Some people like their engine bay clean and sparkly. Others prefer a dirty engine bay that runs. I walk the thin line between the two. I rarely clean anything in the engine bay unless it is absolutely necessary.
I peg all this to the fear of messing up one of the many electronics my 2012 jalopy has under the hood. Water on ignition coils, in spark plug tubes, on a sensor, the ECU, fusebox, or even the alternator is never good news.
And the alternator is the biggest culprit since it is the car’s powerplant. Washing it haphazardly will render it useless.
Water Ruins Electronics – Keep it Off at All Costs
By now, we all know water can wreak havoc on any electronic. That is why you won’t see anyone dunking their iPhone into a pool of water even though it is waterproof to some extent.
The same applies to car electronics. While manufacturers do a great job at waterproofing, their efforts can only do so much.
Your car might survive some dampness, calculated gentle washing, and accidental water spills. However, you shouldn’t keep testing the limits by hosing down the car whenever you get an opportunity.
That is why wise detailers and DIYers take precautions when cleaning the engine bay. Some of the measures I take include:
- Disconnecting both terminals from the battery to cut power (disconnecting the ground (negative) should suffice but I like overkills)
- Wrapping up sensitive electronics like the alternator, injector, ignition coils and any computer modules
- Using a low-pressure stream of water when cleaning
- Directing the water away from high-risk areas and using as little water as possible
- Letting the car dry with the hood open for up to three days (depending on the weather) before returning the battery and attempting to crank it
With my technique in mind, you can see that I rarely work on the alternator. It can collect gunk and grime over time. If I find it unsightly, I use a different cleaning technique.
Is it Safe to Wash the Alternator?
It depends on how you wash it.
While most detailers will tell you it is safe to wash an alternator, many mechanics and car enthusiasts will object.
As a self-taught mechanic who has had an alternator and ignition coils fail after washing the engine bay, I prefer using the phrase cleaning instead of washing.
Washing sounds like dousing it with a pressure washer and scrubbing off the grime with a brush and some degreaser. This will ruin your alternator.
Cleaning, on the other hand, is a meticulous process using minimal water and more evaporative cleaners to restore the alternator’s look.
How to Safely Clean an Alternator
Let’s start with some contradictions. The safest way to clean an alternator is not to clean it. Don’t think of cleaning just because you successfully cleaned the rest of the engine and want it sparkly clean.
You should only consider cleaning your alternator if:
- It is very dirty from oil spills and other grime from a recently damaged engine
- It has unsightly mud splatters and caked dust
- It is partly corroded and rusted
Start By Blasting it With Some Pressurized Air
You’ll be surprised how much dust and grime you can take care of with a dry brush and some pressurized air. Think of it like reverse-vacuuming your engine bay and the alternator.
- Get a small soft-bristled brush or a toothbrush.
- Get an air compressor, vacuum on blow mode, or even an air dryer.
The idea here is to use the brush to knock loose some dust and gunk before blowing it away with the compressed air.
- Start by giving the alternator a quick blast of air to blow away any loose dust and debris.
- Start scrubbing it gently with the toothbrush as you keep blowing to remove any grime you can dislodge without using water.
This procedure works best if you don’t have oil, coolant, or other contaminants turning the dust and dirt into a sloppy mess.
Apart from being a good technique to clean your alternator, you can use the compressed air and brush to keep the rest of the engine bay clean.
Your engine won’t get dirty and grimy if you keep blowing the loose dust and debris away before it coagulates. I use this technique on my engine bay, and it stays spotless for months without needing a wet rug – let alone a wash.
If the starter is dirtier, it is time to break out the big tools.
How to Deep Clean a Dirty Alternator
Deep cleaning an alternator correctly is an involving process. It isn’t a fast slapdash job with some degreaser and a pressure washer. The safest way needs the alternator on a bench.
Remove the Alternator from the Car
We need unfettered access to the alternator for proper cleaning. You can achieve this by removing it from the car. The disassembly process varies from one car to another. Either way, it takes the following form.
- Releasing tension on the serpentine belt and removing it from the alternator pulley
- Unplugging and unbolting all electrical terminals from the alternator
- Unbolting the alternator from the engine
- Removing the alternator from the engine and placing it on a sturdy working space
Get the Cleaners
We won’t be cleaning our alternators with good old water. The risk is too high. Instead, we will use specialty cleaners that evaporate faster and better than water. This reduces the chances of short-circuiting and damaging components in the alternator.
CRC Alternator Cleaner
This is a fast evaporating cleaner and degreaser used to remove oil, grime, and dirt from surfaces. It will penetrate into unreachable parts of the alternator, dissolving and washing away the dirt, leaving your alternator looking better and presentable.
It is strong enough to work on oil, sticky residue, and dust, but it isn’t corrosive enough to damage winding insulation, diodes, and other components in the alternator assembly.
White Spirit
If you can’t get your hands on CRC but have much white spirit lying around, use it as the cleaner and liquid to eliminate dirt and grime on your alternator. Even though it washes away paint, it isn’t strong enough to remove the crucial enamel coating on your alternator’s windings.
It has a low evaporation point, so it will soon be gone from your alternator a few hours after you are done cleaning.
Apart from the correct cleaner, you will also need:
- Some clean rugs
- An air compressor
- Two soft bristle brushes
- A bucket
Here is what to do
- Start by using the air compressor and one brush to break off any loose dirt and grime, following the procedure we outlined in cleaning the alternator with air.
- Pour some of the cleaners(CRC or White Spirit) into a bucket and soak the rug.
- Use the rug and apply the cleaner onto the alternator paying attention to the dirtiest places.
- Let the cleaner sit on the alternator for five minutes. You can leave the rag wrapped around the alternator to soak more of the cleaner.
- Remove the rug and use the second soft bristle brush to scrub loose any stuck dirt.
- Use the rug already soaked to wipe off most of the gunk from the alternator.
- Use your cleaner of choice to rinse off dirt and grime. Some people go the easy way and use water for the rinse cycle, but I prefer using CRC or White Spirit for this step. The whole idea was doing away with water, after all.
- Let the alternator dry out in a cool and dry place with good airflow for up to five days.
- You can use a fan or hair dryer on low heat to make it dry faster.
While cleaning the alternator, pay special attention to the terminals. These directly impact the alternator’s performance. Knock off any grime or corrosion and gently buff the terminal with a scouring pad to expose fresh copper for perfect contact.
- Never spray the cleaner or air directly into the alternator’s air inlet or the windings.
- Don’t soak the alternator into a bucket or container of the cleaner
- Don’t use any petroleum degreases or soap
- Never pressure wash the alternator
- Don’t be in a rush to test or reinstall the alternator. Allow for at least three days to dry (or more if the weather is cold or humid)
How to Clean an Alternator Without Removing it
If you don’t have the tools, skills, or times to remove the alternator from the vehicle but still need to clean it, you can follow these steps:
- Use an air compressor to blow off most of the dust from the alternator.
- Use a dry soft bristle brush to knock loose stuck debris from the alternator while using the pressurized air to blow away.
- Unhook all the terminals and use a slightly abrasive scouring pad to remove any corrosion and grime
- Dip a clean rag into CRC cleaner or White Spirit and wring it so that it remains damp but not dripping wet
- Use it to wipe the surfaces of the alternator clean
- Let the car remain unpowered for a day to ensure all the cleaner evaporates
- Reattach the terminals and start your car
Is it Safe to Wash the Alternator?
Technically, washing your alternator with water or any solvent is safe – as long as you don’t power it on until it is 100% dry. However, I discourage washing because it is hard to determine when the alternator is 100% dry.
Washing becomes a gamble. Cleaning it carefully with alternative fast-evaporating solvents and no running water is a better alternative.
The only time I can use water and a degrease on an alternator is if I fully disassembled the unit and I am trying to rebuild or refurbish it. I wouldn’t wash a working alternator.
How Often Should I Clean My Alternator?
Don’t clean the alternator unless it is absolutely necessary. Keeping any liquid off your alternator, by all means, is the best way to keep it operational for longer.
- Protect it from dirt, oil spills, and dust at all costs
- Use an air compressor to blow off any dust before it settles
- Remember, a dirty working alternator is better than a clean alternator that doesn’t work. Resist the urge if the alternator is just unsightly but still useable
Can You Use Brake Cleaner on an Alternator
Brake cleaner is a viable parts cleaner that you can use to get all that dirt and grime off your alternator. It evaporates fast at room temperature meaning most of it will be gone within a day or two.
The only problem is that brake cleaner damages plastic or rubber. It will ruin any gaskets on the connectors or protective rubber grommets and make plastic parts of the alternator fail faster.
Moreover, since it comes in ready-to-spray cans, people misuse it by spraying it directly onto the alternator.
Can I Spray WD40 on My Alternator?
Even though WD40 can clean and degrease, it doesn’t evaporate fast enough. It also has faint lubricant properties meaning that residue it could make your alternator belt slip. However, since WD40 doesn’t conduct electricity, it could be a viable cleaner on contacts, circuit boards, and even the windings, as it will not cause a short circuit.
Don’t spray it directly onto the alternator, however. You can spray it on a rag and use it to wipe down the alternator instead.