head light relay

[js198027]

were can I find a NEW relay im sick of getting everyone elses junk ones.Does anyone make a replacement

[mro]

34364-001 RELAY ASY Yamaha $83.04
Available from bikebandit.com


mro
83 smackers....maybe how they got there name

[js198027]

aftermarket? not oem

[TopCatGr58]

Hey JS,

I found some slightly older threads you had posted while looking for 3Phases tip on fixing his headlight relay problem, but turned out to also be a diode problem, and saw that you had removed your diode from your harness....did you replace the diode?? The relays won't work IF you didn't because they are seeing AC instead of DC on that white latching wire going to the relay.

3Phase also talks about bypassing the relay as well. IIRC it's a 4 prong relay, so I would think you should be able to replace it with a regular relay.
T.C.

[js198027]

Yep I replaced the diode like he said. (now I have a hole package of diodes OH WELL) I have three different relays and none of them work I checked power in and to the white wire and all is good. so I took the relay out of my brothers 550 and the light works great. So I know it is the relay. What do you mean by a regular relay what would i ask for or where would i even go. 80+ bucks is crazy. I did have it bypassed just wanted to do it the right way I guess.

[TopCatGr58]

Found at Autozone:
Part Number: PL-RY1
Weight: 0.15 lbs.
Pricing: $3.99


*********************
found at Radio Shack
12VDC/40A SPST Automotive Relay $6.99
Model: 275-001

Switch on. Switch off.
Use this SPST 12VDC/40A relay as a replacement in your vehicle. Ideal for lighting or accessories.

40A SPST 12VDC automotive relay, simple plug-in
Switch voltage: 14VDC
Relay coil rating: 12VDC
Relay coil power (W, mW): 1.6W
Nominal current at 68°: 133mA, nominal voltage: 12VDC


T.C.

[3Phase]

Getting three bad headlight relays in a row sucks pond water through a thin straw, Josh. I assumed your headlight relay itself was working. My bad. If the relay is not working, changing diodes does not do anything except hone your soldering skills.

TC gave you some most excellent information about replacing the O.E.M. relay with a standard automotive relay. If you want the new relay to stay on when your engine or charging system goes out at night while canyon carving or driving on the freeway, put a latching diode from the Blue/Black wire terminal to the White wire terminal and it will accomplish the same thing as the O.E.M. part.

You can also bypass the relay completely: Anybody bypassed the headlight relay?


There are two separate diodes in your 1980 SG headlight relay circuit. The diode in the wiring harness, attached to the White wire, provides DC to turn on the headlight relay after the engine starts. The other diode is a latching diode that is inside of the headlight relay itself. You can't see it or replace it without opening up the headlight relay.

In the diode replacement thread, Headlight Realy Diode Repair, I had broken the diode myself while moving the wiring harness around so I had to replace it.

In Dim headlight when headlight fuse is removed, the latching diode in the headlight relay shorted internally (overvoltage from a bad regulator/rectifier killed it) and allowed the headlight to come on even when the fuse was pulled out of the 'Head' position in the fuse box.


Regards,

Scott

[John]

So what you're saying here is if the diode in the white wire is good, then a standard 12 v Bosch relay will work?

[randy]

Yes, John,it just won't latch like the original so the light will extinguish if the engine stalls.

[John]

That's good to know. I have a couple of Bosh relays, and although Kat just replaced her headlight relay (Thanks Kurt), the light is very dim, although it was bright when I just had a jumper wire in there. I should be able to open the OEM relay up and clean the contacts, shouldn't I ? Maybe they are corroded.

[3Phase]

A relay is not a relay

I found three part numbers for the headlight relay. I don't know if they're really different or if Yamaha juggled the part numbers just for mucks and change.

The '78 and '79 relays have different numbers and both use the Yellow wire:

'78 E 360-81950-10-00

'79 F 2H7-81950-10-00
'79 SF 2H7-81950-10-00

The '80 and '81 relays have the same number and use the White wire and a diode:

'80 G 3H5-81950-00-00
'80 LG 3H5-81950-00-00
'80 SG 3H5-81950-00-00

'81 H 3H5-81950-00-00
'81 LH 3H5-81950-00-00
'81 LS 3H5-81950-00-00

The unknown model/year XS1100 headlight relay I have in my hand from a bag-o-parts from Pennsylvania has:

(Hitachi logo)

HRI-25
12V710


A Bosch 12V relay should work, BUT:

A jumping tach needle is an easy way to tell if your charging system is not working. A jumping headlight relay, aside from acting as a mildly amusing headlight modulator during the day, can be a whole lot more entertaining at night than a dancing needle.

Use a latching diode to keep the on-at-start feature or wire the relay to come on and stay on with the ignition/handlebar switch.

However you do it, seal everything. The Bosch relays are not waterproof and Yamaha mounted the relay with the wires and connector facing the front of the bike and into the rain.


Regards,

Scott