LT Texan

The older they get, it always seems the voltmeter shows a voltage drop when the turn signals come on.

Well, I'm sick of it.

I was thinking, it this a symptom of the main power (IV) relay needing replacement?

Being a 1978, and surely on the original, maybe it is seeing a bit of resistance?

Couldn't hurt?

Thoughts?

(can you tell it is winter - blizzard coming - and I am trying to stay occupied?)

linderpat

mine does too; headlights, turn signals etc. Everything pulls a little, causing a drop in the voltage on the meter.

Alan

Relay IV is for the headlights on a '78 - will not affect anything else - you are better off cleaning grounds and supply connections everywhere I think, including the pod connectors (but carefully now).

Later cars have an Xbus relay in IV - that may be what you are thinking of - but that wouldn't affect this either.

Alan

LT Texan

Alan, the owner's manual refers to the number IV as Main Power Supply (Headlights)

I'm also thinking bad grounds wouldn't cause the voltage drop at the meter, but rather resistance at the relay causing it.

Dan

jpitman2

I had some strange stuff in my pod a while ago - temp gauge went up 1/8" when lights went on, volt gauge flickered in time with turn signals. When I pulled the pod to LED the lights and replace the ign switch I had a ground problem on reassembly - probing the pod connectors with a DVM was enough to loosen the connections to the mylar copper traces. Fix was to over bend the connectors in the connection hood, burnish a little with light abrasive. I think in my model 3 of the connections were grounds in the right hood. All fixed, no more fluctuations or cross feeds.
jp 83 Euro S AT 56k

dr bob

When watching "voltage drop" at the meter relative to the turn signal indicator in the pod, remember that the indicator inside and the bulbs outside are working opposite each other. If the meter dips while the pod indicator is lit, your most likely cause is a weak ground connection from the pod.

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We regularly hear about odd electrical gremlins and wierd symptoms. Please, before you go in just replacing things, complete the annual electrical maintenance tasks detailed in Wally Plumley's excellent guide. Find it on the 928 Specialists website. It includes what should be regular/routine tasks like cleaning the ground points (ALL of them...), battery terminals and battery service, ec. For early cars with ceramic fuses, a little time spent cleaning fuse holders and fuse ends is often rewarded with noticeably better system performance. Do it annually as a PM task, and perhaps some of the odd symptoms will fail to appear in the first place.