Tricky No-Start Condition!

[87CrownVic]

Hello all! Sadly, this is my first time back in some time, and sadly to ask for much needed help. My '79 LTD base model 302ci will not start. I am a professional automotive technician by trade, so this has been extremely frustrating on such a simple system. The vehicle started hard on a rainy night once after what I first thought was the starter grinding on the flex plate. Upon examination under the hood, I found this noise to be electrical popping/arching in the starter solenoid.This was after the car was shut off and would no restart. Since this point in time, I have loaded the parts cannon, replacing the starter solenoid, starter, solenoid-to-starter cable, negative battery cable, and charging/load testing the battery which is in decent health, holding 12.47 volts. I have cleaned/sanded and applied dielectric compound to every connector or connection I have touched. I have triangulated grounds by running dedicated grounds from the starter solenoid housing (where it mounts to the inner fender) to battery ground, as well as from the starter case (lower mounting hole) to battery ground. My problem is that I now don't even have the popping/arching noise from the solenoid. I now turn the key to the run position to see brightly illuminated engine and amperage lamps in the dash (normal) and turn the key to start to hear the solenoid click, but nothing else happens. when I let go of the key, the lights are very dim and the solenoid will not click again. However, if I turn the ignition off and back on again, everything is bright and happy again. Further diagnosis has found battery voltage present between the input and output polls of the starter solenoid when the ignition is off. If the solenoid-to-starter cable is disconnected, there is no continuity found. I have also found ground present on the solenoid-to-starter cable. This cable is brand new (I fabricated the damn thing myself, hammer crimped and soldered, connections covered in heat shrink tubing) and not in contact with ANYTHING other than the positive starter connection and the starter solenoid. To make matters worse, there is now a SECOND new starter and starter solenoid in the vehicle with the same thing happening. I thought there was a chance I might have overtightened the positive input to the starter, causing the connector to make internal contact with the case, thus causing the ground I was reading on the solenoid-to-starter cable. WTF IS GOING ON HERE!? Any thoughts or ideas are most appreciated.

[87CrownVic]

I have also turned the engine over by hand to make sure the damn thing isnt locked up...

[miamibob]

All the required Fuseable Links good??? Any other shorts????

[1990LTD]

where's the 12.47v? car off?

[87CrownVic]

All the required Fuseable Links good??? Any other shorts????

That's one thing I considered, but I don't see any the affect starting. The only fusible links I saw were for alternator/charging system wiring to and from battery (battery side of solenoid) and what I believe to be accessories. Please inform me of what fusible links affect the starter circuit so I can check them out.

[87CrownVic]

where's the 12.47v? car off?

I have 12.47V @ the battery, the battery side of the solenoid, and on the starter side of the solenoid (which I don't think should be there with key off). There is no voltage on the starter side of the solenoid when the solenoid-to-starter cable is disconnected. This is a big part of what makes my brain hurt...

[1990LTD]

do i have this right?


- battery voltage at starter side of fender relay with key off

- battery voltage at starter side of relay disappears with cable to the starter disconnected

I now turn the key to the run position to see brightly illuminated engine and amperage lamps in the dash (normal) and turn the key to start to hear the solenoid click, but nothing else happens. when I let go of the key, the lights are very dim and the solenoid will not click again. However, if I turn the ignition off and back on again, everything is bright and happy again. .

That makes me think part of the problem is in the ignition switch or circuit. I could be way off base.

[87CrownVic]

I thought about ignition switch concerns, but I honestly don't know how to properly diagnose them. I just dont understand how you can have battery voltage going through the solenoid while it is supposedly off and not have the starter turning over/ wires burning up. And yes, you have it correct.

[gadget73]

since the lights go dim after you turn the key to start, I'd guess the battery to solenoid cable is shot. When you put a load on it, it goes high resistance. They are often green and fuzzy inside. Give it a bend, if it crunches, its shot.

The battery voltage on the starter side of the solenoid with the starter not hooked up is probably feedback through the ignition switch. If the key was on when you checked it, thats not entirely impossible. The ignition system powers from the I terminal on the relay when the engine is cranking. When its not cranking, with modern digital voltmeters that present essentially no load, you can get a bit of leakage back through the diode and have it read voltage. Put any sort of load on there, and it should drop to zero volts.

[84merc951]

whats your volatage while your trying to crank it over? im thinking that you have a dead cell in the battery. if your soleniod is clicking while your trying to start i think to me thats a dead cell along with the lights going dim. even though the battery is showing 12 volts but thats without a load on it correct? hope this helps. matt

[84merc951]

my bad i just read that you load tested the battery already

[87CrownVic]

since the lights go dim after you turn the key to start, I'd guess the battery to solenoid cable is shot. When you put a load on it, it goes high resistance. They are often green and fuzzy inside. Give it a bend, if it crunches, its shot.

The battery voltage on the starter side of the solenoid with the starter not hooked up is probably feedback through the ignition switch. If the key was on when you checked it, thats not entirely impossible. The ignition system powers from the I terminal on the relay when the engine is cranking. When its not cranking, with modern digital voltmeters that present essentially no load, you can get a bit of leakage back through the diode and have it read voltage. Put any sort of load on there, and it should drop to zero volts.

I guess I should check this out, I counted it out without testing it because I replaced it around this time last year. Definately plausible though. Have to check it out tomorrow. Thank you guys for all the feedback, I'll report my findings then.

[jaywish]

What happens if you jump the solenoid?

[ford man]

My car will kind of do the same thing if the battery cables aren't tight enough on the terminals.

Also I might try a known good battery to rule it out...

Is the battery clean with shiny terminals?

[87CrownVic]

Well, the car starts and runs just fine. However, I'm still rather befudled. After finding continuity between the positive connection and case ground on my SECOND rebuilt chipanese taiwan garbage starter (one from napa and one from o'reily), I returned it and replaced it with a brand new unit from autozone of all places. The car started right up. I'd say there are some quality control issues going on, that would be the first and very hopefully the last time I have two back-to-back defective components... THANK YOU EVERYONE FOR YOUR INPUT AND IDEAS! I know I can always count on you guys, what a great community.