Healey Journal

A Buyer’s Guide: Criteria for Buying a Rustbucket: Potential Electrical Faults

9)  The Electrical System.  The electrical system seemingly suffers as much from its age as anything else on the Healey.  Thirty-five plus years of wet weather, road use and corrosion will make many of the connections less than reliable. Loose connections may cause any number of problems and can be very difficult to assess and remedy, poor earths in particular- and “good” earths where they’re not wanted (short circuits!) can make owning a classic car a nightmare. Even when new Lucas electrical components were not always considered the most reliable.

a)  Wiring: the old wiring harness was well due for replacement for it was showing its age and the sections routed beneath the car along the chassis rails were showing areas where the insulation had been abraded and the whole seemed irremediably susceptible to shorting out. Since the car will be completely rebuilt the replacement of its old wiring harness with a new one is also the most sensible option. A new harness may also include higher capacity wiring if desired and include wiring for spotlights and electrical fans etc. not originally used. The standard reproduction main harness may be bought for roughly £100, with sub-harnesses separately available for the overdrive and trafficator. The installation is a major job, as can be seen in a discussion of that work.

b)  Battery: My car didn't have a battery and even if it did the years needed/taken to rebuild all the rest would have made it useless. A new one will be acquired once it is needed. And given that the wiring will be completely replaced, with new switches and an alternator there's virtually nothing to concerned about for the battery. I'll need to get its polarity right, but that ought not to be too difficult. Of potentially greater difficulty is the battery cut-off switch used to ground the battery. The switch is susceptible to failure and irregular functioning and may compromise the whole of the electrical system's operation.

c)  Generator: The car was missing its original generator. The mounting brackets were still there, which was important because the cast one used as a cover for the valve lifter gallery can be difficult to find. The generator may be checked physically for any apparent damage or problems, most particularly that its bearings are not noisy or loose. Its output can also be checked as per manual specifications. The voltage regulator can also affect generator operation and can/should be checked. I'll replace the generator with an alternator and change the polarity too.

d.) Switches: The switches were almost all missing- the only one left was for the trafficator turn signals. The hydraulically operated brake switch was still there but would be replaced as a matter of course. All the switches would be replaced since I'd decided to upgrade the dash with more switches for a number of other upgrades and enhancements.

e.) Fuses: The original complement of fuses consisted of just two to protect everything. This seems a pretty limited amount of protection and users have added in-line fuses elsewhere (for the rear licence plate light, radios, etc.) for additional security. There's little that can go wrong with the fuses themselves or their housing. I intend to substantially upgrade the fusing to allow most circuits to be individually protected, and for my wiring harness to be adequately sized so that even a direct short would not cause problems.

f.)  Relays: The original Healey uses just one relay for the overdrive. That may be checked easily enough. But as part of my intended upgrading of the car I'll introduce additional relays for the lighting. These will allow the use of much stronger lights without passing high currents through the dash switches.

g.) Lights: Most of the lights were missing. The headlights remained, but were of little use since they focus the wrong way for UK driving. Other lights were there but showed their age; thus a full complement of new light housings and lens were obtained. Again, there is relatively little to go wrong with the lights- the usual problems with loose connections and poor grounds are a concern. Similar the lens should be checked for damage and cracks that would allow moisture in. If that happens the lights might not short out but be affected by corrosion in their sockets.

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Copyright © 2005 James M. Wilson All rights reserved.