Sorry for being so persistent and . . . uneducated . .but can I run my test light or meter between the s terminal on the solenoid to ground and then from the r terminal to ground to see if I have any current draw from my solenoid with the key off? the value should be zero . . correct?

 

There should be no voltage present at either the Start or the Run terminal when the ignition switch is in the OFF position. So, having your test light configured as you described should not cause it to illuminate.

Live well,

SJW

 

The test light didn't come on so .. . must be an small internal short in the wiring harness .. I"ve looked at everything else.

 

I don't recall the details of your other thread, but if the parasitic current is low, a short circuit in the wiring harness that would be the cause would have to be a high-resistance short between wires in the harness, or between a wire and chassis ground.

A low-resistance short would be letting all of the smoke out of the wire(s), and you'd have no trouble locating it. Unless the car went up in flames, of course.

Live well,

SJW

 

Yes its only a 90mA draw . . someone suggested thermal imaging but I am skeptical it could pinpoint that inside a wiring harness. I don't believe it is a short to ground but rather between wires in the harness.

 

testing the way you describe, won’t tell you if your draw is in the solenoid, unless you disconnect the red wire going up to the horn relay from the solenoid, leaving only the solenoid in the circuit. If you don’t disconnect that wire you’ll be reading the same electrical point as on the horn relay and therefore won’t eliminate anything.

 

Thanks 65GGvert and SJW . . I appreciate all your expertise . . I think my only option now is to try the thermal imaging. I have gotten into the habit of using my new battery cutoff switch so finding this draw is of less immediate concern although I am frustrated by both my lack of understanding and my inability to solve what on the face of it should be a relatively simple problem.

 

Highly sensitive thermal imaging might be able to detect where this current is flowing, but you should be able to get there without such equipment.

I highly doubt the solenoid is the problem, because its pull-in and hold-in coils should be isolated from +DC when the key is in the OFF position. You can verify this by measuring for DC voltage -- using a DMM rather than a test light -- between the S terminal and chassis ground, and between the R terminal and chassis ground. Alternatively, you can disconnect the ring terminals from the S and R posts on the solenoid to isolate the windings.

Presuming the solenoid coils are truly isolated as they should be with the key OFF, this would leave +DC present only at the large post to which the battery + cable is connected to the high-current contactor portion of the solenoid. It's difficult for me to envision how there could develop a high-resistance current path to chassis ground from that post when the solenoid's plunger is at rest, so I'm skeptical that you'll find the problem there. But, to separate the solenoid (and only the solenoid from the) from the rest of the vehicle's electrical system, do as Jack instructed in post #7 above.

Obviously, you should disconnect the battery before disconnecting and re-connecting any of the aforementioned wires, and the battery must be re-connected when measuring for the presence of the current. Be sure also to not allow any exposed contacts on wires that could possibly be "live" to make contact with anything conductive while those wires are floating around loose and the battery is connected.

Live well,

SJW

 

I'll add that, if the parasitic current is flowing through the solenoid's coil windings, the source of that fault will be elsewhere, such as a high-resistance "leakage" path within the ignition switch between its Battery and Start contacts, or at the firewall connector (think "corrosion"), etc.

There should be no current path between +DC and the solenoid's windings when the key is OFF. If the parasitic current is passing through the solenoid windings, replacing the solenoid won't solve the problem.

Live well,

SJW

 

If all else fails you can try to isolate the problem by removing fuses one at a time, that way you will know where to look. You should have a good set of line diagrams.

Milliamp

 

There are a lot of unfused components in a C2. Removing fuses would only eliminate the ones that are fused, and with the key off, most of the fused ones don't have power either. A drain when the key is off would not involve any fuse except the brake lights, courtesy lights, glove box light and clock, all on the bottom fuse. His drain is with the key off. This has been an ongoing series of threads by rowingone where most of the components of the car have been eliminated.

Following is his last post in another thread about this drain where he claims to have found the problem. He is currently still testing to be sure:

Miracles do happen. When I removed the solenoid wire clip and harness and connected 20 black and 10 red to the positive cable . . no draw!! There is a small chafe I believe from the wire clip that must have been the culprit. I am not 100% there yet . . I will wrap both wires with high temp tape and reinstall and hopefully I will be done! A couple positives from all of this .. I understand my electrical system better thanks to all the experts on here and every connection I unhooked got cleaned and treated with Kontac (a connection treatment that I use for audio equipment) so those 60 year old connections will have less resistance now and make better contact. It's only 930 AM but I feel like I should have a beer!