5000TQ Avant Starting Problems

[Stephen Sherman]

Thanks Bob. I was aware of the solenoid acting as the high current relay
for the starter. But some cars have an additional relay that switches
the current to the solenoid as well. Not unlike headlight relays some
folks put in; Ford used such a relay to its starters on mid 80's
pickups. I was just curious if the 5000cs's used such a relay, and it
sounds like the answer is no.

I still don't think it's the battery. Not just because it is sorta new,
but because it has good voltage. It read 12.79v before starting attempts
at 10F just a few minutes ago. And it can run lights and accessories
just fine with no signs of dimming. I'd would think that the lights and
a few accessories  have about the same current draw as solenoid, or close.

"Playing around" with this switch theory I tried shooting some WD40 into
ignition switch, thinking that some of it may find its way to the switch
contacts. Whether coincidence or not, that seem to do the trick. The car
now starts just fine. Starter turns fast and engine starts. Tried it
several times and works every time now.

BTW, is there a clutch interlock switch for the starter on these cars?
Maybe some bad connections there (one place I have not checked)?

So I guess I will find out tomorrow AM after another cold night whether
the WD40 really did anything or not. But it would seem to suggest that
it isn't the battery, since that can run the starter just fine once the
starter runs. Might be the ignition switch. Or might be the switch in
the solenoid or some other wiring issue that just happen to start
working again at that time.

I hate mysteries, especially when you think you've solved them ;-)



Robert Myers wrote:
>
>
> The starter solenoid functions as a relay. The starter main load is 
> triggered by the solenoid and the ignition switch doesn't carry 
> anywhere even near the starter load. If the solenoid clicks then the 
> ignition switch is not the problem - at least not _this_ problem. It 
> sounds like the battery is weak. Less than two years old? Well, it 
> could be failing anyway. Or there could be a problem with the 
> alternator not providing sufficient voltage to fully charge the 
> battery on its own. Perhaps on of the diodes may have failed? Or the 
> brushes are badly worn or... You need 13.8 volts for a proper charge.  
> Try putting a charger on the battery for a couple of hours or 
> overnight and see the result. Betcha the engine will fire right up 
> then. Or once you get it fired up take the car to your local battery 
> shop and have then check the battery/alternator and see what they find.
>
> Bob
>
>
>