Surprising Electrical Gremlin, headlight dimmer kills engine... Options

[kdfoust]

I'm still driving around my 3.2 conversion in shakedown mode. After the first drive at night I thought I noticed that when I flicked on the high beams the engine cut-out for an instant. I spent a little time debugging the problem last Sunday and found that 30% of the time when I flicked the high/low beam switch on the column the engine would cut out for an instant. It didn't matter whether the switch was going from high to low or vice versa. 30% of the time the engine would cut-out. I pulled the hi/lo beam relay and disassembled it, touched up the contacts with a die makers file, cleaned it with electrical contact cleaner, blew it out and re-assembled it. When I re-tested the relay by flicking the headlight between hi/lo beam the engine now cut-out 100% of the time! I thought that was pretty interesting (IMG:http://www.914world.com/bbs2/html/emoticons/huh.gif) and went in and ordered a new relay from Pelican. Tonight I put the new relay in and the problem is completely gone as expected. I can't wait to find out if that was also the cause of a day-time "miss" that's been kinda coming and going...
(IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

These old cars never cease to entertain me with bizzare symptoms and surprising causes. (IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif)

Later,
Kevin

The old relay...

[Chris Pincetich]

I just got a new relay too - and wanted to know what you did about the connections. The old relay has F and 56 a, the new realy has 56a and 56b, then a 5th plug off to the side of the main four.

I just hooked up the main four in the same pattern as the old relay and now have the extra plu on the new relay bare. So for mine, I put the old F onto 56a. Is this what you did too?

I have several issues:
1) only high beams worked before with old relay, now I toggle back and forth with new relay and it is only low beams
2) fog lights didn't work (new Pilots) before, after new relay I blew the fuse and they still don't work

Damn gremlins! (IMG:http://www.914world.com/bbs2/html/emoticons/ar15.gif)
(IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif)

[kdfoust]

I made a jumper which connects term 30 with term 56. Connect the car wiring to the new relay in the same positions as it was on the old relay. The jumper allows the new relay to be functionally equivalent to the original.

If you change to this wiring hookup I bet it'll clean up your fog and high beam issues.

It's all in good fun... (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

Later,
Kevin

[Chris Pincetich]

Thanks a million (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)

If you feel like expanding on this - how in did you figure this out, to add the jumper?? My relay did not come with any wiring diagram...the old one actually has it printed on the side.

Looking forward to getting home tonight and trying this out!
(IMG:http://www.914world.com/bbs2/html/emoticons/cool.gif)

[kdfoust]

Without the wiring diagram it would be a little tougher to figure out how things go together. (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

I had forgot the F was missing on the new relay. On the new relay F=56a, or that's how I did it too.

So I wound up with something like this:
(old relay->new relay)
F->56a (hi beam)
56a->56b (low beam)
S->S (ignition)
56->56&30 (light switch)

Here's the diagram on the relay I got.

This post has been edited by kdfoust: Jan 11 2006, 09:24 PM

[kdfoust]

Here's the little schematic of the original relay that I was working with when I was troubleshooting that shows what the various connections do.

[DJsRepS]

I understood the hi low relay was a latching relay. The switch on the colum only gives the relay a momentary signal that latches it in its other position. A regular relay as the round headlight relays only hold contacts as long as the coil is energizied.

[watsonrx13]

Here's a shot of the replacement wiring...