Insight headlights are flickereing randomly

[cowmeat]

My Gen-1 Insight's headlights have begun to randomly flicker off for a second and then back on. I say randomly, but it usually seems to be when I'm either slowing to a stop, or taking off from a stop. They only shut off for a second, then come right back on. It's both headlights, and possibly the taillights too. I haven't happened to have a chance to see it they go off too.

Has anybody had this issue before? I'm going to check all the ground straps, etc. . . . but I'm curious if anybody else has had this happen, and what the cause turned out to be.

[nemo]

Sounds like a good place to start. What about the condition of the 12v battery?

[jamesqf]

My first thought would be to check the switch, I've had similar problems on other cars that were traced to the switch.

From a quick look at the wiring diagram, it looks like switch to HL relays is the only common path, then there are separate paths from left & right HL relays to lights.

[cowmeat]

What about the condition of the 12v battery?

The battery is only two years old and for all appearances it's in great shape. As soon as I get an hour of free time at some point, I'll check the battery connections, wires, the ground straps, etc . . . . and if everything's legit, I'll pull the battery and have it tested.

If that fails I will order the turn signal switch. Apparently it was recalled back in the day, but I'm the fourth owner, so I have no idea if mine was replaced since Carfax isn't that specific.

For whatever reason, they didn't shut off at all this morning!

[dirtydave]

Sounds like a switch to me!

[Xist]

My lights used to pulse and Autozone said that it was a bad voltage regulator, which is contained inside the alternator, and a new alternator was cheaper than a rebuilt VR, except the new alternator did not fit until I took a hacksaw to it...

[user removed]

Only a switch defect could make them not shut off, ass-uming the circuits have not been buggered.

regards
mech

[jamesqf]

A weak 12 volt battery won't cause flicker, especially on the Insight, because 12-volt power is coming from the DC-DC converter. Easy to check this if you have a ScanGauge or similar. Set it to show voltage: when the DC-DC is active, it'll show about 14.4 volts, if it's just drawing from the battery (which it does sometimes) it'll be in the 12.X volt range.

You can get a situation where the DC-DC doesn't come on properly, and voltage will drop into the 11.X range. If this happens, you'll see headlights dim, and get (IIRC) the battery and brake warning lights lit up. Usually turning the switch off for a couple of seconds (while coasting) then back on would kick the DC-DC back on, but long-term fix was to re-balance the battery pack.

[cowmeat]

Nope, they don't dim at all, they just shut off, and come back on after like a second.
I'm leaning toward the switch being bad at this point. I think I'm going to order it today