Did you do a drop of voltage test on your starter circuit ???for that, you'll need a digital voltmeter. It is one way to find out where you might have a high resistance in the stater circuit. Once you have the problem you descripted, can you crank the starter directly by putting a jumper at the solenoid to crank the starter ???
If you can crank your starter directly by jumping the solenoid then you'll know that something is wrong on your relay circuit (solenoid side).
You'll also need a wiring diagram for your car. It is amazing how a little added resistance in the circuit can throw the all system off balance.
Because remenber that you beginning with 12 V, a high resitance can drop that 12 V to a 10 V and that itself is enough to keep a component from operating properly.
Good luck and patience.
Phil.
Keep us posted.
So far, i always find electrical problems on my cars. Keep my fingers cross.

Gary, what filou said is why I totally replaced the yellow wire. The factory wire had so high resistance it would not carry the voltage for the circuit. It would test fine for continuity, but its resistance values were crap, so I ran a new yellow wire, somewhat of a pain... but it has not failed to crank since I did it back in 98 or 99.

bump....any new revelations here, Gary ???

--Wil

Will, thanks for asking. The delema continues, although I have not driven the car in about 2 months- I am recovering from surgery- different story and I will be fine. I ran an 8gauge wire, fused with a 30amp fuse, from the positive of the battery to the starter as I am starting to suspect it may be the main lead itself. As expected the car ran fine for about 2 months, then didn't start- at this point the 30amp fuse was blown on the aux line. I put in another fuse- car now started, but of course the fuse in the 2nd parallel line blew, but the car was running great. Here is my thought process- see if this makes sense to anyone else. If the main lead from the battery to the starter was functioning normally, I would never pull 30 amps through the smaller additional lead. When the car will not start normally, the additional lead is pulling over 30 amps, but with that amperage will turn over the starter. Of course that only happened once, and now the car is starting normally again. I have about 2 more weeks before I can work on the car again, my plan was to replace the cable from the battery to the starter and see if that works. Any other thoughts here?

BTW, when the starter will not turn from the key, it will turn if I jump directly to the starter. The aux starter switch, which doesn't always work bypasses the yellow wire and ignition switch, so I don't think they are the problem. I am almost afraid to fix this problem, because it has kept other problems from cropping up.

Gary:
Go back to 89911's comments...the next time it happens....have someone slightly jiggle the main red power line on the + post of the battery.

My 85 Carrera....fully up-to-snuff on all things electrical..just did this after a longish, slow, hot run. It came to life only after I jiggled the red wire. Never happened since...but you never know. My car has fresh ground straps, additonal ground straps, cleaned connections, new fuses, dielectric grease on connections, new Optima battery on a chipped trickle charger, etc, etc.

Did you ever do as 89911 suggested ??

At some point, it can also be bad soldered joints within the DME motherboard, or the small round connector under the dash...the size of a dime. A friend's car wouldn't start and we had a hard time figuring this out until we found this plug had come un-done. Should be a hard press fit too.

These are options offered only after the points you had raised earlier were addressed ( DME relay, yellow wire, etc).

Wil

starting problem
 

i concur with 89911 i had the same problem last year,, batter the whole routine and found out that the positive connector in the wire itself was green with corrussion,,, i replaced both the positive and negative connectors and the car starts easily

gary

The battery environment can be very corrosive. I replaced my battery ground cable for a corrosion problem as described by 89911. It cured my intermittent no-crank problem.

:)

I have tried moving the cable at the battery- no luck. The one time it was at the shop and dead, my mechnics first voltage reading at the starter was low, when he went to check his connection all of a sudden the voltage reading was ok, and the starter worked normally. It sounds like it is at the starter side. I don't have enough slack to replace the connector, is there a way to splice this type of cable? BTW all the ground straps, at the battery and tranny have been replaced during this hunt, no change.

Gary:
I think we're getting close by your latest desrciption...at least close-er.

"When he went and checked the connections"...is v. much like jiggling the wires at the battery. I also have new ground cable at the battery ( the pole locations are different on Optima bateries and required this anyway).....so when this happened to me the *one time*....a gentle nudge of the red positive cable allowed the starter to work...and I mean the gentlest of touches on the big red cable. I haven't yet taken that cable apart to see if there is evidence of green corrosion, or a weird break in the line that makes intermittant contact... but if the cable is in any way suspect, and if there is enough slack length ( I think there is), I might trim this back an re-attach, and see where we go from here.

My point? Don't dismiss this possibility out of hand......we're really scratching for nuances.....

Wil

gary

when you said you jumped directly to the starter, did you do it across the selonoid or with jumper cables?

Jumper cables directly to the starter. I can't crawl under my car for a couple of more weeks- I have a 10" incision that is healing- but if my memory serves me right, I don't have enough slack in the existing cable to change the connector, but I'll check. That was why I was going to run another cable from the battery+ to the starter. Then I'll wait 2 months, because the problem is soooooo intermittent. Again, I am almost afraid to fix this problem, as it has kept other problems from cropping up!

mmm, have you tried jumping directly across the terminal (as previously suggested by someone) avoiding the selonoid and utilising the main cables?

if that doesnt work it sounds like the main cable.

Could someone tell me the route of this "yellow wire"? I'm having intermittent no start probs on my 88 and this may be important. I also noticed the large, short yellow wire coming out of the ignition switch has been spliced for an alarm I removed some time ago. This short wire, along with about 5 others, goes to a connector that plugs into a small receptacle in the dash. I reconnected these wires and then soldered them hoping that my problem was due to a poor connection not allowing the current to get to the starter. I assume the yellow wire is the one that continues on from this poing back to the starter.
TIA

That is the one, most of the aftermarket alarm installers go fo it when the install the alarm. That is the ignition circuit wire that goes to the solenoid. That is the one I had to replaced, have not been bothered with the no crank problems since. I just left the old one where it was just removed it from solenoid, and ran the new one from the ign. switch back to the solenoid, it has been so long ago, without looking at it, I really can't remember how I have it running from point A to point B.

Look like it has been a long time of this thread but I am having the same problem now (exact same problem as gchappel).

Thanks wil for bringing this post up.

gchappel,
Have you found the real problem?
The main cable to the battery+ or the yellow wire to the ignition key?
Do you know the safest path the re-run the wire from the starter up to the front?
What wire size is the best for the replacement wire?
Thank you.

I ran a large gauge wire directly from the battery to the starter, I forget the gauge- it was the battery cable they sell at the local auto parts store. I ran it across the front trunk, down into the passenger compartment through the hole for a right steering column. I drilled a hole in the rear floor, put a rubber gasket in it- and the wire exits about 6" from the starter. Yes it is fused. I haven't had a problem since- but I may have just jinxed myself. I actually had forgotten about it:) I don't know if this was the safest route to the starter- but it was pretty easy. My thought process was to keep the cable as safe as possible-- with this run it only runs through one hole. I didn't want to run it under the car as my car is pretty low and was afraid of damage to the cable itself.
Gary

So basically you are replacing the main power wire for the starter, not the yellow ignition key wire, right?
By any chance you can remember what kind of rate of the fuse you are using?

Reading your problem description and testing procedure, I remember you mentioned the test fuse you were using were blowned and the wire got real hot. That seem to me that some component got shorted. How did you fix/repair that?

Thanks gchappel.

To "test" my theory I had run a small- 12G or so wire with a 30A fuse from the battery to the starter. My thought process was if the main power lead was normal, the starter would not pull 30A through the additional lead. I checked the breaker every couple of days and it was fine. One day the car would not start, and that breaker had blown. I reset the breaker- car started fine, but the breaker blew again. I know 30A is not enough to run the starter- but it was enough to give it a "kick". Over a couple of months this repeated itself a couple of times. That is when I used a large battery cable- and have had no problems since. I forget the fuse size- car is up in my race garage. I know I got it from our high end audio guru- it is over 100A. Again, I am not sure that this was the issue, but the car has started ever since.
Gary

A few thoughts on this problem.

The main lead is not likely to be broken and problems would be where the connections are attached to both ends. Check these with a resistance meter between the terminals and the cable alongside the lug.

The yellow wire comes from the ignnition switch to a plug under the dash which carries it through into the luggage compartment where you will find the other side of the plug.

from there it gets to the main wire loom and back to the engine compartment to the 14 pin connector under the black plastic cover, drivers side. from there it goes across the engine to the starter solenoid.

I once had an intermittent problem which was caused by the under dash plug not being seated properly. An easy fix.