chuck v

Long Story that I will try to make short.

I am working on a friends 67 Mustang (Eleanor Clone) with a Kenne Bell Super Charged 302. The car was purchased from a private seller in California a couple of years ago. The car has a combination of old original wiring and new wiring for the Fuel Injected Motor.

Here is the issue I am chasing:

The car runs and drives great until you are sitting in traffic, like entering Good-Guys Events or Cruising Woodward Avenue, which I did this year (the car has all electric gauges,stereo equipment, electric antenna, and fuel injection)at 215 degrees on the temp gauge +/-, the engine shuts off like someone turned the battery switch off. Wait about 3-5 minutes, cools down a bit, and the electrical system comes back on and the car is ready to start again. The car has the battery in the trunk and also has a power amp wired to it. I can understand the car shutting down the motor to protect it from overheating, which it isn't, but for the car to lose all electrical power is perplexing.

It was suggested that I check the relays under the dash, as the old Mustangs have a few, to see if one is bad. That would be fine except this is an intermittent problem and there are 6 relays under the dash and 1 under the hood along with at least one circuit breaker that is in the fuel injection harness on top of the motor. Where does a guystart? These issues throw me for a loop!

I wrote down all the relay part numbers and I plan to go to Ford and get someone to look up the parts and tell me what is what.

Anyone have any suggestions, short of tearing the entire wiring harness out and starting over?

Thanks,

corvetteguy

Sounds like you have to carry a voltmeter with you
to diagnose the problem when it occurrs.

With the switch on car running measure each
fuse and write down voltage.
You might check other points of access.

When it fails again redo the measurements.

This might lead you to a after/installed shut off
relay.

chuck v

Thanks, I will try your suggestion and see what I find.