Replacement Guide for the 1966 Fargo D110 Pickup Speedometer Cable
Address a bouncing or dead speedometer needle in your classic Fargo pickup.
- A bouncing needle or dead speedometer is most likely a failed speedometer cable.
- New aftermarket cables from brands like ATP and Pioneer are the only practical replacement option.
- Verify the cable length (typically 83 inches) and connector sizes (7/8" and 5/8") before purchasing.
- This is a simple, DIY-friendly repair that can be completed in about an hour.
Is Your Speedometer Cable Failing?
A faulty speedometer cable is a common issue on vintage trucks like the 1966 Fargo D110. Because the Fargo is a rebadged Dodge D100, parts and common issues are nearly identical. Symptoms of a bad cable are usually straightforward and point directly to the cable itself.
Common Symptoms:
- Bouncing Speedometer Needle: The most common sign of a problem. As the internal cable binds and releases, it causes the needle to jump around erratically instead of showing a steady speed.
- Inaccurate or No Speed Reading: If the inner cable snaps, your speedometer will stop working entirely, remaining at zero.
- Screeching or Whining Noises: A dry or worn-out cable can make audible noises from behind the dashboard as it struggles to rotate within its housing.
Is it the Cable or the Gauge?
If your odometer is still working but the speedometer isn't, the problem is likely inside the speedometer head itself, not the cable. However, if both have stopped working, the cable or the drive gear in the transmission is the most likely culprit. A simple test is to disconnect the cable from the back of the speedometer and spin the inner core with a drill; if the gauge moves, the gauge is fine and the cable is the problem.
Choosing a New Aftermarket Cable
For a 1966 vehicle, finding a New Old Stock (NOS) OEM speedometer cable is nearly impossible. The market consists of new aftermarket parts, which are the most practical and recommended choice. Brands like ATP and Pioneer Cable are standard service-grade replacements that are widely available.
Reviews for these brands are generally positive but highlight the importance of checking specifications before ordering. Fitment issues like incorrect length or wrong thread sizes can occur, so confirming details is key. For the 1966 Dodge D100 (the Fargo's counterpart), a common replacement cable is 83 inches long with a 7/8" nut at the transmission and a 5/8" nut at the speedometer. Always measure your old cable if possible.
Pro Tip: Before installing a new cable, it's a good practice to lubricate the inner core with white lithium grease or a dedicated cable lubricant. This ensures smooth operation and a longer service life.
Aftermarket Speedometer Cable Cost for 1966 Fargo D110
| Part Type | Price Range |
|---|---|
| New Aftermarket Speedometer Cable | $16.75 - $18.64 |
| Shop Labor | $50 - $100 |
Prices are estimates and may vary based on location and supplier.
Frequently Asked Questions
Why is my speedometer needle bouncing?
A bouncing needle is the classic symptom of a speedometer cable that is old, unlubricated, or kinked. The inner cable is catching and releasing inside the housing instead of spinning smoothly.
Can I replace the speedometer cable myself?
Yes, this is a very DIY-friendly job for a home mechanic. It requires basic hand tools and access under the truck and dashboard. The most difficult part is often routing the new cable through the firewall. Taping the new cable to the old one before pulling it out can make this process much easier.
Are there any recalls for the Fargo D110 speedometer cable?
No. There are no recalls or technical service bulletins (TSBs) from the NHTSA related to the speedometer cable for the 1966 Fargo D110 or its Dodge D100 equivalent.
Should I buy a Pioneer or ATP cable?
Both Pioneer and ATP are standard aftermarket brands that produce functional replacements. Neither is considered a premium brand, but they are reliable options for a vehicle of this age. The most important factor is ensuring you order the correct part with the right length and fittings for your truck.
Technical Specifications
Common Length: 83 inches. Transmission-end fitting: 7/8" threaded nut. Speedometer-end fitting: 5/8" threaded nut.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.