Do you make harnesses for pre 1955 passenger cars?

No, but most of the popular applications for these years are being manufactured by YnZ's Yesterdays Parts. You can reach them at (909) 798-1498.

I want to install an H.E.I. distributor?

All original "point type" distributors require no more than 9.6 volts (approximately) to operate correctly. Most GM cars use a "white cloth covered" resistance wire or a "ballast resistor" to reduce the line voltage to the coil from 13.7 volts (approximately, when vehicle is running) to the necessary 9.6 volts (approximately). The "white cloth covered" resistance wire or a lead from a "ballast resistor" must not be used to power a GM H.E.I. distributor. This is a common mistake, that will degrade performance of the ignition system. All GM H.E.I. distributors require full system voltage of 13.7 volts (approximately, when vehicle is running) to operate at peak efficiency.  

M&H has an easy solution. (click here)

If I convert to H.E.I. will my Tach still work?

Generally all pre 1972 tachs will work, however most will not read correctly. R&C Tach shop can replace the circuit board in your tach with a newer style board that will work correctly. You can reach them at (812) 284-2555.

I want to install an Internal Regulated Alternator?

External Voltage Regulators are becoming very difficult to find, and are not very reliable. We suggest using a genuine Delco internal regulated alternator for all applications.

The problem when converting from external to internal though, is adapting your original harness. Not only do you need to make sure the alternator will still charge the battery, but you'll want to make sure your gauge or warning light is still able to alert you when the system is not charging.

M&H has come up with an easy and inexpensive solution. (click here)

I am converting my car from warning lights to gauges, what all is entailed?

The two most popular models to convert from warning lights to gauges are 1967 to 1969 Camaros and 1970 to 1972 Chevelles and El Camino. NOTE: Factory schematics for gauge type cars are not available and were never produced by GM.

1967 to 1969 CAMAROS

Camaros can be converted by using one of our console gauge conversion kits. The kit is somewhat difficult to install and requires some electrical knowledge, however it is an economical way to adapt your original harnesses  to accommodate the console gauge set.

The preferred method of converting a Camaro to Gauges is to replace the Dash Harness, Forward Lamp Harness, Engine Harness and the Console Harness with gauge style harnesses. Although this is more expensive then our conversion kit, installation is quite a bit easier.

1970 to 1972 CHEVELLE & EL CAMINO

All 1970 to 1972 Chevelles require replacement of the Dash Harness to a gauge style harness. 1970 to 1971 models also require replacement of the Forward Lamp Harness to a gauge style. In addition, 1972 models require replacement of the Engine Harness to a gauge style harness.

For other models please call our tech department at (562) 926-9562.

The harness I received appears to be different than my original?

Everything should match your original harness perfectly. Please keep in mind that all harnesses are built using the most current GM revision. From time to time you may notice slight differences from your original harnesses. These differences normally do not affect fit or function. If you have any questions though, please contact our technical support line at (562) 926-9562.

Please do not e-mail us with technical questions or problems, you will not receive a reply. Call !!!

Where can I get a harness for my Street Rod or Roadster or Race Car?

For Race Cars, Roadsters, Street Rods and Custom Wire kits we recommend American Auto Wire. There extensive line of do-it-yourself kits are the best we've seen. They can be reached at (800) 482-WIRE.

Where can I get a harness for my Ford or Chrysler?

Some Ford wiring harnesses are available from YnZ's Yesterdays Parts. You can reach them at (909) 798-1498.

Chrysler harnesses are available through Year One, click here for more information.

Do you sell any Connectors or Terminals separately?

No, we only sell complete wiring harnesses. Connectors and Terminals are not available separately.

Do your harnesses include installation instructions, schematics or wiring diagrams?

Installation instructions, schematics and wiring diagrams are not included. It is suggested that you have a "Factory Assembly Manual" (if available for your model) on hand when installing your new harness. "Factory Assembly Manuals" (if available for your model) contain general overview schematics, as well as line drawings of how to route the harnesses in the vehicle. The Manuals are available for sale directly from us, or through your local restoration parts supplier.

A few of our specialized harnesses and kits do include instructions and schematics. These include: 1947-1959 Chevy Truck Complete Wiring Sets, Camaro Console Gauge Conversion Harnesses, GTO Rally Gauge Adapter Harness, Corvette T.I. Ignition Module, all Alternator Conversion Harnesses and a few others.

What is that Brownish/Black grease on my new harness?

Some of our Engine & Forward Lamp Harnesses utilize a special di-electric grease as original. The grease is smothered inside the bulkhead connector that mounts to the firewall. Do not remove this grease; it is a corrosion inhibitor. Do not allow the grease to come in contact with your clothing, as it will stain.

I am connecting my starter and I'm not sure which wire(s) go where?

The purple wire with the ring terminal goes to the S or Sol post on the solenoid. The other wire (if applicable) with the same size ring terminal goes to the R or Res terminal on the solenoid.

My harness doesn't match my schematic?

Don't be surprised, most schematics including those found in the assembly manuals are usually not 100% right (they are usually for a baseline car with no options). They usually fail to reflect wiring changes or additions due to optional equipment such as: gauges, consoles, automatic transmissions, Big Block engines etc. Unfortunately GM never produced schematics for cars equipped with these options (to the best of our knowledge).

ATO Style / New Style Fuse Boxes?

All of our 1958-1978 dash harnesses include fuse boxes that are set up to use Buss style (aka Glass type) fuses, as original. Our Classic Auto Fuse Series Dash Harnesses feature ATO style fuse boxes. Most 1979 and up vehicles used ATO style fuse boxes, which we include in most cases.
Note: Our 1979 & 1980 Corvette dash harnesses include the correct ATO style fuse boxes, as original.