Bongo Fury

Having just replaced my alternator, I noticed a kind of clicking on the radio, as if the supply were being very briefly interupted, repeatedly, at irregular intervals. It happens in sequences of about 12 (10-14) clicks, at irregular intervals averaging about one per second or so. It'll go 5 or 20 minutes without doing it at all........and just when I think it's settled down it comes back.
It ought to be the replacement alternator-that would be tidy, wouldn't it? But I remember this happening last year, over a period of weeks, and then stopping.
It sounds as though a relay is chopping in and out, slugging the voltage to the radio.
Anyone heard anything like it or have a clue what it might be?
I hope it isn't whatever it was that killed my last alternator........answers on a postcard, please.......
E.B.

is it a petrol bongo or diesel. if petrol do a search on radio suppressor on wickapedia. or maybe an earth fault on the radio mast itself or radio wiring.

It's a diesel . Have you got a split charge relay? With the last alternator being knackered, the new one will be working harder to top up the LB (if fitted) & perhaps the relay is cycling on & off.

Sorry, it's a 1996 diesel (I've had it for eight years) and I fitted the radio (this is the second one I've fitted and it's been in the van for about three years). It has no split charging system. I'm a fairly competent electrician; I restore motorcycles, designing my own 12 volt conversions and harnesses, and I build and fly electrically powered model aircraft. I understand poor aerial performance and I don't think this is persistent enough to be that. The Bongo power supply system is undoubtedly "dirty" or "noisy" and I'm surprised there isn't more induced noise in the radio, but this sounds like a power supply problem. The real buggabear is the inconsistency/unpredictability of it. It "switches on and off", it doesn't fade in and out. It sounds like a relay, but I'm darned if I can think of a function that would be operating at the times this occurs-it's not indicators or lights of any kind. Maybe the glowplug system? Maybe I should hook into that and see what it's up to?
As I said, it occurred last year and went on for several weeks; then cleared up. I expect it'll do so again, eventually, but it's very irritating and I don't like mysteries-there has to be a reason for it.
E.B.

the alternator you recently replaced and the one you replaced it with are they 90 amp units witth the green coloured band around them,or were/are they the black banded 80amp units.
just wondering about the diodes etc. inside.

Does your radio have a removable face panel perchance....??

Bongolow: Yes, both are 90 amp units.
Jaylee: Indeed it does. You are about to suggest that it might be a bad contact, I surmise. Good thought, I'll check it.

Hi,do you have a clock fitted ( interference),and is the alternator plug clean and secure.

Does this clicking happen only when travelling or stationary.?

The glow plug relay does look like a contender.

Cheers.

Duplicated for some reason

What about eliminating possibilities by connecting it direct to the battery and seeing if the problem goes away. If it does, then consider an alternative feed. Not a fix, but maybe a workaround?

expresso bongo wrote: Jaylee: Indeed it does. You are about to suggest that it might be a bad contact, I surmise. Good thought, I'll check it.

Yep! I had until recently a 12 year oldish JVC head unit.. A few years back it would occasionally cut CD play.. Thinking it may have been a duff cd burn/lint on lens/CD scratch? I paid no mind.. But it never happened again with the same CD on the same spot..
Then i noticed one time the blue screen read out would briefly go blank or occasionally one of the function buttons on the panel might not respond...? Cleaning where it interfaced solved it for me & gave it a bit more grace!

I'm no longer focussing on the radio; I believe the problem there is an indicator of another problem. This morning I checked the charging voltage again (see my thread "alternator failure-no warning light) and it was 11.7, engine idling, low electrical load, 12.7 volts at 2000 rpm. After replacing the alternator yesterday, it was 14.2 volts (i.e. correct) with a fully charged battery. There's something amiss here.
I replaced the battery several months ago-I had a failed start and found low battery voltage; the charging voltage was ok.
Last week, the battery voltage was 13 after the van had stood idle for nearly two weeks.
By the way, I don't have a clock and the "clicking" only happens whilst moving-but I don't sit around with the engine idling much-fuel costs too much for that!
Think I'll go and sit in a darkened room for a few days!
E.B.

Hi
Daft as it may sound, I tracked a similar fault to a speedo on another car...It appeared to be sending some signal or other ...moved the power supplies to the radio, and it improved?...
Cheers
Helen

expresso bongo wrote:I'm no longer focussing on the radio; I believe the problem there is an indicator of another problem. This morning I checked the charging voltage again (see my thread "alternator failure-no warning light) and it was 11.7, engine idling, low electrical load, 12.7 volts at 2000 rpm. After replacing the alternator yesterday, it was 14.2 volts (i.e. correct) with a fully charged battery. There's something amiss here.
I replaced the battery several months ago-I had a failed start and found low battery voltage; the charging voltage was ok.
Last week, the battery voltage was 13 after the van had stood idle for nearly two weeks.
By the way, I don't have a clock and the "clicking" only happens whilst moving-but I don't sit around with the engine idling much-fuel costs too much for that!
Think I'll go and sit in a darkened room for a few days!
E.B.

Might be worth having a look at the mileometer and the trip the next time it happens,they have a habit of sticking (clicking)

Cheers.

Hey, it great to exchange ideas...! Even if they lead to a dead end.

Here is another mad thought.. What about a dodgy switch that stops the mirror motor when fully locked out, activating the motor in the electric mirror housing...? Its on the same loom as the radio...

expresso bongo wrote:It happens in sequences of about 12 (10-14) clicks, at irregular intervals averaging about one per second or so. It'll go 5 or 20 minutes without doing it at all........and just when I think it's settled down it comes back.