Full Beam Won't Latch?

[Guest A.B]

Hi guys,

 

I bought my hood a few year back and it's been sat in the garage as I went back to uni.

 

Is it a relay that latches the full beam to stay on? I have dipped beam, flash full beam ( pulling stalk back ) but I get nothing when I push the stick forward to latch a constant full beam. When I push forward i don't get any battery voltage drop like when I pull back for flash.

 

I have a week off and hoping to get a few bits done.

 

Any advice would be greatly appreciated.

Edited May 28, 2016 by A.B

[fry61]

Probably a duff switch contact -- it is possible to clean the switch but be very careful -- lots of small pieces & springs await!! Are your dip/head lights through relays? If not the current drawn could be the cause of the switch failure.

[Guest A.B]

I have purchased a second switch same part numbers and the fault still persists. I have a ford flasher relay, two silver relays and three black relays present in the fuse box.

[Guest A.B]

Switch number 87BG 13B 302AA

 

Obviously no guarantee the second switch isn't dead too!

 

Any chance I can test for continuity between the pins?

[Guest A.B]

Am I correct in thinking its between the first pin and switching across 55 & 56 for flash and full beam as that's what I'm getting continuity across when switching both switches?

[Longboarder]

It's the left column switch that contains the dipswitch and the flash. Right column switch just does off/side/power to dipswitch. So dip beam working confirms the right column switch is working OK.

 

For the left column switch there are a number of ways to wire this up. Ford used a switched earth via a pair of relays (ignoring the complicated extra relays for dim dip) rather than switched power but some owners changed this to switched power. Most however will use two relays, one for dip and one for main.

In either case 56 connects to either 56A or 56B within the switch (depending if its on main or dip) and then 56A and 56B go off the one of the switching terminals (either 85 or 86) on the dip and main relays.

 

You can check which system (pos or neg switching) you have by checking the polarity (zero or 12volts) with a multimeter on the wire that connects to terminal 15 on the left column switch.

 

Thinking about it dip and flash working confirms both external relays so the fault must be the switch. Are you sure that you have dip, flash but no main beam? Could it be Main, flash but no dip??? That would point to either a switch or relay fault. Either way check continuity in the switch, 56 to 56A, 56 to 56B and for flash, 15 to 56A. If all OK, identify the two relays and swap to see if the problem moves.

Then report back.

 

Nigel

Edited May 28, 2016 by Longboarder

[Guest A.B]

I think I have fried a relay.

 

Anyone have a clue where I'd get some of these from?

 

[Guest A.B]

Are those the relays that dipped and full beam go through or the black ones?

[Guest A.B]

I have just remembered I started this topic last year here;

 

http://www.rhocar.org/index.php?showtopic=41748&page=2

 

It was well I was testing, i believe I blew the relay

[Guest A.B]

Could anyone just check that there are generally 5 relays? Two silver ones, a large black flasher unit and two black relays which are the same PIN numbers and layout

[Longboarder]

I don't think that can be confirmed. Each car is built by an individual and will have differences. I have nine relays and 26 fuses. All you can do is identify what you have.

Remove a single relay, turn ignition on and try all the electrics and see what has stopped working. That should help identify the purpose of each relay. I hope that will also identify a relay which seems to make no difference if it's in or out. Also examine the terminal numbers of the pins and the number of pins. That can give clues as to what they do also. The commonest relay you will find has four pins numbered 85, 86, 87 and 30. Those are simple on/off relays and can be replaced from the shelves in Halfords.

 

Nigel

[Guest A.B]

Halfords don't seem to supply a 40amp version of what I'm after.

 

What's in the car at present is a 40amp version of this:

 

http://www.halfords.com/webapp/wcs/stores/servlet/ProductMobileDisplay?catalogId=10151&langId=-1&categoryId=310504&productId=753485&storeId=10001

 

They do a 40amp but it doesn't switch between two positions of 87

[Guest 2b cruising]

30 amp will be pleanty for headlamps.

[Guest A.B]

The problem is I don't know what's going through each relay. I've already had a load of smoke coming out of a 40amp. Tested and seemed the relay switch had fused. Hopefully it hasn't gone any further as it didn't blow any blade fuses

[Longboarder]

Accuracy is all. Read the base terminal numbers. This style of five blade relay, commonly used for lighting comes in three configurations. 30,85,86,87, 87. 30,85,86,87,87a. 30,85,86,87,87b. Get the correct one.

30amp is easily sufficient.

If the currently fitted relay is a 5 blade changeover with terminals 87 and 87a then your builder used a single relay to switch between dip and main.

 

Did you confirm weather you had dip and flash or main and flash? Only the latter would be sorted by a new relay.

 

Nigel