Fuse Box Replacement

[jag09]

I had been trying to figure out this lighting issue I had since I bought the car, finally threw in my hat and took it to a shop. Got back bad news. They are recommending that I replace the whole Fuse Box as the Low beam check relay is bad. Has anyone replaced a fuse box in a car? I found one used on classic daily but im not sure if I should chance it with a used fuse box or just let the shop do the install and fix. Below is the write up from that part of the diagnosis:

- Verify Client Concern: Verify - This appears to be true, but the low beam bulbs on this car are duel filament. One filament is for
low beams, and a 2nd is used in conjunction with the inner bulbs for the high beams. When the high beam switch is activated, only
the proper high-beam filament is being energized. So the low beam circuit is non-functional.
- Check fuses 14 & 15, which are for left and right low beams - fuses are good
- Check for voltage at fuses with key on and headlights turned on - no voltage
- According to wiring diagram, fuses 14 and 15 get voltage from low-beam relay THROUGH the low-beam "check relay", which is
integrated into fuse box circuit board.
- Checked for source voltage at pin 30 of low beam relay - 12v.
- Applied jumper wire to bypass low beam relay (if lights come on, then relay is bad, or something pre-relay, like the switch) -
lights did not come one.
- Verified that 12v was reaching pin 87 - yes.
- Applied voltage to fuses 14 & 15 and low beams come on - This verifies that the wires from the fuse box to the lights is good.
- With relay jumped, checked voltage at fuse 14 and 15 - still no voltage - The only thing between low-beam relay and fuses 14
and 15 is "low beam check relay", which is integrated into fuse box.
* Diagnostic Results: Low beam check relay is bad, requiring replacement of fuse box

[jeffnhiscars]

Not sure if you're the same person who asked this in bimerforums but same answer...it's a huge pain to swap the fuse box and there are no relays built in to it.

[jag09]

I am, I just replied back to that forum as it got more replies

[Seawolf]

The low beam check relay is mounted (soldered) on to the fuse box printed circuit. The relay is powered by the low beam relay (K4) which in turn powers the left & right low beam fuses (13 & 14) - if the check relay fails then neither fuse will get power.

The fuse panel part # is 61131370763 and goes for around $180.

You can bypass the check relay with a pair of jumper wires directly from the low beam relay power output to the fuses though you will need to pull the fuse panel to get in to the circuit for soldering.

If you were really lucky you might discover a bad solder joint on the check relay. Another alternative is to source a new replacement relay and get busy with your soldering iron, the relay isn't cased and I have no idea where you would source one from, but it's just a surface mount relay after all.

[jeffnhiscars]

a check relay shouldn't effect the operation of the lights though

[Seawolf]

I agree it shouldn't but it does.

The K4 dipped headlamp relay power output connects to the check relay, not the fuses.

The check relay provides power to both left and right fuses from power output legs A & C, if the check relay fails then neither fuse will get power. Though it might also be worth checking that G200 and C114 pin 3 are providing a good ground.

The BMW electrical troubleshooting manuals don't provide the circuit diagram for the fuse panel printed circuit but the check relay is sort of shown on the Active Check Control schematic:

http://wedophones.com/Manuals/BMW/1989%20BMW%20325i%20-%20325is%20Electrical%20Troubleshooting%20Manual.pdf

Section 6216-0 (page 48). You can see the the headlamp fuse feeds from the check relay. If you jump the K4 power output to the power input of fuses 13 & 14 and the dipped beams come on then the problem is the check relay or a bad circuit connection.

I'm sure this is repairable for a lot less than the cost of a new fuse panel provided the rest of it is okay, sourcing the relay could be fun but the panel is still available so someone out there makes that relay.

Anyone got a dud fuse panel kicking around out there ?

Edit: Check Relay is also shown on 0670-4 Power Distribution (Page 16).

[jag09]

I took out all of the fuses and relays to try and access the board. Heard there was different color boards so got to mine and saw that it was red just for clarification. Going to go ahead an order a new(used) fuse box at this point because if I am going to have to pop out each wire to access the board, I might as well go ahead and replace it.


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[Seawolf]

Okay, sounds like a plan.

Want to send me the old board ? If I can ID and obtain the relay I'll write up the repair replacement or bypass, might be useful for board members experiencing the same problem in future.

PM me your Paypal and I'll send you the shipping.

[jag09]

Okay, sounds like a plan.



Want to send me the old board ? If I can ID and obtain the relay I'll write up the repair replacement or bypass, might be useful for board members experiencing the same problem in future.



PM me your Paypal and I'll send you the shipping.

Before I say yes to sending you off my board, are all e30 boards in the fuse box the same? Also at my current employer we work with a lot of electronic component companies to source stuff so depending on how compatible the circuit boards I might have a guy at work find the relay and fix it. Pm me on how much you would charge and ect to fix it!


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[jag09]

Finally got my new to me replacement fuse box in after ups delaying the delivery a couple of days. Still haven't found a good way to pop the terminals out yet


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