Ford Solenoid Hot Start installation instructions, Mark Henry's method Options

[Mark Henry]

Because this comes up so often I decided to make a tutorial on how I install the Ford solenoid.

The Ford solenoid fixes the common hot start problem of Bosch starter solenoid and it also reduces the load on the ignition switch. Although these instructions are for the 914 all aircooled VW's and Porsche often suffer from this problem and with minor changes this can be done to any car.

The issue occurs because the Bosch starter solenoid needs a full 9 volts to kick in. The combination of age, heat, corrosion, many connectors, a small ignition switch and wiring running to the dash and back can degrade the volts to less than the 9V required.
The Ford solenoid only needs about 3 volts for the 12V version and even less for the 6V which for our purpose works no problem.

My installation drills no holes in the car, not a single factory wire is cut, no in-line fuses, fully reversible and simple with no added bullshit.

Please this is not a discussion on if you prefer the wimpy (IMO) Bosch horn relay, want to cut and hack in a new wire or believe throat singing Vajrayana chants is a better method, start you're own thread.

Of course as with any electrical trouble shooting the first order of business is always clean all of your grounds and make sure the chassis to transmission ground strap is in place and in good condition.

I'll start right away with the money shot of the completed installation to show how clean this can be done.

[914GT]

A few more things to consider...
I like to use wire with a high-temp insulation around the engine. Some of the primary wire from the local auto store has PVC insulation that can melt pretty easy so make sure it can't get too close to hot parts. I like Teflon insulation, or maybe put heat shrink tubing over the full length for extra insulation.

I don't trust crimp terminals for anything high current or vibration. For some extra reliability you can wick some solder into the terminals.

The protective caps on the big terminals is really a good idea not just in case the relay came loose. An exposed terminal to the battery can be dangerous if you accidently got a wrench or screwdriver across it. I know someone who got his watch band on a starter solenoid terminal and it took a long time for the severe burn on his wrist to heal up. Of course he shouldn't have had a watch on in the first place.