Headlight relay oddities

[Viper GTS]

I just finished (well, I thought I'd finished) installing a headlight relay system for my 1993 Jeep Grand Cherokee Limited.

Everything worked the first time I turned it on, the headlights both work and are nice & bright. However, after using them something seems off.

When you first turn the lights on what appears to be the low beams come on. This is normal and expected. When you turn the high beams on though it seems they cannot be turned off. Further switching of the high beams appears to turn the low beams on/off. The only way to get it back to just the low beams is to turn the lights off completely, and then back on.

I'm using parts from danielsternlighting, with one stock socket driving the high beam relay and one stock socket driving the low beam relay. I didn't cut the stock harness, the wiring harness I made has 9004 sockets to interface with the factory wiring. I have replaced the factory lamp assemblies with glass fronted ones that take H4 bulbs.

Wiring Diagram (from DanielSternLighting)

The questions:

1) Is it normal to have both filaments of an H4 bulb on at the same time, or should the low beams shut off when the highs are on?
2) I see diagrams online of both relays being driven by the same factory socket, is it possible that my split setup is causing my problems? I can't really see how it would matter, but maybe it does.
3) Is it possible that I simply have the high/low relay inputs reversed? It doesn't seem likely since the lows come on by themselves when the headlights are first turned on.

I'm beginning to wish I had ordered a pre-made harness but this really shouldn't be that difficult. What the heck am I missing?

Viper GTS

 

[1prophet]

The relay that is supposed to be off is it receiving power on the coil side causing it to latch on until you kill power to both high and low beams?

 

[Viper GTS]

Originally posted by: 1prophet
The relay that is supposed to be off is it receiving power on the coil side causing it to latch on until you kill power to both high and low beams?

I'm assuming something like that is happening, but I don't know why.

Viper GTS

 

[1prophet]

Originally posted by: Viper GTS

Originally posted by: 1prophet
The relay that is supposed to be off is it receiving power on the coil side causing it to latch on until you kill power to both high and low beams?

I'm assuming something like that is happening, but I don't know why.

Viper GTS

Use a test light and follow the diagram to see where the voltage to terminal 86 on the relays is coming from when the light switch is in high or low mode.

 

[alkemyst]

Originally posted by: 1prophet

Originally posted by: Viper GTS

Originally posted by: 1prophet
The relay that is supposed to be off is it receiving power on the coil side causing it to latch on until you kill power to both high and low beams?

I'm assuming something like that is happening, but I don't know why.

Viper GTS

Use a test light and follow the diagram to see where the voltage to terminal 86 on the relays is coming from when the light switch is in high or low mode.

May need a diode, can't tell without knowing more about the system it's attached to.

 

[Zenmervolt]

Originally posted by: Viper GTS
The questions:

1) Is it normal to have both filaments of an H4 bulb on at the same time, or should the low beams shut off when the highs are on?
2) I see diagrams online of both relays being driven by the same factory socket, is it possible that my split setup is causing my problems? I can't really see how it would matter, but maybe it does.
3) Is it possible that I simply have the high/low relay inputs reversed? It doesn't seem likely since the lows come on by themselves when the headlights are first turned on.

I'm beginning to wish I had ordered a pre-made harness but this really shouldn't be that difficult. What the heck am I missing?

Viper GTS

1) When the "flash to pass" feature is used, both the low and high filaments should be on. When the high beams are on steadily, the low beam filament should not be on.
2) Can you post a wiring diagram of the system as you've installed it? I can't quite visualize what you've described so I want to be sure I'm understanding.
3) No, they aren't simply reversed. If they were, the high beams would come on with the regular switch.

Thinking about it a little more, it does sound like the problem could be the fact that you're driving it off of two sockets, but I can't be sure.

ZV

 

[Viper GTS]

I used both sockets in an effort to avoid constant "you have a headlight out" messages.

I'll draw up a diagram and post it.

Viper GTS

 

[Viper GTS]

OK, here's what I have now:

http://pics.bbzzdd.com/users/ViperGTS/jeep_relays.png

Viper GTS

 

[1prophet]

Originally posted by: Viper GTS
OK, here's what I have now:

http://pics.bbzzdd.com/users/ViperGTS/jeep_relays.png

Viper GTS

If you have 5 connections on the relay the normally closed terminal shouldn't be connected if it is, it might be labeled as 87a . The ground that comes off the original headlight sockets, try putting that to a known good ground.

 

[Viper GTS]

These are dual output relays, they're both 87 - There is no 87a.

Viper GTS

 

[1prophet]

Originally posted by: Viper GTS
These are dual output relays, they're both 87 - There is no 87a.

Viper GTS

Assuming everything is wired correctly.

Take a test light and check both relays for power on terminal 87 when the lights are on high or low. Then check their corresponding 86 terminal for input voltage.

If the relay in question has power but actually shouldn't on terminal 86 disconnect power to terminal 86 and see if terminal 87 loses power and the lights go off.

If it does then you have stray power on terminal 86 turning the relay on, if not then the problem lies elsewhere.

Make sure there is no stray power backfeeding into the ground side of the relays also.