Body and Engine harness question

[coppertop666]

So I have a 65 Monza PG and my engine harness has its share of previous owner gremlins so I am looking to replace from the engine forward to the fuse box. Also since I am in the process of adding an electronic fuel pump with a tach signal safety switch, my thoughts were to use a 65 corsa body and engine harness instead of the monza PG harnesses so I can have the tach signal right where I want to mount the safety switch under the dash.

My dilemma is, and I can't seem to get a straight answer, regarding the neutral safety switch/back-up lighting for the PG being different than the std transmission. My question is, If i replace only the engine and main body harness but keep the original fuse and instrument harnesses, is that doable regarding the factory neutral/reverse lights? Will everything still work as planned then I can just tie in the tach signal from the coil to the dash using the corsa harness?

Any help/advice would be appreciated, thanks.

[steve57]

It appears, after studying the combined wiring harness diagrams posted in the DIY section, that you would have to hack the new
Corsa harness to make your backup and neutral switches work. If you’re going to buy new harnesses, why not just pull a new wire for tach signal along with it?

[bbodie52]

When I combined the shop manual diagrams for the Corsa and the Monza, there was only a single group of diagrams in the 1965 Corvair Chassis Shop Manual that attempted to cover all variations (Corsa vs. Monza/500) in a single set.

It is impossible to tell when studying the diagrams just how much of the physical wire has been omitted in the Monza/500 harness. For example, the 20 Gauge Brown (20 BRN) wire from the ignition coil to the engine compartment 12-pin multi-connector may not actually be present in the Monza/500 engine compartment, but the 20 BRN wire on the other side (firewall side) of the multi-connector to the two-wire connector around the dashboard may still be present in the Monza — even if it is not in-use. The other wire (20 B/LG) is for the Corsa temperature gauge thermistor. It is not needed in the Monza/500, but is it still physically there? Would it have been cheaper to omit it from the Monza/500, or to put it in all Corvairs to simplify inventory and assembly?

I know the short instrument panel harnesses are different and unique to the Corsa or Monza/500 instrument panels. But without physically looking and inspecting a Monza (which I don't have access to) I do not know if the long (Main) harnesses are different or the same.

Left-click the image to enlarge it for better viewing or "Pan & Scan"...

1965 Corvair Monza Full Schematic

Note that the Corvair factory parts catalog only shows one part number for the 1965-66 Body Wiring Harness (Main) (highlighted in RED). Different smaller harnesses are shown for the 1965 and later Corsa and Monza/500 Instrument Clusters and Instrument Panels (with and without A/C) (highlighted in BLUE). This may indicate that a single main harness covered all variations of 500, Monza, and Corsa, but smaller sub-harnesses were built for the Corsa or Monza/500 instrument clusters and panels. The front trunk harness was also apparently of a single design and part number (Forward Lamp). Notes 1, 2, and 3 also talk of customizing, cutting, and splicing the harnesses, as needed. You may discover that the main body harness is essentially the same for all 1965-1967 Corvairs. It may already contain most of the wires you need. Only a short wire from the coil to the 12-pin multi-connector in the engine compartment may be needed for your tachometer sensor, and another short wire may be needed under the dashboard.

Wiring Harnesses - Parts Catalog

I have provided a lot of wiring information below...

Reference Section: CORVAIR COMBINED WIRING SCHEMATIC DIAGRAMS

viewtopic.php?f=225&t=12968


I would suggest looking over the attached Corvair wiring harness listing from M&H. It shows numerous small specialized sub-harnesses for special features, but only a few main and front (trunk) harnesses for 1965-1966. It seems to differentiate between Automatic and Manual transmission cars, but not necessarily between Corsa and Monza. I believe M&H builds the harnesses sold by Clark's Corvair Parts. It might help you to telephone M&H to discuss your specific needs so you can determine just what you need to order.

Here is a second source for Corvair wiring components...

» Thu Sep 03, 2015 12:46 pm

I'm an electrical person and I just wanted to say I had a great experience with M&H Electrical Fabricators in the Los Angeles area...

...Clark's sells M&H wiring harnesses and as far as I can determine M&H is the ONLY supplier that makes ALL the Corvair harnesses, even the one wire with connectors for the Spyder/Corsa thermistor (drives the temperature gauge).

I stopped by M&H's place of business and they were very helpful (I'm modifying one of their harnesses) and knowledgeable. I've used their harnesses in both my cars and fit and function is excellent.

M&H makes harnesses for lots of cars, but there commitment to the Corvair is worth noting. There are other suppliers, but over the years I've seen a number of so called "Corvair" wire harnesses from other suppliers that were incorrect or badly assembled that caused owners problems.

M&H Corvair Wiring Harness Catalog.pdf

M&H Corvair Wiring Harness Catalog

(849.15 KiB) Downloaded 157 times

http://www.wiringharness.com/

Mailing Address:

M&H Electric Fabricators, Inc.
13537 Alondra Blvd.
Santa Fe Springs, CA 90670

e-Mail Address: sparky@wiringharness.com

Sales and Customer Service: (562) 926-9552
Technical Support: (562) 926-9562
24 Hour Fax Line: (562) 926-9572

Repro Wiring Harnesses for America's Muscle Cars

M & H Electric Fabricators manufactures a complete line of exact reproduction wiring harnesses, battery cables and switches for Classic GM, Chrysler and AMC Muscle Cars.

All of our harnesses are hand assembled to original OEM specifications to ensure a perfect fit in your classic Muscle Car. Wire gauge, length, color and tape are exactly like stock original down to the last detail. Our rigid Quality Control Standards ensure that the harness you receive will look, fit and function as original. In fact, we are so confident in the quality of our harnesses that we offer a 100% satisfaction guarantee.

Just "click" around our web site for a while and see everything we have to offer. You can place an order, view any of our catalogs on-line or request a catalog via snail mail. Be sure to check out our FAQ page, it's loaded with answers and helpful tips.

In addition to servicing the Classic Muscle Car market, we also manufacture custom harnesses, pigtails and wiring assemblies for Original Equipment Manufacturers (OEM) as well. Some of our markets include: Automotive OEM, Performance Automotive Aftermarket, Heavy Truck and Bus, Farm Equipment, Marine and Industrial markets. Check out our list of customers.

We can build pigtails or harnesses to your print or help you design. Our extensive inventory of thousands of hard-to-find connectors and terminals (including discontinued GM part numbers) is unmatched in the harness industry. We specialize in low volume harness assemblies, pigtails and prototypes. Wire marking and printing is available, and our automated processing equipment ensures quality every step of the way.

Also consider...



http://www.ronfrancis.com/

Ron Francis Wiring
(a.k.a. Wire Works)
200 Keystone Road, Suite #1
Chester, PA 19013

INSTRUCTIONS FOR CALLING US
Toll Free: 800-292-1940
Local number: 610-485-1981

To place an order or ask questions pertaining to placing an order, hit Option #1

To ask technical questions in reference to a product that you already own, or what you may consider an extremely technical question, and return authorizations, hit Option #3

To request our latest printed catalog to be mailed to you, hit Option #2

Our shop is open Monday through Friday from 8:00 a.m. to 4:30 p.m. Eastern Standard Time. Sorry, but we are not open on the weekends. We do not have a showroom, but do allow customers to pick up their product from our location. If you are standing in our Pennsylvania location, you will pay Pennsylvania sales tax (6%) so weigh the benefits of shipping versus tax (plus the cost of gasoline) before you make the trip. We love to see our customers, and their cool cars, but we're not always worth the trip...

Please call for exact directions. We are located at the intersection of Rt. 322 (Conchester Highway) and Interstate 95 (near the Commodore Barry Bridge) on the Upper Chichester & City of Chester town lines, on a dead-end street that appears on both sides of the highway, at an interchange.

Their catalog is available for download at their Web site.

[coppertop666]

Gentlemen thank you for your replies. Brad, as always, lots of detailed information and I appreciate it every time.

After looking everything over I decided to just replace the harnesses with the original ones instead of that from a Corsa. I think in the big picture, like Steve stated, it's probably easiest to just run the additional wire for the tach signal then to try and play around with something that is not meant for the car.

Thanks again

[CorsaCharlie]

I mapped out the pin connections in the 1965 Main Body Wiring Harness (also posted elsewhere as "MainBodyWiringHarness")

Probably similar to other late model years, with exceptions for additional features in later years, such as "Park Brake Warning" light" etc.

Personally, I number them 11-16 on the left and 21-26 on the right (not shown) for less confusion when continuity testing.

I can't help but wonder why they didn't build this harness with pins matching either end, where possible?

I also "titled" this post as "MainBodyWiringHarness" because searching for multiple words gives too many irrelevant results, so to find this can search for "harness" or "WiringHarness" since "Wiring Harness" (with a space) results in every post with either word!

[flat6_musik]

I am curious about your tach signal safety switch idea. Is the tach signal going to activate a relay to do this?

[coppertop666]

I am curious about your tach signal safety switch idea. Is the tach signal going to activate a relay to do this?

This is the one I am installing - http://www.revolutionelectronics.com/Fuel_Pump.html

There are a few other types out there (inertia switch, oil pressure)but this one made the most sense to me. Here is what Clarks offers - http://www.corvair.com/user-cgi/catalog ... IN&page=66

[flat6_musik]

I like it, especially the 3-second pump-on at start up feature!

[County98]

I installed the American Pi one. Car isn't running yet, but I liked the idea also.

Sent from my SAMSUNG-SM-G891A using Corvair Forum mobile app

[bbodie52]

I'm still not convinced that an electric fuel pump is the best — or most reliable — option. An electric fuel pump that is properly designed, well-built, and properly volume and pressure regulated can certainly provide years of reliable service. But an electric fuel pump remains a mechanical pump system, driven by an electric motor instead of an engine crankshaft cam-driven push rod. The Corvair mechanical fuel pump is not in any way driven by an unreliable mechanical system. Nor is it complex — with two mechanical valves, a fixed-pressure spring, and a few diaphragms. The internal diaphragms are well-protected in an enclosed environment and seldom tear or rupture. The pump must form a vacuum to pull the fuel the length of the car, so a vacuum leak between the fuel tank and the pump in either rubber fuel line can be its "Achilles heal". An external pressure regulator is not usually needed, if the internal spring is correct to produce a correct output pressure.

1,786,234 Corvairs were produced in the USA by Chevrolet between 1960 and 1969. Many are still running after approximately 50-60 years, and of those still running the majority are still pumping fuel to the engine using the originally designed mechanical fuel pump — quite a few running the original factory-installed pump!
That constitutes a pretty-good long service operational reliability test. If the pump does not malfunction, it requires almost no maintenance. Keeping the feed and pressure lines leak-free is the main service check.

The Facet electric pump shown below has a good reputation for reliability. The pump should be installed near the fuel tank. It can still malfunction, and with the added wiring, plumbing and safety devices adding complexity, there are more possible points of failure than the mechanical pump system. Troubleshooting/repairing a failed electric pump system can be a little-more complicated than troubleshooting and repairing a mechanical pump system.

The electric fuel pump controller shown below appears to be a well thought-out solution for safe operation that provides both electric fuel pump cutoff safety and initial pump priming without all of the added complexity of developing the plumbing for an oil pressure safety switch sensing point and a lot of added rear engine compartment wiring. Most of the wiring could remain under the dashboard and in the front supporting the electric fuel pump were it should be — near the fuel tank. For non-Corsa/Spyder installations, a tachometer pulse sensing wire would have to be routed to the ignition coil negative terminal. (The main vehicle wiring harness may contain much of the needed wiring. A short lead from the coil to the engine compartment multi-connector and a connection under the dashboard may be all that's needed).

The other thing to consider...

$47.42 + $64.99
= $112.41

= $65.55



Fuel Pump Controller
This universal electric fuel pump controller is designed for cars and trucks being upgraded from a mechanical fuel pump to an electric inline or in-tank fuel pump.

• Pump only runs if there is a tach signal from the ignition.
• Primes the pump for three seconds at initial key-on.
• Includes a 7.5 amp circuit breaker.
• Includes an internal relay.
• Includes 15 feet of 16 gauge wire to energize the fuel pump.

One year warranty
30 day Money Back guarantee
$64.99 PN 12003

http://www.revolutionelectronics.com/Fuel_Pump.html
http://www.revolutionelectronics.com
Cypress, California 90630

https://www.amazon.com/Revolution-Elect ... nics+12003

This Fuel Pump Controller is a “must have” for any electric fuel pump equipped muscle car. It monitors the tach signal to limit when the fuel pump can operate. When the key is first turned on, the fuel pump is allowed to operate for three seconds, priming the fuel system. After these first three seconds, the pump is only allowed to run when the engine is running; if the engine stops, so does the fuel pump. No plumbing into the oil lines or adding an extra priming button under the dash. (If you are converting to an in-tank pump, be sure to check out our Power Isolator.