Issues with Classic Retrofit fuse block

[rangrbob]

I recently purchased a Classic Retrofit fuse block upgrade for my 71. After installing it and confirming all the wires were attached to the same positions they came off the old fuse block, I reconnected the batteries and tried all the switches. Most everything worked the way they should, however, there were a few issues.

The low beams would flash when hazard warning lights were activated.

When the right turn signal was initiated, the headlights and fog lights would flash as well.

When the high beams were on the fog lights and right rear brake light would come on as well.

The high beams would stay on even if I pulled their fuses.

All grounds where checked and were good, and I double checked the wiring with photos and the wiring diagram.

I removed it and re-installed the old block and everything works the way they should. Since electrical parts are not returnable, I’m hoping the community may be able to help. I’d hate to have wasted $400.00.


Any thoughts or ideas where to look would be appreciated.

Thanks

[Ian Comerford]

I’m sure Jonny will be interested in this problem as his customer care is very good. Have you been in touch with him?
Your problem may be similar to the one I had because it turned out that my wiring wasn’t standard or in standard positions and the built in bridges in one case didn’t function because of that. Simply reverting the fuel pump wiring to where it should have been cured the problem. It may be worth checking your car’s wiring against a wiring diagram.

[manbridge 74]

Probably a case requiring further “fettling” in order to say it “works a treat.”

This thread does remind me to spin the fuses in my 48 year old panel though...

[Jonny H]

Originally Posted by rangrbob

I recently purchased a Classic Retrofit fuse block upgrade for my 71. After installing it and confirming all the wires were attached to the same positions they came off the old fuse block, I reconnected the batteries and tried all the switches. Most everything worked the way they should, however, there were a few issues.

The low beams would flash when hazard warning lights were activated.

When the right turn signal was initiated, the headlights and fog lights would flash as well.

When the high beams were on the fog lights and right rear brake light would come on as well.

The high beams would stay on even if I pulled their fuses.

All grounds where checked and were good, and I double checked the wiring with photos and the wiring diagram.

I removed it and re-installed the old block and everything works the way they should. Since electrical parts are not returnable, I’m hoping the community may be able to help. I’d hate to have wasted $400.00.


Any thoughts or ideas where to look would be appreciated.

Thanks

Firstly, I can categorically say there are no design issues with any fuse panels we sell. The design has been the same for a few years now and well over 1000 units in service covering all model years. Manufacturing issues are very rare and would not cause the type of issues described.

There is some re assignment of fuses required for installation in a '69 car as the busbars are different. All other long hood models have the same bus bar arrangement.

Firstly, check that the busbars on the back of the original blocks match the bussed terminals on our panel. These are indicated by white bars on the front of our panel between the terminals. If that is not ok, then your original fuse blocks are likely not correct and that will be at least part of your problem. As said previously, we know the '69 busbars are different but all others are the same.

I know you have said that you doubled checked but the most likely explanation is still a mis wire. It is very easy to forget to skip a gap on the output side of the fuse. Did you take on board that the relay marked 'H' is extra and not to be included in the like for like swap over?

Observations:

1) all your issue are lighting based. Lighting is on the lower 10 fuses

2) head lights flashing with turn signals would be consistent with having the turn signal wire offset by one terminal as they are side by side.

3) if all the remaining iighting wires were out of place by one terminal you would get a confused lighting arrangement for sure.

4) I can't explain the rear brake light coming on since these lights are not fused and have no connection at the fuse box. If it was the parking light then this might be back fed from the licence plate lamp which is second from bottom.

5) If headlamps stay on then that is a back feed of the relay. This can be caused if the output side of lower fuses labelled 3 and 4 are connected together. (white/yellow, yellow) They should not be.

There's a run down of the fuses on this thread:

911 fuse panel question

[Hx911]

I found it is really important to check and double check, especially the connected terminals.
When I installed the rear Fusepanel from Classic Retrofit, i felt it was totally wrong. Removed it and fitted the old fuses.
Then I investigated and found in that instance there are 2 different rear fuse panels used by the factory, one of them is 'upside down'. So iI found i had to swap some wires, and all is fine.

At the front I still struggle to find what the previous owner did to the headlight wiring, I suspect a defect column switch plus some attempt to compensate for that in the wiring. Only affects the headlights, so I just dont drive in the dark at present ;]

[Jonny H]

^ Exactly this. These cars have so many interchangeable parts that will 'fit' but don't necessarily work as intended.

Example. Even with the original parts, if you fit a Carrera 3.2 rear fuse block to a long hood, you cannot switch the engine off!

[FrontGarage911]

I recently retrofitted my coupe a few weeks ago. Being as careful as possible numbering and labeling each wire I still managed to have a few danglers. Thank goodness I took several photos so I was able to reference back countless times to see where the wire mated up to.

[rangrbob]

Thank you Johnny and the rest of you for the replies and links. I’m going to try again and see if I can track down what I may have missed.

[rangrbob]

Johnny,

From all of the wiring diagrams I've researched for my car, and comparing the bused fuses on the stock fuse block, it appears fuses 3 and 4 on the lower eight should be bused together similar to fuses 1 and 2. They are not on the fuse block I purchased from our host. Are there different versions of your panels for early cars, or do I need to bridge those two fuses?





Thanks.

Karl

[Jonny H]

^ 3 & 4 are not connected topside because we have an option not to use the relay by connecting to 4. Why? Because some euro cars use electronics to run the dip beam at a lower output level for parking lights. That system uses 4 and cannot use a relay.

You should only connect light feeds at 1 and 3, Do not link anything, top or bottom.

[Classic 911]

Following


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[ian c2]

[ChrisHoover]

I know a lot of folks think electrical systems are voodoo but a systematic approach will easily resolve this problem. Get some alligator clip jumpers. remove each conductor you think goes to a light. Connect using the jumper to the battery. What lights up? Mark the cable. Go through all of the suspect circuits and ID them. Now connect them to the right fuse.

In electrician terms one side of the fuse is called line and the other load. The load side goes to the lamp, the line side goes to the switch. The switch could be the actual switch on the dash or the a relay contact. Leave the line side be. If you remove the line side you’ll have more problems. Once you get the loads in the right spot and it is verified by using the switch, mark the line side too.

I found the schematic drawing 90% accurate when rewiring my car. The wire colors were mostly correct. The complication with the wiring on my car is Porsche uses the fuse block as a splice point. There are conductors that are not fused but are cross connected using the line side of the fuse block. It makes it a bit difficult to grok at first. If the harness is unmolested the conductor colors are a big help in ID the circuit

[Jonny H]

Originally Posted by ChrisHoover

I know a lot of folks think electrical systems are voodoo but a systematic approach will easily resolve this problem. Get some alligator clip jumpers. remove each conductor you think goes to a light. Connect using the jumper to the battery. What lights up? Mark the cable. Go through all of the suspect circuits and ID them. Now connect them to the right fuse.

You can actually use our fuse panel to do this. If you take the fuses out, each circuit (when active) will light the red LED. So for example with fuses out, switch on the light switch and see which LED is lit. You can then cross reference this to the wiring diagram for your car.

[Joe Bob]

The only issue I had was two fuses being lower rated than required.

BTW-spinning the old style bulletin fuses is a good idea but do a physical inspection or replace them if they’ve been in service many years. I lived right on the coast and apparently spun them a bit much and wore the contact on the fuse off. Caused me significant amount of angst before I figured out why my DME was intermittently futzing out.

[digitaldgp]

Following....

[r-mm]

I bought a Dymo Rhino 4200 heat shrink label printer when I took on the manufacture of a 964 Headlight Relay kit... immensely satisfying and not hugely expensive. Keeps things in order when working with lotsa wires.

[7783911]

My Classic went in without any hitch, being careful to mark and match wire positions (77 Targa)

My only issue now is the fuse cover really doesnt fit to the metal tanks well, the new fuses protrude a bit more...I hvnt figured out a way to address this yet and dint get a response to my inquiry to Classic if they had seen this issue before and had ideas....

[Hx911]

I have the same issue - the fuses seem to be just that bit to high in their sockets, for the cover to fit properly. In my case - the previous owner has fitted some velcro to hold the fuse cover in place, so now with the Classic Retrofit fuse panel fitted I just do not clip the cover in at the bottom.
Maybe there are some fuses that are not as height, or it needs a change in design in the future to accept the smaller size blade fuses. not sure it this is possible though

[pocketscience]

I started looking at installing my CR fuse panel.. but my car is a LHD -> RHD conversion and whoever did the job (back in the mid-70's) was pretty liberal when it came to the fuse panel. It bares little resemblance to the archetype fuse panel in the wiring diagram. This is going to be fun..