intermittent car no charging, lack of voltage issues

kwikcoupe

Registered User
so Ive got as 90 Sc and its been a good car but starting to show it age. I fixed the camshaft sensor, reapplied thermal paste to the DIS and now its has this wierd issue with the charging system? The car works great but every now and then 2nd time today in 6 months. You be driving down the road and the radio will start to cut off power here and there, the car gradually acts like its running battery alone and runs totally 100% dead in a matter of 3-5 minutes.

The last time it did it I towed it home, replaced the battery connectors as the possitive didnt look 100%, the alernator checked out on the bench and the battery did also. Cars workewd great. Today same thing only I called the wrecker and walked the remaining 3 blocks to work. I decide its friday and Im too aggitated to work and walk back down to the car, figure why not try and see what it does. It starts and acts normal. When I left it it acted dead dead and now it starts runs drove it 30 minutes home and everythings ok so Its obviously something heating up causeing a high resistance or ???

If you guys know anything please feel free. I dont have the cash to randomly toss parts at it and most fixes have seemed expensive but been really cheap in the long run. The car usually sits for extended periods say a few weeks then gets used for a while and sits again. The battery is new, alternator was replaced a few months ago, same issue as this, I checked the little 6 inch ground strap from the battery to chassis but cannot find any others. There is a small ground wire that runs in the engine harness and has a connector to the left of the SC top and its bare and looks bad, what does this go to and can I reground it without tearing out the harness? Thanks for the help now back to work for me lets hope the car keeps ruinning. Mike
 
Mike:

You can check quite a few things without spending more than some of your time - start by removing the trim panels between the steering column and the dash (3 Phillips-head screws that come out from the bottom). Look down on the right side of the steering column to locate the actual ignition switch (not the key cylinder). See if this large switch is coming apart...try to start the car and if it hesitates, wiggle the connector and see if it improves. You might have to replace this switch...this is a fairly common problem.

Also, check the ground strap from the lower left/front side of the engine over to the body...if the connection at the body looks green or corroded in any way, remove the bolt and wire brush the connector and the area where it connects to the body and reassemble.

Get a flashlight and examine the connection of the large wire on the back of the alternator. Make sure it isn't corroded or loose. Do the same for all the wires you can see that connect to the solenoid near the battery.

Be sure both battery terminals are clean and tight. It is better to use molded cables with clamps - not clamps that bolt onto the end of the cables. Resist the urge to save money here :)

From your description, it sounds like:
1.) The alternator is going bad - again. Seems other owners find that various rebuilds don't last very long. You might need to have it tested on the car...both amps and volts. Does the battery light in the dash come on at all? Turn the headlights on and try to start the car - do they dim or stay the same?
...or...
2.) The ignition system has one or more issues. Does the tachometer bounce around?

>There is a small ground wire that runs in the engine harness and has a connector to the left of the SC top

That wire is part of the shielding for the electronic ignition. It needs to be intact - don't just ground it. You might need to find a better harness if you can't repair it.

Good luck!

Ken
 
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the tach doesnt bounce around too much or at all when running. Ill check the other symptom you described. The battery light doesnt come on or anything on the dash that would show a problem symptom. Ill pull the battery and play witht he cables I can get to. If the alternator went bad wouldnt it pull a check engine light or anything. I know the bulb is good at startup.

Thansk and Ill post an update in a few minutes as to what Ive found.
 
The 'Battery' light comes on when the alternator isn't putting out enough current to push a charge to the battery - the light basically means that current is flowing out of the battery instead of in. There are no other specific lights that would come on to indicate an alternator issue.
 
well the battery terminals are good, clean and tight as they were before the issue. The alternator wire is tight but I need to charge the battery before I can limp the car down to have it load tested.

The ignition switch is in good condition. I tried to wiggle it around but no change.

I did find evidance of an aftermarket alarm vias the crush type crimp connectors on the starter kill. I removed, inspected and repaired with high quality tape a few wraps. The insulation was damaged but the conductor appeared to be in good condition soo The tape is just for further insulation.

The wire that goes from the battery to the solenoid, on the solenoid side has a tight 90 degree bend in it to avoid the windshield washer eeservior. Is this normal? The ground strap from the battery is toight to the block but I cnnot see the connection. There is a biuldup or grease and oil and otherwise the connection seems tight in all ways. I cant imagine soil debris getting under the connection?

Is the harness shield wire supposed to be bare or is there supposed to be a black/purple insulation on it. I may cut the splice connector off of iot and install a butt splice in better shape.

So Im waiting on a battery to charge for an alternator test. Is there anything else it may be. A relay, solenoid?
 
When replacing the alternator or battery, it is important to NOT use the alternator to charge a weak battery. Relying on the alternator for this job can overheat and kill it. Always use a battery charger to pump up the battery first.

>The wire that goes from the battery to the solenoid, on the solenoid side has a tight 90 degree bend in it to avoid the windshield washer eeservior. Is this normal?

Should not be an issue.

>The ground strap from the battery is toight to the block but I cnnot see the connection. There is a biuldup or grease and oil and otherwise the connection seems tight in all ways. I cant imagine soil debris getting under the connection?


Look at the attached photo....check the strap on the passenger side of the block, front, where it goes over to the body. Note that any electrical connection can have hidden corrosion. Sometimes you must remove and clean or replace before it can be considered reliable.

>Is the harness shield wire supposed to be bare or is there supposed to be a black/purple insulation on it. I may cut the splice connector off of iot and install a butt splice in better shape.

This is a ground path that is specifically shielded to prohibit EMI (electro-magnetic interference). Unless you know how to comprehensively repair such a circuit, the only way to make a reliable repair is by replacement with a known good harness.

>Is there anything else it may be. A relay, solenoid?

There are several relays - do you know how to check resistance, etc.? Do you have any wiring diagrams? Start with the power control box by the battery. Check the volts & resistance across the solenoid.

These cars have very complex electrical systems/components/connections/wiring etc. They are reaching the age were these can become degraded to the point of needing significant troubleshooting before they respond. Of course, you may have a simple problem, but again, these cars are known for having issues that can be a pain to find & fix.

An example is the power control box next to the battery - this box has wires that come in from below, and you may need to pull it loose and expose the wires underneath before you find a problem...wires sometimes corrode, which causes resistance and overheating. If this happens, the wires/connectors can melt and/or pull away from the fuses/relays inside the box and cause multiple issues - they can also short out with adjacent wires/connectors. Until these types of components are checked, it can be difficult to eliminate them and find the real problem. The computer itself can be suffering from shorts or bad grounds...also the IRCM, behind the passenger side headlight. You need wiring diagrams and proper tools along with patience and luck if it gets to this point.
 

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Ive got the alternator torn out and the battery charging. The napa battery was maybe 3 days old and its the largest CCA I could find. I think the alternator is the issue at this point. I sure hope so. I live in a nice area and nobody likes seeing a towtruck outside there house. My old battery was a redtop optima that never worked very well with this car. It may not have been 100% when I replaced the alternator but Im sdure it was at least 80 or so maybe. I did get the schucks alternator. When the ford tech says his were rebiulds I figured whats the difference if the same guy rebiulds them all right? Thanks for your help and if you want to stop by and make my engine bay looks as neat and tidy as yours in the picture Id be ok with that anytime.
 
Pic not of my car - I have a black (35th) SC. Don't recall who shared that photo, but I hate 'em :)
 
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Is what im getting
 
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