PV444 dome light blues

[blueosprey90]

When you accidentally buy an '57 Volvo, 6 volt car, it is not without its problems.

The current issue (one of many) is that I cannot seem to fix the dome light. As delivered, the dome light bulb was burned out and the two-position switch (which seems to work off of a ball bearing) was broken. I jury rigged a repair to the switch with a ball bearing (4mm, I think). I replaced with a 6V 10W festoon bulb.

The fixture itself looks like an aftermarket part as it has no markings whatsoever.

I have 6 volts (plus or minus) across from the two hot wires in the roof to ground. I have continuity from the power side of the switch to the ground side of the switch through the bulb. If I use some pigtail wires on the fixture and touch the + and - terminals of the battery, the bulb glows brightly.

But, I cannot get the fixture to work if I connect it up at the interior ceiling. I'm pretty sure my ground is good since I used a Dremmel tool to scrape off some of the paint under the headliner.

I've made many, many attempts to hook it up without success. Any advice appreciated.

[Ron Kwas]

bo90;

Welcome to this forum.

"Accidentally" huh?

Courtesy Light (Roof Light) is supplied with power from Fuseblock and gets chassis connection from either switch at fixture OR wire running of to Door Contact as shown in this wiring diagram excerpt:

Source: http://www.sw-em.com/544_6Vwiring.jpg

Good Hunting!

[arcturus]

The 1.5 black from roof light re appears behind the driver side, side kick panel and is grounded by the door light switch. Remove this panel and check connections. I had a similar problem with mine.

[blueosprey90]

"Accidentally" huh?

It was a slow day at work and I was on the Bring A Trailer auction site.



Thanks for the replies.

It snowed last night, but I think I'll push the car out of the garage (better light) and check again. Although I seem to have voltage at the switch with the switch disconnected, I must have a voltage drop somewhere so not enough voltage to light the light.

[Volvorama]

I had a 1955 PV444 and as I recall the interior light was the same as an Amazon inside but used a slightly different cover.

[blueosprey90]

It wasn't easy, but I got the light to work.

The problem seemed to exist at the fuse box. Fortunately, a prior owner had sprayed the engine bay with black primer resulting in all of the wires being black - which just adds to the fun.

And I think the wiring has been modified a bit, so the wiring diagram was only partially helpful.

In the end, I ran a jumper wire from the #5 to the #4 fuse terminal. With power at the fuse, the dome light worked just fine. There is a second wire leading from that fuse terminal, but I never did figure what it went to.

I did isolate some of the of the other wires. I did manage to get the heater fan to work - but it seems pretty lame. If there is a separate fan for the back seat, I didn't find it.

The headlights have a problem in that one of the parking lights goes off when the headlights are on. But the bigger problem there is that they need to be aimed much lower than where they are aimed now.

I think I have a bearing starting to go. Not sure if it might be the water pump or the generator. Noticeable squeal on start-up when the car is cold, but it does quiet down once warmed up.

[arcturus]

4 to park light I believe. Squeal could be fan belt. heater in the back? are you kidding!

[blueosprey90]

Doesn't sound like a fan belt squeal. Seems more metallic.

I have to say that the overall impression is that engine is much noisier than I expected. I run a '59 MGA and the PV444 engine noise is about twice as loud. The MGA sounds like a sewing machine. The 444 sounds like a guy in the back room throwing stuff around.

Regarding the electric: Before attaching the jumper wire at the fuse box, I was able to register 6 volts across the hot and ground wires at the dome light. But not enough to light the lamp. I'm wondering if I don't have some parasitic draw in the electrical system. Maybe from ground backwards. I wonder what the risk of an electrical fire might be.

[arcturus]

Have you checked that there is indeed a 6 volt bulb and not a 12V? ooops, just re read your first post.
Don't worry about the noise.Is it a b16? A tappy engine is a happy engine. Can you post a photo of the light without the cover, looking at the inside.
I will take and send a pic' of mine in a day or two when I get my PV out of cover.

[Ron Kwas]

bo90;

In that vehicle's simple elec sys, you should measure only supply voltage on supply wiring, or zero on the low (chassis) side wiring, when load is OFF and no current is flowing...obvious info, but after turning switch ON and allowing current to flow, voltage drops will occur which put the load under less voltage to operate correctly...sluggish Blowers or Wipers, yellow Headlights etc. result.

Remember: Voltage Drops occur only across path resistances when drawing current, so voltages should be measured first with switch OFF, to verify wiring, then with switch ON to check for VDs..

A perfect example of this is your Parking Light symptoms..."parking lights goes off when the headlights are on" ...this is likely a poor chassis connection where both Headlights and Parking Light chassis connections are combined, leading to interaction of circuits. See: http://www.sw-em.com/electical_circuit_interaction.htm

I recommend you spend some time refurbishing electrical connections and preserving them with ACZP...see: http://www.sw-em.com/anti_corrosive_paste.htm

Regarding complaining about the engine sounding like "a guy in the back room throwing stuff around" ...aren't you a bit quick about complaining about your "purchase of opportunity"...who knows when valves were adjusted last time...

Good Hunting!