Joe Cool Fan Relay Failure
One of the DeLorean's weaknesses is the Lucas relays, which can fail at any time. This will likely happen at the worst possible moment. Like when you're being chased by, say, the Libyans or something, in a mall parking lot.
Ask around the DeLorean community and most will tell you that only Concours cars use the original relays. Most will tell you you're crazy if you drive around on the original relays.
Well, call me crazy.
My DeLorean has 112,000 miles clocked, which is sorta medium-high in the DeLorean world. And I'm still going strong on the original Lucas relays. ODOC prez Kenny and Pat Mastroianni (yes, that Pat Mastroianni) have both been on my back to replace the relays. So it's kind of ironic that the ONLY relay to ever fail on me was the ONLY one I'd ever updated: the cooling fan relay.
There are a few fixes for the cooling fan relay. The most basic is a pair of wires used as a jumper. But it can melt and should only be used as an emergency fix. The DeLorean Motor Company and John Hervey (DAP) sell updated relays. Rob Grady's Fanzilla is no longer available.
The option I installed in 2009 was Joe Cool, made in limited numbers, and no longer available. It was available through the DeLorean Motor Company Midwest and McFly Motorsports for a while, for $175.
See it installed here.
Normally both fans kick on together, sucking huge amperage. While this is only for a second, the spike causes damage as the current runs through the circuit board. It melts the soldering, causing the relay to fail. You do not want your fans in cahoots with each other! What Joe Cool does is stagger them slightly, so one comes on before the other. This stops them from drawing too much current at once.
Unfortunately for me, my original failing fans draw such HUGE current that my Joe Cool failed while driving the car on a lengthy journey to DPI with friend Ken. Sitting in a traffic jam I watched in horror as my temperature gauge creeped past 220 and edged towards 260.
Joe Cool did not keep his cool. Joe Cool had let me down!
I warned Ken I was about to overheat and spill coolant all over the road. We unscrewed Joe Cool and discovered one of the two fuses had blown. Driving at high speeds to keep the air flowing through the rad, we escaped the jam and high-tailed it to the nearest Pep Boys where I purchased new 15 amp 3AG type fuses for less than 5 bucks. With a new fuse in place, Joe Cool was back to normal and the fans came on beautifully.
Let this be a lesson. Even the updates cannot be relied upon 100% of the time and a sane DeLorean owner will carry around a spare set of relays. Then there's me.
---------- Update June 2012: After DMCMW's visit I've learned why Joe Cool failed, and my fans are the culprit. My fans are beginning to fail, and as such are drawing too much amperage for the 15 watt fuses. Joe Cool is fine - I will have to replace my fans soon.