22 votes
Accepted

40amp protection on 25amp rated wiring?

The maximum rating of 25A will be for continuous use. The 40A fuse is there to blow very quickly in a fault condition. If you look at this page https://en.wikipedia.org/wiki/American_wire_gauge 2mm² ...
HandyHowie's user avatar
  • 25.2k
21 votes
Accepted

Can I connect wires by just twisting them together and insulating with tape?

While the twist/tape method will make the connections and work, I tend to leave this for the quick fix. Over time, with the everyday vibrations occurring, this method tends to allow for continuity ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
19 votes

What can I do to combat wire embrittlement?

Heat and thermal stress, even at engine bay temperatures, is not generally the cause of copper wire failure. There is "hydrogen embrittlement" for copper but that only really comes into play at 400C+ ...
Jason C's user avatar
  • 4,890
16 votes

Can I connect wires by just twisting them together and insulating with tape?

@Pᴀᴜʟsᴛᴇʀ2's answer is excellent. But, I'd like to add: rather than just twist & tape, there's something called a "lineman's splice," or "Western Union splice" which provides a great electrical ...
3Dave's user avatar
  • 3,149
14 votes
Accepted

Is it ok to plug in battery backward to do compression test?

This engine is equipped with a voltage regulator. Depending on the exact construction of the regulator a reverse current would be disastrous, especially the high current from a starter battery
Martin's user avatar
  • 8,448
10 votes

What can I do to combat wire embrittlement?

When you say "embrittlement", are you talking about this? This is a common issue with PVC used as insulation: PVC is brittle by nature an needs plasticizers to be added to it when making cable ...
Dmitry Grigoryev's user avatar
9 votes
Accepted

Testing specific wires in harness cable

This is quite easy, but you need to do yourself a favor and get a factory wiring diagram. It will save you hours of frustration and confusion. The factory wiring diagrams will tell you exactly when ...
cloudnyn3's user avatar
  • 3,333
9 votes

Is it ok to plug in battery backward to do compression test?

Why not just put a wrench on the crankshaft? Ignoring the electrical repercussions, I fear damage to the starter, too. Besides, if the starter on this tractor uses a sprag clutch (and probably most ...
justinm410's user avatar
  • 1,722
9 votes
Accepted

How to remove a stuck (maybe melted) connector from the blower motor resistor

The connector will need to be replaced. It looks to be fused together. The metal connector terminals were the cause of the original problem. The usual problem is that the connector makes poor contact ...
Fred Wilson's user avatar
  • 11.6k
8 votes

Why do cars still use mechanical blinker relays?

I can think of several reasons straight away: Cheap Easy to replace Have a very distinctive click that makes it obvious when they are on, and when a bulb has failed Are very well understood Anyone ...
Rory Alsop's user avatar
  • 18.6k
8 votes

Is it ok to plug in battery backward to do compression test?

Looks like the starter drive is the typical spring loaded drive gear that engages when the starter motor turns in the "forward" direction, then disengages if the engine starts running and overdrives ...
Johnny's user avatar
  • 452
8 votes

Wiring extra truck battery to power winch

The method suggested by Paulster2 will certainly work. Another way to do it at lower cost is to use a 12 volt, 120 amp continuous duty relay. Make a permanent connection with heavy cable from the ...
MTA's user avatar
  • 6,125
7 votes
Accepted

What can I do to combat wire embrittlement?

The very short answer is that heat isn't a significant problem for the wire. Heat is a problem for the insulation. So if you have wires failing I think there is something else going on. The ...
dlu's user avatar
  • 14.5k
7 votes

Can stock headlight wiring deal with 110 W bulbs?

0.85 mm² copper wires have a resistance of about 0.02 ohm/m, and when a current of about 10 A is driven through this wire, it dissipates about 2 W/m. This isn't soo much and should not ...
sweber's user avatar
  • 7,057
7 votes
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Car alarm install. Should I interrupt starter or ignition?

The average aftermarket car alarm uses cheap components and is not designed for high reliability and long life. This is not to criticize the particular model that you plan to install, but I'm speaking ...
MTA's user avatar
  • 6,125
7 votes

Does the hood pin-switch here constitute an electrical risk?

TL DR: It shouldn't be a concern whatsoever. If the switch is like any other of this type, the idea is for the hood to come down and press down on it, and thus disconnecting the grounding source. In ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
7 votes

Wiring extra truck battery to power winch

I think the easiest way to accomplish this is the get a 12vdc to 12vdc charger to use to charge the battery, then keep the wiring to the winch as direct wiring without connecting into the truck's ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
6 votes

How to remove a stuck (maybe melted) connector from the blower motor resistor

Dont you have to remove the connector with the green/black wire also? In your photo it looks like the connectors are melted together. You can get a knife and try to seperate them first. The blue ...
Evren Yurtesen's user avatar
6 votes
Accepted

Can stock headlight wiring deal with 110 W bulbs?

TL;DR: You're on the edge, instead of pushing it, use the existing circuit to control a set of relays and supply the bulbs with a short run of larger wire. Use at least 3.3 mm² (12 AWG) wire, which ...
dlu's user avatar
  • 14.5k
5 votes

Modding Honda Ridgeline cigarette lighter to power USB ports

The power socket has a simple two cavity connector. It will most likely have #2 female spade connectors. Connect a new device with male spade connectors after first verifying polarity. I would not ...
Fred Wilson's user avatar
  • 11.6k
5 votes

Where can I find a power adapter to run a car stereo from a wall outlet?

Your car Audio should work well in your garage .Mine has been running for 17 years now .The 12 V DC power supply needs to be rated for the job as others have commented .If you use a switchmode ...
Autistic's user avatar
  • 2,083
5 votes

Mini Cooper 2003 - Identify rear indicator light wiring to install LED resistor

I'm going to answer this in a general way because for someone to tell you what the wires mean, they would need to follow this procedure, or have access to detailed wiring diagrams for your car. You'...
JPhi1618's user avatar
  • 13.2k
5 votes
Accepted

Is there something that can be applied to electrical connections to prevent rust and corrosion?

In general silicone gease applied to the parts before and after assembly is a good way to go. It will be pushed out of the way where you have tight metal to metal contact so it won't cause electrical ...
Peter Green's user avatar
5 votes

Is it ok to plug in battery backward to do compression test?

Even if there are no polarity-sensitive electronics to damage and the starter motor was able to engage, it is unlikely that the motor would rotate backwards anyway. Most car starter motors (in fact ...
nnxen's user avatar
  • 51
5 votes

What is this covering used on the wires (blue and yellow). I found it on my KTM 390 Wiring Harness

The black material sheathing the blue and yellow wires is commonly called wire loom. It serves to organize the wires and protect them from damage. There are three main types that I am familiar with: ...
dlu's user avatar
  • 14.5k
5 votes

What's wrong with using domestic flex cable for automotive purposes?

Automotive cables are normed (ISO 6722 ?). The insulation of automotive cables offer a superior resistance to heat, cold, chemicals and vibration. A common FLYR-cable should guarantee its insulation ...
Martin's user avatar
  • 8,448
5 votes
Accepted

What type of crimping pliers do I need for these connectors

I believe crimping pliers for weather pack, metri-pack, or molex connectors will work. IWISS makes a tool just for those types of connectors. Alternatively, Paladin makes a crimping tool with die ...
PICyPICyPICy's user avatar
5 votes
Accepted

How to wire a glow plug?

A glow plug is essentially an intentional short circuit that heats up a wire and ignites whatever fuel is in or connected to the glow plug. Polarity rarely matters in this. But typically, the ...
cde's user avatar
  • 603

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