Over a year ago I installed some auxilliary driving lights on my '80 GT, using the fog-light ports on the grill for the location of the new lights. I wired the aux lights directly into the high-beam wiring on the existing headlights, so that they come on any time the high-beams are activated. The lights have worked fine for over a year, but I thought I would ask for any comments on this sort of renegade wiring application. Am I living on borrowed time here, or is there nothing to worry about. My concern is having wired the lights without the use of an additional relay. Just curious - electrical aspects are definately not my long suite.

Thanks

JB

If your '80 lights are wired like those on my '83 and '84, the headlight switch carries the entire current of the headlights. I have had the switch and the plastic connector to the switch overheat and melt requiring replacement. This would be even more likely with the driving light current added. I would wire in a relay controlled by the headlight switch to control current (using 10 or 12 guage wire)to the dimmer relay. That way the dash switch only carries only the small relay current. I plan to do this on my cars. My '86 and '88 come wired with this relay and I like it much better.

Actually, that was one of the reasons for my initial post. I had that very problem occur. I have seen deterioration in the plastic connectors at the lights as well, but removed them and then plugged the terminals in with some electrical tape insulation which seemed to resolve the issue. Same is being done at the switch - but the point has been made that I need to incorporate a relay in the mix here.

Appreciate all of the help!

JB

JB,

I'm afraid you are living on borrowed time. Even the original fog lights on the GT had a separate relay. The electrics on the GT are not overbuilt and that headlight relay is no spring chicken. Besides, not being able to turn off the driving lights independently cold get you in trouble with the law.

Skip

'83 242TI

'93 850GLT

'96 850R

Thanks Skip,

A couple of follow-ups. No real concern with the legal aspects, but what would be the best way to address the impending issue - can I resolve this by upgrading the existing headlight relay? If so, what would be best avenue be there. Second, in the event of a catastrophic failure, would I be looking at the existing relay failing, and in turn the lights going out, or something else.

Thanks again for your help.

JB

Re:

>Second, in the event of a catastrophic failure, would I be looking at the existing relay failing, and in turn the lights going out, or something else.

All of the above plus a fire ignited by overheated wiring.

Put a relay in the loop. Let the relay be energized from the lead that now lights your driving lights. Connect a #10 wire from the battery through a 10-amp in-line fuse (Radio Shack) to the relay contact #30 and Have relay contact #87 go to the lights.

Get a relay from a junk yard, several, with a 20amp rating. The power windows, central locking, and pre-1985 Fuel and System relays will work. Get a base, too, with leads cut long enough to solder on connections.

Good Luck,

Bob

:>)

Thanks Bob, just a quick clarification question. The driving lights are currently run in series off of their corresponding high beam. Instead of introducing two relays (one on each series of lights - ie high-beam/dr light)can I introduce a relay between the light switch and dimmer switch and achieve the same results? Or is there a better location? I have a 30amp relay I am considering using, it cam with the original driving light kit.

Thanks very much for your help

JB

So right now you get high beam and driving lights on or off togther, right? Last car I had with driving lights I found places where I liked to have high-beam only. Especially when using the high beam flasher signal, so I had a separate switch for the driving lights. BTW the D-lights were great for west Texas highway trips.

Whether you use one relay or two is your call. The problem is that the wire from the battery through the headlight switch to the headlights now carries the full current. That may be OK for just the headlights, but adding the draw for the D-lights will - as you saw - overheat things.

Plus, you get a voltage drop and therefore less than maximum light output.

The high beams are not incorporated into the bulb failure warning system. You could mount one relay under the hood, near to the stepping relay rail over by the battery. Tap into the high beam wire to relay terminal #85, grond #86, that will do the coil. Then run the #10 wire from the battery to the relay #30 and from #87 or #87b to both D-lights. Stick in an in-line 10amp fuse, too.

The relays I mentioned in the earlier post have a standard terminal number ID system. The coil is between #85 and #86. The armature is #30, and it contacts #87 or #87b when closed, #87a when open. Relays with only 4 terminals do not have the normally open contact, but you don't need that here.

Good Luck,

Bob

:>)

Thanks Bob,

Really appreciated. The D-lights are tapped into the high-beams directly on either side, so if I simply run the high beams through the relay will that suffice?

I appreciate what you were saying about the desire to have high beam/d-lights seperately, I debated that a bit, but decided to go with the straight d-light+high beam; it works well for me, certainly not everybody's choice, but I like it.

Thanks again for all of your help.

JB

The whole idea is to be sure that the wiring and devices through which current flows to the lights is adequate to carry the load. To be certain of that, you should put a relay in for each side. Then the contacts would be carrying the load for one high beam and one D-light, oughta be OK.

Having just one relay for all four lights would probably result in a voltage drop and heated wiring.

Good Luck,

Bob

:>)

There's also a concern about pumping extra current through the wires. I don't know what they're rated for, but in looking at the condition of most of _my_ wires (1982 245 wagon) that i've had to replace it isn't much. I would just install a new switch with relay. Or just a switch that is capable of handling the current.