Fuse 1 & 5

[KMC-DMC]

Hi all,

I'm just finishing some electrical work in my fuse & relay compartment, including installing a new Special T Auto fuse box and i'm checking the operation of all fuses and I can't figure out 1 & 5.

Now I know what the manual says but mine doesn't relate to that at all. E.g removing 5 has no effect on the dash gauges and the fans will stay on ( I bridged the otterstat to check). Neither have I mixed it up with Fuse 1 because both fuses can trigger the RPM relay. And I have to pull both fuses for the fans to stop.

Its all mixed up. I'm totally confused.

Plus Fuse 13 on mine is powering the solenoid valve!

Apologies if my post doesn't make much sense!

Kevin

[David T]

Hi all,

I'm just finishing some electrical work in my fuse & relay compartment, including installing a new Special T Auto fuse box and i'm checking the operation of all fuses and I can't figure out 1 & 5.

Now I know what the manual says but mine doesn't relate to that at all. E.g removing 5 has no effect on the dash gauges and the fans will stay on ( I bridged the otterstat to check). Neither have I mixed it up with Fuse 1 because both fuses can trigger the RPM relay. And I have to pull both fuses for the fans to stop.

Its all mixed up. I'm totally confused.

Plus Fuse 13 on mine is powering the solenoid valve!

Apologies if my post doesn't make much sense!

Kevin

It is possible someone was "mucking about" in the fuseblock and switched some circuits. One way to confirm what is what is to see what the wire colors are to each fuse.

[DMCMW Dave]

It is possible someone was "mucking about" in the fuseblock and switched some circuits. One way to confirm what is what is to see what the wire colors are to each fuse.

Or pull all the fuses out, put them in one at a time and see what wakes up. Do the same thing with your un-attached wires. IIRC the fuse box you installed is a different layout than the original so some of the fuses do end up in different locations, i.e. the original diagram won't work any more.

[KMC-DMC]

Thanks for the input.
I've been using the colour wiring diagram to check all the wires - unfortunately Fuse 1 & 5 have the same colours!
In the past a PO had messed about with the wiring...

[DMC5180]

Fuse 1 should supply 12V via a Green wire to the RPM RELAY, IDLE ECU, IGNITION CONTROL UNIT and VACUUM SOLENOID

Fuse 5 should supply 12V Via a Green wire to the INSTRUMENT CLUSTER (gauges and warning lights) and supplies the 12V feed to the OTTERSTAT.

[Bitsyncmaster]

This is why I recommend doing one wire at a time when replacing the fuse block. I kept my original fuse block which I cut each wire off and can verify the fuse block has fuse 1, 3, 4, 5, 13 each to have one green wire. Fuse 1 and 3 have a larger gauge green wire than the other three greens.

[Bitsyncmaster]

Here is a photo of the back side of the OEM fuse-block.

[KMC-DMC]

thank you all for your responses.

I found what the problem is.....the PO.

They cut the entire loom and have incorrectly crimped the wires back together. I've not idea why they did it.

[David T]

thank you all for your responses.

I found what the problem is.....the PO.

They cut the entire loom and have incorrectly crimped the wires back together. I've not idea why they did it.

See post #2. We call that the DPO (Dreaded Previous Owner). From experience, most of the work required is to undo, or redo correctly, previous work by DPO's and/or their mechanics. Once you find something like this you now have to suspect the entire electrical system in the car. The car probably had a melt-down in the fuse block and this was the resulting fix. The biggest problem with switching circuit is now, since you don't know what is for what, you will stick the wrong size fuse in. Could be dangerous.

[mluder]

Here is a photo of the back side of the OEM fuse-block.


OK... This is interesting, Dave. I noticed there's noting coming out of 18. I just discovered this on accident on my car tonight. Isn't that supposed to be the stop lights according to the workshop manual and the wiring diagram?

Cheers
Steven

[Bitsyncmaster]

OK... This is interesting, Dave. I noticed there's noting coming out of 18. I just discovered this on accident on my car tonight. Isn't that supposed to be the stop lights according to the workshop manual and the wiring diagram?

Cheers
Steven

My car and many others have the brake light fuse in the harness up near the brake pedal. Don't know when it was changed to the fuse block #18.

[KMC-DMC]

I noticed the same while repairing the mess that was my wiring loom.
There was an inline fuse that took power from a constant live feed under the steering column and connected to the brake light switch.
I removed it and connected to the switch what looked to be the original feed; which only works when main fuse relay is engaged.

[DMC81]

My car and many others have the brake light fuse in the harness up near the brake pedal. Don't know when it was changed to the fuse block #18.

I did my fuse box last weekend and my car is the same way, fuse 18 is empty. I was glad it worked out that way in case I want to add something down the road. I did it like you had said Dave, one fuse at a time and for the most part it went well.