I’m the proud owner of an '87 Acura Legend. It’s never had any major mechanical problems, but little things keep breaking on it. Lately I’ve noticed a minor electrical problem. When you switch the headlights on, the dashboard and taillights go out. They work fine when the switch is turned to the first position, for daytime running lights. I used to be able to keep both sets of lights on by turning the switch halfway between the first and second positions, but that doesn’t work anymore.
I’ve also had a couple of intermittent problems with instrument lights blinking or not coming on. I’ve checked all the fuses, but none were burned out.
I figure there’s a corroded contact in the headlights switch. It’s on the end of the turn signal arm that sticks out of the steering column. Unfortunately it will probably be necessary to take apart the entire column to get at it.
Is there anything else I should check before I have a bunch of expensive work done?
I figure you are right on about the switch but ALWAYS check for a loose connector assembly before replacing anything.
We have very complicated electrical systems in the tools we manufacture at work. Literally hundreds of cables in many different subsystems. Similar in scope to your car. 80% of all electrical problems we have, at least during protyping, are caused by loose connectors or wires not being crimped into the connector well enough.
Get a wiring diagram for the car first off. Look for loose or corroded contacts in the connectors at the base of the steering column, and then in the engine compartment if they go there for the lights. Then get a friend over that knows how to use a voltage meter to check for conitinuity and for proper function in the switch.
It’s a simple process that is very time consuming and about 50% effective. Those intermittant electrical things are a real bitch.
I had the exact same problem in a 78 olds way back when I was in college. It turned out to be a short in the steering column (it had one of those tilt wheel steering wheels, and I guess it got tilted one too many times and the wires wore through the insulation).
Shorts can be fun to find. One trick is that if you use a fairly high quality meter, you can measure between hot and gnd at various points. You’ll measure the resistance of the short, plus the resistance of the wire in between the meter and the short. When the resistance starts getting smaller you are getting closer to the short. The resistance of wire is pretty low though, which is why the $10 cheapie meter from radio shack won’t cut it. I’ve never gotten exactly to the short using this method, but I’ve narrowed it down to within a few feet, and with a few hundred yards of wiring in your typical car that’s a big benefit.