How we researched this guide
We compared 5 products: 2 Permatex defogger repair kits and 3 FrostGuard windshield covers and shades. We checked maker and listing evidence for all 5, including part numbers, sizes, and cure times.
Repair claims are maker descriptions and retailer specs; owner points are paraphrased listing themes, not quoted reviews, and no star ratings are used. Where a listing shows no featured offers, that is noted, not hidden.
The 30-second answer
For a broken defogger, the Permatex 09117 complete kit leads, with the 21351 tab adhesive for detached tabs alone. For prevention, the FrostGuard Plus XL suits big vehicles, the NFL standard suits cars, and the FrostGuard Sunshade handles summer heat.
Best Overall
Permatex Complete Rear Window Defogger Repair Kit 09117
A complete kit for repairing damaged rear window defogger grids and tabs, with conductive paint, tab adhesive, and step-by-step instructions.
Best for Detached Tabs
Permatex Defogger Tab Adhesive 21351
A weather-resistant conductive adhesive kit that restores electrical connectivity to detached rear window defogger tabs.
Best Winter Cover
FrostGuard Plus Winter Windshield Cover XL
A full-protection winter windshield cover, 68 by 41 inches, with security panels, wiper blade coverage, and side mirror covers.
Best Sun Protection
FrostGuard Sunshade for Car Windshield
A universal-fit reflective windshield sunshade that blocks UV rays, cuts interior heat, and protects the dashboard, with anti-theft security flaps.
Best Team Edition
FrostGuard NFL Windshield Cover Standard
A standard-size winter windshield cover, 60 by 40 inches, with side mirror covers, sized for most cars, sedans, small trucks, and SUVs.
| Product | Type | Standout spec | Best for | Check Price |
|---|---|---|---|---|
| Permatex Complete Rear Window Defogger Repair Kit 09117 | Grid and tab repair kit | Conductive repair, 0.095 oz | Broken defogger grids | |
| Permatex Defogger Tab Adhesive 21351 | Tab adhesive kit | Conductive tab adhesive | Detached defogger tabs | |
| FrostGuard Plus Winter Windshield Cover XL | Winter windshield cover | 68 x 41 in, mirror covers | SUVs and trucks in snow | |
| FrostGuard Sunshade for Car Windshield | Reflective sunshade | UV-blocking, standard size | Hot-climate cars | |
| FrostGuard NFL Windshield Cover Standard | Winter windshield cover | 60 x 40 in, mirror covers | Cars and small SUVs |
Defroster fix chooser
Enter how many defogger grid lines are dead. The result recommends one product from this guide.
Enter a value above to see a recommendation.
How to choose defroster accessories
Diagnose before you buy
A dead defogger can be a fuse, relay, switch, wiring fault, broken grid, or detached tab. Test the electrics first: a repair kit cannot fix a blown fuse, and a cover cannot fix a broken grid.
Grid repair basics
Clean the glass, mask the broken line precisely, apply conductive paint thinly, and cure fully. Rushing the cure is the top cause of failed repairs, so give it the full 24 hours the retailer spec states.
Tab repair basics
A detached tab needs clean bonding faces and conductive adhesive, held until set. If the tab or grid contact is corroded, clean it gently first or the bond will fail electrically even if it holds physically.
Prevention with covers
Winter covers stop frost bonding to glass; sunshades stop heat and UV damage. Fit covers before the weather hits, remove them before driving, and dry them before packing away.
Size honesty for covers
Measure your windshield before ordering a cover. XL covers on small cars flap and pool water; standard covers on trucks leave glass exposed. Both FrostGuard sizes are in this guide for that reason.
When to see a professional
Full-grid failure, damaged glass, or any electrical fault beyond fuses and relays belongs to a shop. Rear glass replacement is expensive, but a botched DIY repair on structural glass costs more.
Defroster accessory fitment data
Maker-stated fits and specs from the listings. Diagnose the fault before choosing a product class.
| Fault or need | Product class | Key spec | Source |
|---|---|---|---|
| Broken grid lines | Complete repair kit | 09117, 24-hour cure | Permatex 09117 listing |
| Detached tab only | Tab adhesive | 21351, conductive | Permatex 21351 listing |
| Frost on XL vehicle | Winter cover XL | 68 x 41 in | FrostGuard Plus listing |
| Frost on standard car | Winter cover standard | 60 x 40 in | FrostGuard NFL listing |
| Summer heat and UV | Reflective sunshade | 53240, UV-blocking | FrostGuard Sunshade listing |
| Whole grid dead | Professional diagnosis | Fuse, relay, switch first | General maker guidance |
Defroster accessories by budget
| Budget tier | What you get | Example pick |
|---|---|---|
| Budget | Single repair kit for one fault | Permatex Tab Adhesive 21351 |
| Mid-range | Complete grid repair or winter cover | Permatex 09117 / FrostGuard NFL |
| Full protection | Repair plus prevention for all seasons | Permatex 09117 + FrostGuard Plus XL |
Types of defroster accessories
| Type | Pros | Cons | Best for |
|---|---|---|---|
| Grid repair kit | Restores heating | Fiddly, needs curing | Broken grid lines |
| Tab adhesive | Restores tab connection | Tabs only | Detached tabs |
| Winter cover | Prevents frost bonding | Exterior fitting each night | Outdoor winter parking |
| Sunshade | Cuts heat and UV | Not a winter product | Hot climates |
| Professional repair | Handles electrical faults | Highest cost | Full-grid or wiring faults |
Detailed reviews: defroster accessories
Each accessory below is judged on the fault it fixes, the evidence for its claims, and where it falls short.
Best Overall: Permatex Complete Rear Window Defogger Repair Kit 09117
Best Overall — Best for repairing broken defogger grids
Why the Permatex Defogger Repair Kit is our pick
A defroster accessory guide has to start with the part that actually fixes a dead defroster, and this kit is it: conductive paint for broken grid lines plus adhesive for detached tabs, in one box. It is the only pick here that restores heating rather than working around it.
Permatex Defogger Repair Kit key specs
- Form: complete defogger repair kit
- Part number: 09117
- Volume: 0.095 oz (2.8 ml)
- Material: acrylic resin with metallic silver
- Repair type: grids and detached tabs
- Cure: full cure 24 hours per retailer spec
- Fit: universal, no specific vehicle fitment
- Use: works on detached tabs and damaged grid lines
- Instructions: photographic instructions included
- Maker: Permatex
Permatex Defogger Repair Kit: fits and best for
Best for cars with one or more dead grid lines or a detached tab where the rest of the grid still works. It suits DIY owners comfortable with careful masking and a 24-hour cure.
Permatex Defogger Repair Kit pros and watch-outs
- Repairs both grids and tabs
- Universal fit across makes
- Photographic instructions included
- Far cheaper than glass replacement
- Professional-grade conductive formula
- Only repairs one grid line per kit in practice
- Needs 24-hour cure before use
- Fiddly masking and prep work
- Will not fix a failed switch, relay, or wiring fault
Permatex Defogger Repair Kit: what owners report
- Owners report dead lines heating again after careful application (listing feedback).
- Owners report masking cleanly is the hardest part (listing feedback).
- Owners report patience with curing matters more than speed (listing feedback).
Permatex Defogger Repair Kit: who should not buy
Skip this if the whole grid is dead or the fault is electrical upstream; test the fuse, relay, and switch first.
Permatex Defogger Repair Kit: pair it with
Pair it with a multimeter check of the grid before and after repair to prove the fix.
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Mask both sides of the broken line and let it cure the full 24 hours. See 12V car heater reviews for cabin heat backup.
Best for Detached Tabs: Permatex Defogger Tab Adhesive 21351
Best for Detached Tabs — Best for reattaching a detached defogger tab
Why the Permatex Tab Adhesive is our pick
Detached tabs are the most common single-point defroster failure, and this kit targets exactly that: a conductive adhesive that re-bonds the tab to the grid. It is cheaper and simpler than the full grid kit when the grid itself is intact.
Permatex Tab Adhesive key specs
- Form: tab adhesive kit
- Part number: 21351
- Repair type: detached defogger tabs
- Material: electrically conductive adhesive
- Fit: universal for most rear defogger grids
- Weather resistance: weather-resistant per listing
- Use: restores tab-to-grid connectivity
- Cure: per maker instructions
- Contents: adhesive plus application aids
- Maker: Permatex
Permatex Tab Adhesive: fits and best for
Best for cars where the tab has come off the glass but the grid lines are undamaged. Check that the tab and grid contact area are clean before bonding.
Permatex Tab Adhesive pros and watch-outs
- Targets the most common single failure
- Universal fit for most grids
- Weather-resistant bond
- Simpler than a full grid repair
- Restores factory-style connection
- Does not repair broken grid lines
- Bond needs clean surfaces and cure time
- One-tab job; multiple tabs need more kits
- Will not fix upstream electrical faults
Permatex Tab Adhesive: what owners report
- Owners report the tab holds after proper surface prep (listing feedback).
- Owners report it beats replacing the whole rear glass (listing feedback).
- Owners report following cure instructions is essential (listing feedback).
Permatex Tab Adhesive: who should not buy
Skip this if grid lines themselves are broken; buy the complete 09117 kit above instead.
Permatex Tab Adhesive: pair it with
Pair it with the complete kit if any grid lines are also damaged.
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Clean both bonding faces with alcohol and hold the tab until set. See 12V adapter reviews for electrical accessories.
Best Winter Cover: FrostGuard Plus Winter Windshield Cover XL
Best Winter Cover — Best for full winter windshield protection
Why the FrostGuard Plus XL is our pick
Prevention beats defrosting: this cover stops frost, ice, and snow from bonding to the glass in the first place, and it covers wipers and mirrors too. For owners who park outside in snow country, it saves the morning scrape and reduces defroster workload.
FrostGuard Plus XL key specs
- Form: winter windshield cover
- Size: 68 in x 41 in, XL
- Part number: 53325
- Coverage: windshield, wipers, and side mirrors
- Material: durable polyester with stick-resistant PVC lining
- Security: built-in security panels
- Fit: XL cars, trucks, and SUVs
- Warranty: 1-year maker warranty per listing
- Use: exterior, overnight frost and snow
- Maker: FrostGuard
FrostGuard Plus XL: fits and best for
Best for XL cars, trucks, and SUVs parked outside overnight in frost and snow. Measure your windshield; the XL size suits larger vehicles, and a standard size exists for smaller cars.
FrostGuard Plus XL pros and watch-outs
- Covers windshield, wipers, and mirrors
- Security panels resist theft and wind lift
- PVC lining resists sticking to ice
- 1-year warranty stated
- Saves morning defrost time
- XL only in this listing; smaller cars need the standard size
- Exterior cover needs fitting in cold weather
- Must be removed and dried before driving
- Does not repair an already-broken defroster
FrostGuard Plus XL: what owners report
- Owners report frost-free glass on covered mornings (listing feedback).
- Owners report the mirror covers are genuinely useful (listing feedback).
- Owners report security panels keep it in place overnight (listing feedback).
FrostGuard Plus XL: who should not buy
Skip this if you park in a garage; a cover adds nothing indoors. Spend on the repair kits above instead.
FrostGuard Plus XL: pair it with
Pair it with the Permatex repair kits if your rear defogger also needs attention.
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Fit it before the freeze, not after; a cover cannot melt ice already bonded. See emergency flashlights for winter kits.
Best Sun Protection: FrostGuard Sunshade for Car Windshield
Best Sun Protection — Best for sun and heat protection
Why the FrostGuard Sunshade is our pick
Defroster accessories are not only about winter: summer sun cracks dashboards and bakes interiors, and this shade is the same brand’s heat answer. Its reflective face and security flaps make it a genuine year-round companion to the winter cover, not a filler pick.
FrostGuard Sunshade key specs
- Form: reflective windshield sunshade
- Size: standard
- Part number: 53240
- Material: reflective, for exterior front-window use
- UV claim: blocks 99.9 percent of UVA per listing
- Heat claim: reduces interior temperatures by up to 55 percent per listing
- Security: anti-theft security flaps
- Fit: universal
- Warranty: 1-year maker warranty per listing
- Maker: FrostGuard
FrostGuard Sunshade: fits and best for
Best for cars parked in sun, especially in hot climates where dashboard cracking and cabin heat are real problems. Universal fit suits most front windows; check size against your windshield.
FrostGuard Sunshade pros and watch-outs
- Strong UV blocking claim
- Cuts interior heat sharply per listing
- Security flaps resist theft
- Protects the dashboard from cracking
- Lightweight and easy to store
- Standard size only in this listing
- Exterior fitting takes a minute each time
- Heat-reduction figures are maker claims
- Not a frost or snow product
FrostGuard Sunshade: what owners report
- Owners report noticeably cooler cabins on sunny days (listing feedback).
- Owners report the shade stays put with the flaps closed in doors (listing feedback).
- Owners report dashboard fading slows with regular use (listing feedback).
FrostGuard Sunshade: who should not buy
Skip this if your problem is winter frost; the FrostGuard Plus winter cover above is the right tool.
FrostGuard Sunshade: pair it with
Pair it with a dashboard cover for full interior sun protection.
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Close the flaps in the doors every time, or wind will take it. See first aid kits for complete car kits.
Best Team Edition: FrostGuard NFL Windshield Cover Standard
Best Team Edition — Best for standard-size cars in winter
Why the FrostGuard NFL Cover is our pick
The XL FrostGuard Plus is too big for a sedan, and this standard 60-by-40-inch version is the correct-size answer: same frost protection and mirror covers, cut for cars and small SUVs. Size honesty is the whole point of including both.
FrostGuard NFL Cover key specs
- Form: winter windshield cover
- Size: 60 in x 40 in, standard
- Part number: NFL standard edition
- Coverage: windshield plus side mirror covers
- Fit: most cars, sedans, small trucks, SUVs
- Material: winter cover fabric per listing
- Use: exterior, overnight frost and snow
- Extras: side mirror covers included
- Warranty: per maker listing
- Maker: FrostGuard
FrostGuard NFL Cover: fits and best for
Best for cars, sedans, and small SUVs parked outside in frost and snow. If your windshield is wider than 60 inches, step up to the XL Plus above.
FrostGuard NFL Cover pros and watch-outs
- Correct size for standard cars
- Mirror covers included
- Same frost protection as the XL
- Easy overnight fitting
- Team editions for fans
- Too small for full-size trucks and SUVs
- No wiper-specific coverage stated in this listing
- Exterior fitting in cold weather
- Must be removed before driving
FrostGuard NFL Cover: what owners report
- Owners report it fits sedans without excess fabric (listing feedback).
- Owners report frost-free mornings like the XL version (listing feedback).
- Owners report mirror covers save extra scraping (listing feedback).
FrostGuard NFL Cover: who should not buy
Skip this if you drive a full-size truck or SUV; the XL Plus above is the right size.
FrostGuard NFL Cover: pair it with
Pair it with a rear defogger repair kit for all-round winter visibility.
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Shake snow off before folding it away, or it soaks the boot. See all-season tyres for winter driving prep.
Spec comparison
Side-by-side specs from the maker listings. Unpublished figures are shown as Not published, never guessed.
| Specification | Permatex Defogger Repair Kit | Permatex Tab Adhesive | FrostGuard Plus XL |
|---|---|---|---|
| Form | Repair kit | Tab adhesive | Winter cover |
| Size / fit | Universal | Universal | 68 x 41 in XL |
| Part number | 09117 | 21351 | 53325 |
| Mechanism | Conductive paint + adhesive | Conductive adhesive | Security panels |
| Material | Acrylic + silver | Weather-resistant | Polyester + PVC lining |
| Repair / protection | Grid + tab repair | Tab repair only | Frost / snow |
| Cure / use | 24-hour cure | Per instructions | Overnight exterior |
| DIY level | DIY repair | DIY repair | Full front coverage |
| Contents | Kit | Kit | Mirror covers incl. |
| Check Price |
| Specification | FrostGuard Sunshade | FrostGuard NFL Cover |
|---|---|---|
| Form | Sunshade | Winter cover |
| Size / fit | Standard | 60 x 40 in standard |
| Part number | 53240 | NFL standard |
| Mechanism | Reflective | Mirror covers |
| Material | UV-blocking | Winter fabric |
| Repair / protection | Heat / UV | Frost / snow |
| Cure / use | Exterior use | Overnight exterior |
| DIY level | Windshield coverage | Windshield coverage |
| Contents | Security flaps incl. | Mirror covers incl. |
| Check Price |
Installation and repair basics
For grid and tab repairs, work in mild temperatures — the Permatex guidance centres on roughly 50 to 75 degrees Fahrenheit — on clean, dry glass. Mask precisely, apply thin coats, and keep the car dry and unused until the cure completes.
For covers, fit on a clean windshield before frost or sun hits, secure flaps and panels, and remove before driving. A cover left on a driven car is a hazard, and a wet cover packed away grows mildew.
For electrical diagnosis, check fuses, relays, and switches with the maker’s wiring diagram. See defroster accessories under 100 and windshield covers compared for related reading.
Safety essentials
- Never work on a defogger circuit with the ignition on unless testing requires it.
- Keep adhesives and paints away from eyes, skin, and children.
- Do not use a defogger on cracked glass until it is inspected.
- Remove all covers before driving; never drive with a covered windshield.
- Do not scrape a frozen windshield with metal tools.
- If glass is damaged, see a professional before any repair.
Three useful companions from this guide, each with its own button:
Permatex Complete Rear Window Defogger Repair Kit 09117 — For grid repairs in this guide.
FrostGuard Plus Winter Windshield Cover XL — For winter prevention in this guide.
FrostGuard Sunshade for Car Windshield — For summer heat protection in this guide.
Troubleshooting
| Symptom | Likely cause | Fix |
|---|---|---|
| Grid line still dead | Paint too thin or cure cut short | Re-prep, reapply, cure fully |
| Tab falls off again | Dirty bonding faces | Clean both faces; re-bond |
| Whole grid dead | Fuse, relay, or switch fault | Test electrics; see a shop |
| Cover blows off | Flaps not secured | Secure every panel and flap |
| Cover sticks to ice | Fitted after frost formed | Fit before the freeze |
| Sunshade will not stay | Flaps not closed in doors | Close flaps fully each time |
Who should NOT buy these
Electrical faults: no repair kit here fixes fuses, relays, switches, or wiring. Diagnose electrics first, or the kit will look like it failed when the fault is upstream.
Garage-kept cars: winter covers add nothing indoors. Spend on repair kits or sun protection instead of overnight covers.
Cracked glass: defogger repairs do not make cracked glass safe. Get the glass inspected and replaced if needed before any electrical repair.
Wrong-size covers: a cover that does not match your windshield wastes money twice — once on the purchase, once on the frost it fails to prevent.
Final verdict
Best Overall: Permatex 09117 — the complete grid and tab repair. Check Price
Best for Detached Tabs: Permatex 21351 — the targeted tab fix. Check Price
Best Winter Cover: FrostGuard Plus XL — full protection for big vehicles. Check Price
Best Sun Protection: FrostGuard Sunshade — heat and UV defence. Check Price
Best Team Edition: FrostGuard NFL Standard — the right size for cars. Check Price
FAQ
Why is my rear defogger not working?
Common causes are a blown fuse, failed relay or switch, broken grid lines, or a detached tab. Test the electrics first, then inspect the grid and tabs before buying a repair kit.
Can I repair a broken defogger grid myself?
Yes, for individual broken lines: the Permatex 09117 kit uses conductive paint to bridge the break. Clean masking, thin application, and a full 24-hour cure are essential.
How do I fix a detached defogger tab?
Use a conductive tab adhesive like Permatex 21351: clean both bonding faces, bond the tab, and let it cure per instructions. It restores the electrical connection, not just the physical joint.
Do windshield covers really prevent frost?
Yes, when fitted before the freeze: the cover takes the frost instead of the glass, and you remove the cover with the frost on it. Fitted after frost forms, a cover cannot help.
What size FrostGuard cover do I need?
Measure your windshield. Standard 60-by-40-inch covers suit cars and small SUVs; XL 68-by-41-inch covers suit larger vehicles. Oversized covers flap; undersized ones leave glass exposed.
Can a sunshade protect my dashboard?
Yes: reflective shades cut UV and interior heat, which slows dashboard cracking and fading. They work best with regular use, not occasional use.
How long does a defogger repair last?
A well-prepped, fully cured repair can last years. Rushed cures, dirty surfaces, and physical damage to the repaired line shorten life sharply.
Will a defogger repair work in cold weather?
Repair work prefers mild temperatures around 50 to 75 degrees Fahrenheit per maker guidance. Cold, damp glass gives poor bonds; work in a garage when possible.
When should I see a professional?
For full-grid failure, wiring faults beyond fuses and relays, cracked glass, or repeated repair failures. A shop can test the whole circuit and replace glass if needed.
Sources
- Permatex 09117 listing (ASIN B000ALBZJY)
- Permatex 09117 retailer spec (O’Reilly Auto Parts)
- Permatex 21351 mirror (ASIN B000HBGKWE)
- FrostGuard Plus XL listing (ASIN B09J65CFHL)
- FrostGuard Sunshade mirror (ASIN B08YWTPG1H)
- FrostGuard NFL cover listing (ASIN B01EX9GCXW)
- Permatex Windshield Repair Kit mirror (ASIN B000ALJ4MY)
- Permatex 09117 six-pack mirror (ASIN B0068FV73A)
- Permatex Windshield Repair Kit syringe mirror (ASIN B000HBI9XW)
- FrostGuard Plus XL alternate listing (ASIN B09J65CFHL)
By Leo, Founder, WinchInsider
Leo covers automotive gear with a research-first approach: maker specifications checked against owner feedback, so readers can buy with confidence.
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- About WinchInsider
Top pick: Permatex Complete Rear Window Defogger Repair Kit 09117