1993 4G central fuse box

[HG65]

Hi,

I'm looking for a central fuse box for my 1993 4G 2L 5 speed manual Prelude. There is a problem with the windscreen wipers not coming on in the intermittent mode or after using the screen washer sprays. Parts and/or advice more than welcome!

Many thanks,

H.

[Drax]

could be the actual stalk at fault, difficult to determine. i would guess this is an electrical short somewhere more than a fusebox issue. i have a spare under bonnet fuse box if required though.

where are you located? as an experienced 4/5g owner may be nearby to help

[Scott560]

On the 5g, on the back of the fusebox is the multiplex control unit, which controls most of the non-simple functions. Inside the car, this is the bit that the large loom plugs into at the bottom of the fusebox.

The post sounds like the switch is working in the most - but seems to happen 'after' something has happened. Sounds like an MCU failure especially if its been looked into already. Perhaps it was fried somehow (old posts from OP show car was attempted theft!)

There is a section in the 5G manual about how to test the MCU , you can get it into a programming mode, and then work through every input and output 1 at a time , bypassing the switches to test each function I believe. I have no idea if the 4G and 5G MCU's are similar or if the process would be helpful.

If the switch and wires appear all OK (test with multimeter), then MCU/fusebox is a good shout.

[vanzep]

Pics of the footwell interior fuse box with mcu on the back
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Pics of the under bonnet fuse box with eld (electrical load detector)
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Pics of big square fuses found in under bonnet fuse box

Parts and manual are here if you need them. Hope this helps

[HG65]

Hi,

Thanks for all your replies.

The mechanic who worked on my car to get it going, great though he is, admitted that he was not so expert on the electronics side of things, so I think it might be easier to get a replacement MCU/fusebox which he can then fit, rather than finding someone else to test out the system as Scott560 described.

Vanzep, would be interested in contacting you again regarding the parts you have - you've been more than helpful in the past.

Thanks again,

H.

[wurlycorner]

could be the actual stalk at fault, difficult to determine.

The only part of the circuit that links wiper operation with the washer, is the ICM (per circuit diagram in 23-340 of the service manual and the fault finding chart - which is actually helpful in this instance - on 23-342).

Assuming that the washer pump itself is working ok, then the things to check to confirm this 100% are;
1. Do your intermittent wipers work normally when turned on (if not, then your intermittent wiper relay is probably faulty)
2. When you pull the wash switch, is there 12v on terminal B11 in the under-dash fuse box (if not, then there is a break in the wire somewhere between the washer switch and the under-dash fuse box)

Note that if you confirm the ICM is faulty and go to swap the fuse box, you need to match the fuse box part numbers, because there are differences in these fuse boxes across 4g's (the ICM varies dependent on equipment level etc).

[Hagland-BB4]

I have the under bonnet fuse box for sale if you need it

[vanzep]

H said:
Vanzep, would be interested in contacting you again regarding the parts you have - you've been more than helpful in the past.

Thanks again,

H.

My Reply:

No worries i have sent you a pm with contact details - give me call anytime tomorrow or reply on here

[HG65]

Thanks yet again to Vanzep for parts and to other members for their helpful advice.

H

[vanzep]

no worries H - hope you get it sorted - do let us all know how it goes
would be good to see the lude - i might have seen it once before 3 or 4 years ago on ferry road in Edinburgh - silver and looked in very good condition