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Fried engine harness (I think)
I think I know the answer to this but figured I’d check with the experts. I had to remove the alternator from my ‘70 today (to access fuel line) and during reassembly I pinched the wire loom between the alternator bracket and intake. When I went to put the negative battery cable back on, there were sparks everywhere and smile started drifting up along the loom down to the starter. Ugh. My question is:
Can I repair the engine harness by simply cutting off the part that got pinched or do I need to replace the entire harness? Not sure if it shows up very clear in the photo but there is copper showing in the red wire. https://uploads.tapatalk-cdn.com/201...4e09dd486b.jpg Sent from my iPhone using Tapatalk |
I would expose the harness and take a good look at it.....I would repair it, if it seems to be just that area.....
But I would solder the repair joints no butt connectors.....then shrink tube each repair joint...then tape over it... If it's the original harness then it may be time to replace it wires do become brittle after 40 years..... |
Thanks. It is a newer M&H harness. About 7 yr old. Maybe 1000 miles on it. I noticed that the tar wrap appears to have white residue on it all along the way harness back to the starter. Is that from heating up too much when I connected the battery?
Also, do you think I damaged my starter solenoid? Sent from my iPhone using Tapatalk |
Looks like you pinched the alt wire, shouldn't be any starter related damage. Unrap the harness covering & check how far the burned section is, as the other poster said. If the copper wire is not burned or fused, it can probably be taped up [ insulated ] & re-used. Depends how long the juice was applied, smoke may just have been the insulation smoking, no wire damage.
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Thanks Geoff. I’ll do just that. Unwrap it for a section and see how much damage I’ve done. I guess I get to wear a dunce cap now. :(
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So I followed the suggestions offered here and was able to ‘save’ the harness by repairing it, but I think this was a temporary fix. I wasn’t able to solder the thick red wire. I’m new to doing electrical work but no matter how long I held the soldering gun on the wire, it never got hot enough for the solder to melt. I was holding the soldering gun tip at the bottom of the spliced wire (I think that’s correct way) and then touching solder to top of splice. I thought it was supposed to wick through but nothing happened. I know the gun was hot enough because if I touched the solder to the tip of the gun, that melted it. Any suggestions?
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[QUOTE=racerboy;6058275I know the gun was hot enough because if I touched the solder to the tip of the gun, that melted it. Any suggestions?[/QUOTE]
Make sure the locking nuts or set screws that hold the tip to the soldering gun are nice and tight. |
It may take awhile for the wiring splice to get hot enough to melt the solder. The whole length of wire acts like a big heat sink that pulls the heat away from the splice. The bigger the wire, the harder it is to heat up. Eventually it will.
A lot depends on the size of your iron and its wattage output. Pencil tip irons will take a long time to heat up the larger wiring. |
Use a propane torch to solder your connections. It will heat much faster. Just be careful to shield things around the area so you don't damage something else.
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I realize that many believe, and in the past have been advised, to solder connections, but, it is better to use quality non-insulated butt connectors, crimped with a quality crimper, and use shrink tubing.
If you want to blaze me on that statement, watch this before you do: https://www.youtube.com/watch?v=faLn-SjVfwY The Klein Tools crimper is the 'correct' crimper to use: https://www.kleintools.com/catalog/c...ated-terminals Home Depot carries Klein Tools crimpers. Use nickel plated non-insulated barrel terminals like these: https://www.waytekwire.com/products/...=Nickel-Plated They are rated for high heat, but I use them across the board. If you want to use open ended connectors, such as the Packard 56 series, use the appropriate terminals and crimpers, also available from a variety of auto wire warehouses and Summit. The Casper one is fine and inexpensive: https://www.summitracing.com/parts/c...CABEgK4vPD_BwE Terminal Supply has 101 videos that are great on crimping: https://www.youtube.com/watch?v=LXDedfvmI_0 Only use GLX or TLX wire, especially under the hood, no parts store cheap 'primary wire'. It can't tolerate the heat. https://www.wirebarn.com/GXL-Automot...Foot_c_29.html For those wires, I would unwrap a few inches, stagger the cuts and butt connectors, shrink wrap them, then use the same type of harness wrap that the existing harness was wrapped in. That too is available at Waytek Wire. I did a ton of homework prior to wiring my entire car, customizing it, and it's also using an EFI setup. I wanted to make SURE I did it right, and did it only once. . |
The below is good information. I spent almost 40 years working as an engineer, engineering manager and program manager for a automotive tier one wiring supplier.
I use open barrel splice clips, followed by just a touch of solder in case I didn't get a gas tight crimp and then I cover with a heat shrink. Quote:
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Appreciate the advice. Unfortunately, none of the photos from your post are appearing (at least not on my phone). Is this the crimper you were suggesting: https://uploads.tapatalk-cdn.com/201...16ce43186a.jpg Sent from my iPhone using Tapatalk |
No. This is it. https://smile.amazon.com/Non-Insulat...s%2C235&sr=8-1
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I would have contacted M&H to find out how much they would have charged to fix it.
As someone who has to cut/strip TFE, PTFE, ETFE and Kapton insulated silver plated and nickel plated copper wires all day long, a single splicing would be a treat. Also what solder type are you using? As a J-STD-001 solder certified person, it sounds like you haven't been using flux to help with the solder flow or you're using RoHS compliant solder (no lead). They also have solder filled butt connectors nowadays. |
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Basically, depending on the actual application, it's a matter of achieving a 'quality' solder joint. Without the proper training, materials, and tools, the chances of creating a quality solder joint is greatly decreased. It's much easier to consistently achieve a proper joint using crimp stuff. But of course, you still need to have the proper materials and tools. (as well as some minimal training/practice.) HFR, no doubt you could pull off a quality solder joint! . |
I do like the ratcheting crimpers that accept an assortment of dies, it's a good way to start with quality crimping. As you have other crimping needs, you just buy the dies, and don't have to buy a whole new set of pliers.
Once you've used the ratcheting crimpers to make spark plug wires, you will never go back to using premade, long/short, all over the place plug wires. Or mess with the silly plastic tools that come with the wires. The MSD one is a quality unit, but it is a touch pricey. It looks like a Panduit, but not sure. https://www.holley.com/products/elec...ls/parts/35051 You can see the available dies here: https://www.holley.com/brands/msd/pr.../wiring_tools/ I use these to do large gauge crimping, like for battery terminals and such. Works great, and inexpensive: https://www.amazon.com/Amzdeal-Crimp...=fsclp_pl_dp_3 . |
I ordered the Klein crimpers and the non-insulated connectors from Waytek. I wasn't sure how to order the wire (seems like you have to buy a lot fo any given gauge). Will send some pics once the parts come in and I make the repairs. Appreciate all the help!
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This is probably a dumb question, but is there a tool that can accuratley tell what gauge a wire is?
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No, there's kind of no need, you can pretty much tell by looking at the wire core thickness itself. If you wanted, you could use small lengths of know gauge wire with one end stripped for comparison.
Keep in mind the wire cover thickness varies greatly, and total diameter really can't be used to judge the wire gauge. Also, 'cheap' wire uses a lower grade or coated cores (higher resistance, easier corrosion), and they don't always meet the standards for the gauge of wire they advertise on the package. Which is why they don't mark the wire cover with the gauge. . |
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