, i've never touched the bcm or the ignition switch so its all foreign to me. And 10 bucks is great it just "sounded" like a 40-80 dollar part. I'm the type of guy that if its under 20 bucks and related to my problem, i'm replacing it even if it may be good. that way I have an extra. plus its the quick way to trouble shoot.

by the way, i love this site and you guys, seriously its the BIGGEST help to a guy like me. I have ZERO friends or family who know ANYTHING about cars. Being able to park it, post my issues to an experienced think tank, and get great collective knowledge is priceless.

 

Just noticed you had an M6 anyway, so your switch is the $10 one anyway. Only difference between it and the one for an auto is the shifter interlock.

 

you know, I bet your right and its the ignition switch for mine too. I had to take it apart when I converted to m6 and removed the interlock cable. Funny that the problem arises two years later though.

 

sooo it probably is the ignition switch. I checked the BCM for cracked soldier joints and tested the relay that has frequent soldier issues. That tall relay was engaging but the contacts weren't conducting. Then to make things more fun the electronics store said it would be 8+ weeks to get another, so I ghetto rigged it.



For all those out there with a weird window/dash/radio intermittent issue, this is probably the best fix for you! I removed the old relay, and went and bought a standard 30amp relay. The new larger one is 82 ohm and the tall original one is 90 ohms so there shouldn't be any signal strength troubles. The new relay is much larger and won't fit in the BCM case, so I drilled a hole and soldiered wires to all the leads to remotely mount it. Make sure if you do this to get the coil, common, norm open and norm close leads correct (i drew a diagram)




so now my top works again, and my dash lights aren't dim, but the car still won't start. Tomorrow I replace the ignition switch.

edit: I imagine all the other relays would be standard as well. To test a relay, un-soldier the relay you want to test. Get your voltmeter, set it to beep, and alligator clamp to normally open and common. take a 12v battery (a small test battery) and engage the coil by putting pos to one coil lead and neg to the other. the ohm meter will beep if the contacts are working. test normally closed by putting the meter to common and normally closed without the 12v battery attached.

 

That is awesome. I love the fix. We fix alot of honda computers and dodge dashes by soldering bad spots instead of spending $500-600. Our customers love us. I never fixed one of them we always replaced it. Might be something else to add.

 

NO GO ignition switch failed to solve my problem.. now what? Should I start with the neutral safety switch?

By the way, in the past when I had this no start problem, I would wait sometimes 30 seconds sometimes a day and it would start like magic. So it was an intermittent no start problem, until now.

 

Check your clutch switch on the clutch pedal. Disconnect it and put a jumper on it and try, just make sure your car isn't in gear.

 

OK Ghost, we both have '99 6 speeds with the same mysterious problem. Ive been stranded three times with the no start, after 15 min or so it starts fine and three different times where the car just died while driving only to come back on a 5-10 seconds later. My problems always seemed more prevalent at night. Well I tested the battery and Alternator, replaced ignition switch, checked clutch switch, resoldered the BCM, checked plugs at ignition and BCM, removed and cleaned all ground points on the car, added a new ground from the engine block to the frame, and from the battery to the frame, checked starter and wires, cleaned the MAF and throttle body and all associated sensors, replaced some vacume hose that looked dried out, checked for wire harness cuts or pinches, cleaned up my wiring for the alarm and radio and resealed a taillight that got some water in it. I found no blatantly obvious answers or problems along the way. I drove the car around for 2.5 hours last night and it ran very good the whole time and voltage never dropped below 13.2V. So I dont know if Im fixed but so far so good.

 

One of you guys should take your car to a real mechanic with real diagnostic tools and have them figure out what the problem is, and then come back and report here once it's fixed. Everyone whose problem is solved by the mechanic's results gets to chip in on the costs.