Gents, I am cross posting this from the '87 forum in case anyone here knows what's going on....

I have an '87 long bed with the carbureted 351 W motor. I am having an electrical problem when the truck sits in the sun all morning. When I go out to crank it up, I get nothing. All the dash lights (BATT, etc.) light up correctly. I hear an audible "click" under the hood, but no start.

Once the truck cools, starts on the first crank.

I assumed the starter solenoid (mounted to the inner passenger fender liner) was hanging up when it got hot (absorbing heat from the truck body) and the contacts were freezing.

I bought a new solenoid from Ford, wired it EXACTLY as the old: Positive cable from battery to furthest post from battery, all ignition/alternator wiring to that same post --- nearer post (to battery) is cable directly to starter, nothing else. Exiciter wire (red) from ignition to the small post on the top of the solenoid.

When I started the truck (which cranked first time) the starter hung up running. The truck would not turn off or disengage the starter until i pulled the negative cable from the battery.

Same thing happened with a GP Sorenson solenoid from Advance Auto, even when wired correctly.

The starter is less than six months old and has only the single wire connection from the solenoid. The battery is a year old. All other cables appear to be in good shape.

I replaced the actual electrical switch for the ignition that mounts to the steering column behind the dash (the key turning pushes a rod that makes the connections on this switch). All the connections and wires are tight.

I put the original solenoid back on the truck and everything works normally (starts, starter disengages, truck shuts off properly) until the truck sits overnight and gets hot in the sun again.

The only thing unusual is that the former ground cable from the battery looks like it was cut off near the oil pan and the end left in place on the ground bolt. A new cable was added and secured with a second nut which is very tight. It is also properly grounded to the frame about halfway down it's length with a bolt.

Any ideas on what is going on here? I am about ready to run this thing into the lake....

Axel F

 

The new solenoids are pretty much junk, I think you have figured that out. What I would do is get a voltmeter and do some testing.




When the truck fails to start, put the meter on point #3 and point #2 in the diagram below, and while watching the meter, try to start it.

If the voltage stays high when you hear the click, then we know the problem is downstream. If the voltage drops when you hear the click, then we know the problem is upstream.

 

Dave,

Thanks for the reply. Am I looking for voltage drop from 12V? I have ordered new cables for the run from the solenoid to battery and also a new ground cable. I know I'll have to remove the Alternator to really get to the grounding point on the block to do this job right. I figure I'll replace those cables while I'm in there...

Axel

 

Yes. You will normally see it drop down to 10, maybe 8 volts when it's cranking. But when it clicks and does nothing, you are looking for a drop from 12 down to almost zero. Even a very minor resistance in the cables will cause a huge drop when current (about 100 amps) starts flowing to the starter. That's why you have to test while you try to start it at the same time.

 

Thanks to Dave F and others who replied. Situation was resolved after doing a voltage drop test. The solenoid was bad, as were the NEW solenoids bought from Ford and Advance Auto.

A new solenoid from CarQuest did the trick.

I also recommend tightening the two nuts on both posts as tight as possible without breaking the posts. It appears a very tight connection helps secure all contacts.

Thanks again all!

Axel

 

Thanks to Axel and the others about this issue. We had (and still have) this problem. Our truck stopped running while driving, and also after a short stop in the heat. Last time (yesterday) Hugo had to run out of the truck while the starter wouldn't disengage and pull the cables out of the battery. We didn't know a battery could blow! Thanks VERY MUCH for that. Something that might help there is taking out the number 12 diode from the fuse box, in the engine compartment. It's the one on the top left corner if you are standing on the driver's side of the truck. Ours is a 95' Flareside.

But then, we don't see a solution to the problem (apart from running it into the lake and buying another one).

Is Axel still doing alright, or is this going to continue, like in the good old cartoons?

Cheers,


Gabriela (on behalf of Hugo)