Thanks Mark.

I see your point. The only way I can find out if the added "coil"
relay is at fault, is to leave out the fridge relay.

That would be the right way to do it. --- :^)

I like the diode idea. I'll check out the later model year diagrams. I
have an '85 cluster in the basement I can look at too.

One of these days I'll get better at this electrical stuff.

Wait a minute. I am!

 --- ;^)

Neil.

On Sat, Aug 9, 2008 at 4:07 PM, mdrillock <mdrillock@cox.net> wrote:
> Neil, if the fridge relay you just added is using the blue wire it might now
> mask the problem of engine run-on since it would be an additional load on
> the circuit like the brake bulb was. The run-on problem may disappear or
> occur less frequently now but it is not solved by this either way.
>
> Looking at the various years diagrams in the Bentley I see they added a
> diode to the blue wire circuit of the instrument cluster beginning in 1985.
> They would have done this to prevent the type of problem you are having. If
> the existing black wire won't carry the load in place of the added relay you
> could just add the diode and keep the relay. The diode blocks the alternator
> D+ from providing reverse current flow to the black wire circuit of the
> ignition switch after the switch is off.
>
> I always upgrade my earlier vans to tachometer clusters or I would have
> likely run into this problem before myself.
>
> Mark
>
> neil N wrote:

>> I just added a fridge relay downstream of the aux battery relay. It
>> would have been there in the stock configuration and if I keep my
>> Dometic 182B (dang thing still goes out randomly!) I would hook up the
>> 12V eventually. Regardless...... I'm sure you're right. The added
>> relay is likely staying closed. This makes the most sense.
>>
>> The detail about the added relay was something I'm not sure I posted
>> when originally asking this question.
>>

>> I too had thought to run a heavier gauge wire from the ignition switch
>> so the wiring remained stock, but it would be good practice to learn
>> how to measure current flow and see (thank you internet) if the
>> existing wire is sufficient.