Club 80-90 Forums

Unfortunately, all the stock main cables deteriorate and whilst a few frayed ends don't seem to make much difference, they do, particularly with respect to voltage drop.

Way before I replaced mine with thicker stuff throughout, I'd fitted a calibrated volt meter up front so I could monitor levels at varying conditions and as said many times, if nothing has been touched, its not unusual to see less than 11 volts at headlights - my findings at the time back that up. However you do things, theres no substitute for a clean, fat, bright cable front to back.

CovKid wrote:However you do things, theres no substitute for a clean, fat, bright cable front to back.

here here.

Got the relay fitted now, and the results are in.
Before I had 13.1v with the headlamps on, now with the relay fitted I get 13.2v, so a slight improvement in voltage although I am sad to say no noticeable improvement in light output from the headlamps.
With the heater fan on full the voltage drops to 12.6v, (previously 12.5v) which noticeably dims the headlamps. Need to look into this further to see where all that voltage is going.

Well, if you've not touched them, it'll be main cables. You would be astounded at just how much is lost in that run alone. Beefing it up all the way through (from alternator to dash) should sort it.

On mine, the original fusebox handles all the low amp stuff now, and a new supplementary fusebox handles, blower, fan and lights on a very fat cable (red in photo).

Relays help ofcourse but not much (if any) if you're still dependent on the stock 6mm cable that supplies fusebox. The relay in this instance would merely take the load off the wiper stalk and not much else. Likewise, adding a fat cable from battery to dash without starting at the alternator won't improve lights much either.

Replace main cables, fit relays for lights, and swap the regulator for a 14.5v one and you're there. Any other faffing under the dash is somewhat fruitless if everything is still running through the original 6mm cable. Its simply not up to the job if you want brighter lights.

The WIKI links to the cable upgrade mods are on page one of this thread.

Don't forget to wipe your headlights clean too

The other night could hardly see the road when looking for a right turning of a dual carriageway I know well. Problem was I just couldn''t see the right hand verge not helped by LHD. Stopped in a lay-by a bit further on after making my turn to check the lights and they had thick film of road muck on them so the lens not really focussing the beam on the road it was just lighting up the muck. Made a hell of a difference wiping it down. This is just the build up from a couple of days driving down the M25 in winter. If I look at most cars with modern projection lights on they don't really get affected by the road grime like the old units do. Think it must be the heat of the lamp baking the road film onto the lens. Used to have the same problem years ago when this sort of headlight common.

Still another job to add to the list - sort out the wiring to the lights! Usually ignore it as most of my driving is in the summer when nights are short and I am in places where my main beam is on most of the time and that seems fine.