Driver's headlight, left flasher problem - Honda Prelude Forum

KahnBB6 · 04-30-2008, 05:39 PM

I'm trying to diagnose this as much as I can before I turn it over to the dealer to look at. The car is a 2000 model.

Yesterday in the afternoon while I was out of town I noticed my left turn flasher on the dash began blinking very quickly. I pulled into a parking lot and began checking all my lights and blinkers. Despite the indicator blinking quickly, all the bulbs were working but the driver's side main headlight bulb was out. The high beams were both working.

I always carry H1 spares in the trunk so I tried replacing the bulb. The headlight still didn't come on. I wiggled the electrical harness going to that bulb and made sure the connection wasn't loose. Nothing. I did think the bulb receptacle looked very worn out. Perhaps this was the problem?

Since it was getting late and there wasn't much else I could do, I got by with the high beams whenever I absolutely needed them.

Today I went to a dealer and purchased a new bulb receptacle. I installed it with a good bulb but it still didn't cure the problem.

I checked the driver's headlight main fuse and it looked fine. Now I am noticing that the front left turn indicators are all extremely dim but the rear indicator on the taillight is still at full brightness.

I am not sure where else to go with troubleshooting at this point. Does anyone have any ideas?

Also, I might add that the car has developed a 2000-0 idle bouncing issue when the A/C compressor is on (IAC-V related?) which I will need to address soon. I can't imagine both issues being related but I thought I'd mention it in case there is a correlation.

Prelude1897 · 04-30-2008, 06:13 PM

be sure you pulled the correct fuse when looking under the hood. When you hit the hazzard button, were all 4 turn signal bulbs flashing?

Ludatic · 04-30-2008, 08:11 PM

Sounds like something's funky with your wiring. I don't recall the flasher circuit being tied in with the headlight circuit at all. Possibility you have a short in your multiplex control unit too, which the dealer would just replace and is damn expensive.

Did you install anything prior to this happening?

KahnBB6 · 04-30-2008, 10:10 PM

>>>Prelude1897 --- be sure you pulled the correct fuse when looking under the hood. When you hit the hazzard button, were all 4 turn signal bulbs flashing?<<<

I actually hadn't checked the emergency relay. It certainly is acting strange-- all the correct lights flash EXCEPT the driver's side flashers, which alternate with the rest of the lights on the other side. The rear flashers sync correctly but when each flasher is off the front parking light comes on.

Quote:

Originally Posted by Ludatic

Sounds like something's funky with your wiring. I don't recall the flasher circuit being tied in with the headlight circuit at all. Possibility you have a short in your multiplex control unit too, which the dealer would just replace and is damn expensive.

Did you install anything prior to this happening?

The car has an old Alpine alarm that is still wired up but it hasn't been used in a very long time.

I did damage the front fender, passenger side headlight and hood after losing control in a rainstorm early this month. I got the car back from the bodyshop little more than a week ago and experienced none of these problems upon receiving it back. Everything checked out when I inspected the work and the car drove normally.

What part(s) are involved in replacing the multiplex control unit and where is it located on the car? The vehicle has 120,000 miles and other than the alarm, which I installed in 2000, none of the wiring has been modified from factory spec. Is it a common thing to burn out on 5th gens at this mileage?

Thank you for your help guys!

Prelude1897 · 05-01-2008, 09:43 AM

There are 3 multiplex units. 1 on the driverside door, 1 behind the fuse panel on the driverside, and 1 behind the passangerside kick panel. All 3 are black boxes. Since you say you wrecked, make sure you don't have any cut or exposed wiring.

Ludatic · 05-01-2008, 02:42 PM

The multiplex control units generally don't fry unless something is wired incorrectly and is unprotected by the fuses.

huge possibility the bodyshop screwed up, most body shops are generally noobs when it comes to electrical wiring

when i had my front end repainted they screwed up my wiring pretty bad, but luckily i checked first

KahnBB6 · 05-01-2008, 07:00 PM

I had my old dealer look at the car today. What the tech came back with was a short in the ground wire to the driver's side headlight. It's going to take some hunting to find the source so I opted to keep the car over this weekend and bring it back on Monday.

Ludatic, I'm inclined to agree with you that it may have been something the bodyshop did. Even after I wrecked I had a shattered but fully operable passenger side headlight and I drove the car for about a week and a half in its compromised state without any of these issues cropping up. I might add that there wasn't any mechanical or frame damage to the car-- I wouldn't have done this if that were the case.

These issues only cropped up within seven days of getting my car back from the bodyshop. I'm going to visit there tomorrow and inform them of this.

Thank you for your help, guys. I wish it were as simple as a burned out relay or control unit.

freezingcoffee · 06-19-2008, 08:12 PM

sorry to dig up an old thread like this, but my driver's headlight is not working. Everything else is working, including the turn signals, and the pass. headlight. All the fuses are good. I want to point the problem to a bad ground somewhere. I used to have retrofits on the car, which ran off of a harness that was plugged into the pass headlight, so I didn't worry about this problem till now. When I first got my retrofit a couple years ago, the oem halogen high beams on my driver's side worked, but the fuse kept blowing on it.... maybe that can give a clue to what the problem is.

tlewis7507 · 12-12-2009, 11:02 AM

Did you ever get this headlight problem fixed? If so... what was the problem.

KahnBB6 · 01-10-2010, 11:49 PM

tlewis,

I just got back to checking my messages. Yes, I did get the problem repaired. It wasn't the multiplex control unit. The Honda tech found, as he originally predicted, a shorted ground wire (or maybe it was a + wire) to the driver's headlight. It took some time to find the right one with a multimeter. He got it and spliced a long portion of it that had gone bad. He didn't have to go into the firewall.

I've had no similar issues in the two years since.

Also, I always carried spare H1 bulbs because every 3-4 months or so that same headlight bulb would go out on me. I haven't had to deal with that old issue since he fixed it, so that suggests the seed of the problem probably predated my hydroplaning accident.

Whatever caused the wire to short out is beyond me. The car has been fine since the tech made his repair.

globalfeet · 08-11-2011, 04:20 PM

I had the same problem as Kahnbb6 and it turned out to be a bad ground as well.

symptom:
- driver side main head light out
- quick flashing left turn signal
- left turn signal green indicator on permanently

Instead of tracing the bad ground (no time) I ran a new ground. Splice the ground on the passenger side headlight connector and make an extension to the driver side. Cut the ground on the driver side headlight connector and extend the ground wire coming from the harness, not the connector.

Connect the extended driver side and the passenger side ground together. You should have something like a Y connection. Finally connect the new ground back into your driver side head light connector.

Not professional, but it worked for me.

KahnBB6 · 08-12-2011, 03:48 AM

That's an interesting fix. It's been a while and I don't have the car to reference any longer but from recollection a section of wire had to be cut out and replaced. I never found out if this is a common problem with 5th Gens but repairing the ground seems to have fixed the issue in my case.

Funny that you had the same issue. What mileage are you at? I don't remember at what mileage my issue began but it could have been as early as 100k but maybe not that soon. It finally got addressed at 120k.

Glad to hear you figured out a fix.

globalfeet · 08-17-2011, 06:56 PM

Mines a 99 base model currently at 180k. I found a couple post on the prelude forums that had similar problems, but your post gave the most info. Thanks for posting your experience and I hope this helps the next guy out.