Headlights won't work. NOT A BLOWN FUSE!

Mazda_Power · Post by **Mazda_Power** » November 30th, 2005, 3:08 pm

I'll test the wires now, I'll report after work!

Mazda_Power · Post by **Mazda_Power** » December 4th, 2005, 9:35 am

Guess what? Now all my interior lights are shutting off. It sounds like a solenoid/relay under the dash clicking on and off constantly. At one point when they were on, I pressed the brake and they turned off (voltage problem because of the brake lights??!). I checked the battery voltage with the engine running and I got 13.5 V. I should have over 14V. I'll check the batteries charge too in a bit. Also check the charges of the light relay.

Aaron

Mazda_Power · Post by **Mazda_Power** » December 4th, 2005, 10:20 am

Just checked the battery. 12.5V while not running. That should be good.

Mazda_Power · Post by **Mazda_Power** » December 4th, 2005, 1:08 pm

OK. I got 4.9V out of both the red and the orange wire for the headlight relay. Nothing out of the other two.

Grants · Post by **Grants** » December 4th, 2005, 3:48 pm

In the engine bay there should be a 30A "head" fuse.

Can you check the voltage on both sides of the fuse (with it still in)? Obviously you're losing votage somewhere and this is the most likely place. You should just replace the fuse anyway even if it looks ok just to be sure.

The wiring goes directly from this fuse to the relay so theres not much that could be wrong except the fuse or a bad joint.

I take it your using a digital multimeter. Unfortunately these aren't always best as you can get a voltage reading on it but as soon as a load is applied the voltage might "disappear". Your best off with a test light if possible.

Mazda_Power · Post by **Mazda_Power** » December 4th, 2005, 6:36 pm

Yeah, it is a digital multimeter. I do have a test light... somewhere. Thanks for keeping an eye on this thread despite how slow it is.

Mazda_Power · Post by **Mazda_Power** » December 4th, 2005, 7:33 pm

I THINK THAT THE GROUNDS MIGHT BE BAD. THE VOLTAGE IS OK, 12.5 WHEN KEY IS OFF, 13.5V WHEN RUNNING. IS THERE ANY CERTAIN GROUND I SHOULD CHECK? I'M NOT SURE IF I MENTIONED THIS, BUT I HAD SOME WIRES CROSS IN THE THE DRIVER'S SIDE FENDER WELL. I REPAIRED THEM ALL, BUT IS THERE A GROUND IN THERE PERHAPS?

Grants · Post by **Grants** » December 4th, 2005, 10:29 pm

Regardless of the grounds, there should be 12V at the RED wire at the relay. You really need to confirm a good 12V there first. (If it was a grounding problem from the headlights the relay should still operate.)

So we really need to work though it by:
- power to the relay
- relay operates
- 12v to the lights

Mazda_Power · Post by **Mazda_Power** » December 5th, 2005, 2:29 am

OK. I did some work tonight. I tested the original relay by appling a 12V source to it. It turned on (when either red wire was touched by the 12V source). So the relay works and the grounds on the headlights are OK. When I checked the voltage on the HEAD fuse it was 12V on one side an around 5V on the other. Shouldn't the other side be zero? I tested the rest of them and they were anywhere from 0-.8V on the "low" side. The "live" side showed 12V on all when the key was on.

No light in my car works now. I checked fuses inside too. Nothing was missing. I did find that the ground to the transmission was loose. Rarely when driving everything will turn on and flash off... momentarily. Why is this happening now? I have a feeling that I have a short somewhere. Now I have no turn signals or brake lights so I'm really hurting! Any help would be greatly appreicated.

Thanks

Aaron

Grants · Post by **Grants** » December 5th, 2005, 2:35 am

Was that test with the fuse in? If so it must be blown.

Either way - change that fuse. Then check for 12V at the RED wire on the relay. The wire goes directly from that fuse to the relay so you should have 12V there if the wire is ok.

You'll find the 5V isn't really there. As soon as a load is applied it will disappear (problem of using a DMM).

Mazda_Power · Post by **Mazda_Power** » December 5th, 2005, 10:07 am

That was actually with the fuse out. I couldn't get the cover off the back of the fuse block to get at the connections. I swapped that fuse a bunch of times with others (30amps) in the fuse block to no avail. I even took out the HEAD fuse and use an alligator clip to make the connection (since one tower has 12V) and tried flicking the headlights on. They didn't work.

I did check the RED wire when the connection "bridged". I still got 5V. I was going to check the RED wire after I added a direct 12V charge from the battery, but it got cold and I couldn't find a length of wire.

Mazda_Power · Post by **Mazda_Power** » December 5th, 2005, 10:10 am

Thought I'd also mention that I found that the ground from the battery to the transmission was loose. I tightened it down and battery voltage looked much better when running and it seemed to hold a charge better when not running.

Mazda_Power · Post by **Mazda_Power** » December 8th, 2005, 6:08 pm

Bump...

I thought I'd mention that everytime I start the car. The clock with either reset or start at some wierd time. It will never measure time when the car isn't running.

Here is a list of things that flat out do not work:

Turn signals (the noise is made, but no lights come up on dash or on car)

Headlights (High or Low Beam)

Map Lights

Speedometer

Radio

Interior Lights

Rear Hatch Light

Things that DO work include:

Tachometer

Gas Gauge

Temp Gauge

HVAC

Rear Defroster

Wipers

Power Side Mirrors

Grants · Post by **Grants** » December 8th, 2005, 8:17 pm

A lot of that stuff (but not everything) is on the "room" fuse. How about just replacing that first up? Then we can look at the rest if that solves anything....

And replace the "hazard" fuse too....

Mazda_Power · Post by **Mazda_Power** » December 21st, 2005, 5:54 pm

Well, no lights or turn signals work. I replaced the fuse. Any other ideas?