Recurring problem, thought I had fixed. I keep killing starter solenoids. About to be on the fifth one since changing my engine and painting my engine compartment. I get a visible spark at the solenoid and then it stops working shortly after (one or two starts). Thought it needed to be grounded to the engine compartment so I scraped some paint off behind it so the metal could touch back when I first had the problem. Thought it fixed it, but apparently not. Ideas? Has a new battery, new starter, new terminals and cables going to and from it and the starter.. Could I just need to scrape more paint so it can ground better?
Not a bad idea, a spark is indication the ground is poor... There is no such thing as too good of a ground, any corrosion will just get worse over time... A light coat of dielectric grease on the back of the solenoid may be a good idea in this instance...
A spark is indication that designed path of electron flow in the circuit is impeded, and a weakness in front of the impedance has allowed a more direct path to a grounding point than the intended ground or load point. How clean are your wires? Typically you would only see a spark around a part like that if something was arcing from a hot wire to the housing(or a crack in the housing/insulation that leads to a hot wire inside the housing; I rule this out because it has happened to more than 1 solenoid) in an effort to reach ground. I would expect that your housing has a great ground, and that you have some corroded and damaged wires.
That's a good point.. My engine is grounded behind the attaching bolt for my horn and I was just messing with the horn trying to hook it back up. I'll check. That's a really good idea! Keep that ground from getting corroded. Thanks guys! Gotta work today, but I'll be trying these tomorrow morning!
I'll try cleaning them off too.. They're looking pretty good because they're so new, but you never know. I have accessories wired on to the solenoid posts... (electrical choke, auxillary fuse bock with nothing attached to it). Would the order on the post matter? Even tho I think I've had this problem before I added that stuff..
Order doesn't matter. But if any of those items had a poor ground the electron flow down those wires would be impeded. Thought I'd add a little more to the thought processes for diagnosing this. What you get from the starter solenoid is essentially a grounded switch with the potential to create a ground loop at it's location. Because part of what it does (the stock one) is mix the battery and alternator voltage sources, it is a primary diagnoses and failure point for multiple circuits. Because, the solenoid is not itself a voltage source it would be very rare for any spark to be originating from it (under conventional electron flow, not actual). It's more likely some accessory has a bad ground and where you have it connected to the terminal on the starter solenoid is arcing to the housing, because the electrons are impeded in their flow down the wire. I forgot to check, is this a stock starter solenoid, or do you have a new starter with the solenoid on it. Because, this would put my opinion more in line with Krazy Comets.
The solenoid mounting bracket has to be well grounded for the solenoid to work correctly. IIRC mine pulls about 4 amps. Many years ago I moved the solenoid to below the battery tray to clean up the wiring mess (there's no voltage regulator there now, either). I tapped the battery tray bolt hole and ran a bolt through from the outside to act as a ground stud for the solenoid bracket. The (-) battery cable passes right by there so I "window" stripped the cable, soldered on a copper clamp and attached to the same stud as the solenoid bracket. That point is where I now pick up the ground for any circuits I add to the car.
@MSmith - It's a stock solenoid. Maybe I should try unhooking the aux fuse box too? (nothing's hooked up to it yet) It's the only accessory I've added since I fixed the problem previously.. Yea, I think I'm definitely gonna try and ground the mounting bracket better. Almost positive the spark is coming between the mounting bracket and the fender wall.. That's where all the carbon and burnt look is. Mainly on the starter side, between the mounting bracket and the fender wall. A ground stud might be a good add-on for the future either way.. Good thinking! My sister's pt cruiser has a ground stud in the engine compartment for when you need to jump the car. It's a nice feature to have.
Take a picture of your Solenoid/wiring and post it. Do you have a multi-meter (Voltage Tester) ? All the above advice is good advice. If you don't show progress, let's start with checking the basics: Battery voltages, resistance between each section: (from Battery, to Starter Positive). ***And do not measure any resistances, until you check with us...or you could fry something.
Sorry guys. Ended up having to work again yesterday. Have a couple of hours this morning.. Gonna see if I can squeeze it in.
Alright guys, here's the skinny. I couldn't take pictures cause I was doing this in the rain, but it appears my positive battery cable broke. I had it bolted to one of the accessory holes in the passenger side head. Underneath the washer, and out of sight, the hole on the cable end was split in half and very ugly looking. I cleaned it and the head surface up, bolt it back down as tight as I could, and have been driving the Mav everywhere I've gone today! I have to adjust my trans vac modulator I put in today (like alil more kick in the shift), and my thermactor plugs are gonna take some juicing... But electrical problem solved! Thanks guys! I'll save that old selenoid as a backup just in case... but pretty sure I fried it.
