944 Tail lights don’t work

Repairing my 944 tail lights – Tail light fuse late 944

944 tail light

After my last trip to AMP for track night, I ended up having to drive my race car home due to a tow vehicle failure.  Halfway home, I stopped to eat and noticed the tail lights were not working.  However, I had two very nice tag lights so I elected to make it home anyway.

Last night I decided to dig into why the tail lights were not working. I expected to find a loose wire or failed bulb.  Neither of these was the case.

I then decide to check the fuses and after searching the inside of the fuse box and several internet searches, I could not find a listing for the tail light fuse.   I read through a couple of forums and still no mention of a tail light fuse.

So next I printed out the wiring diagrams.  These are hard for me to follow but even more so in that, the individual bulb functions are not listed on the diagram.  It shows all the bulbs in the tail light housing but not what each one does.

So I pulled the tail lamp assemblies apart and traced the wires from the non-functioning bulbs to the connector and determined the wire color on the harness side fo the connector.  That is when I noticed that a previous owner had redone the wiring so that the left side tail light was jumpered to the right side taillight. I found that odd but continued.

I finally figured out that the tail light bulbs also power the side markers. I don’t have side markers on the race car but I do still have the plugs dangling from the tail light housings.  I remembered seeing a side marker fuse listed when I was researching.

So fuse 40 and 41 are listed for the side markers.  Sure enough, both these fuses were blown. I tried replacing fuse 40 and it would instantly pop indicating a dead short.  Fuse 41 seem loose.

After tracing the wiring diagram again, I figured out why the previous owner had jumpered the two tail lights together.  The left side marker circuit has a dead short.  So he powered the left side off the right side.

I then replaced the fuse for the right side marker circuit and wiggled it around to get it to seat properly.  After some wiggling of connectors in the rear of the car again had tail lights on both sides.

I will later go back and see if I can locate the short in the left side circuit. I expect this is why my left front marker has never worked.

Lexan Rear Hatch for Porsche 944

Lexan Rear Hatch for Porsche 944

944lexan

In order to improve the aerodynamics of our Porsche 944 ChumpCar racer, we decided to add a Lexan hatch. The ChumpCar rules require all glass other than the windshield to be removed. For our first race, we removed the glass and ran just the hatch frame. After looking at the other 944s racing against us we decided to add a Lexan hatch like they had.

We ordered the material from Five Star Race Car bodies on the advice of one of the other teams. This is the same material sold by Porsche specialty shops for about $100 less. The material surprisingly comes rolled up in a small box so shipping costs were reasonable.

Since we already had the glass out of the hatch we were able to start right away. Removing the glass from the hatch frame is challenging and requires a lot of patience. I have seen youtube videos of people breaking theirs out but they still had to deal with all the little pieces in the channels. I used an oscillating tool to cut the bonding material and carefully removed the glass. I had a heat gun for some places but mostly where the bonding material was cut, the glass lifted out.

We began by laying out the screw holes making sure there was no more than ten inches between holes. We paid extra to have the material cut to the size of the original rear glass. We may have been better off buying the oversized version as ours was just a little smaller than we would have liked.

We marked and drilled all the holes in the perimeter of the frame. Then we set the Leaxan in the upper groove and pressed it into place. We then carefully drilled through each hole into the Lexan. I found that if the bit ran too fast, the material would melt rather than drill and would refill the holes when the drill bit was removed. After a few holes I had the technique down. The biggest trouble we had was finding the right place to drill the holes. The best spacing away fort eh edge of the window put us in a ridge on the inside of the frame. This caused some of the holes to be angled which gave us trouble later.

We used a hand brace and a large drill bit to cut the counter sinks. We used the screws provided in the mounting kit from Five Star. The kit seemed a good value as it came with the right screws, locking nuts and a drill bit.

Due to the way the nuts hit the back of the frame, the ridge caused the nuts to not seat right. We ended up using a cutting tool to notch the frame at each of the screw holes so the nuts could sit flat. This also allowed us to use the shorter screws in the kit allowing the hatch to fit better when back on the car. Notching the frame took away some strength but once careful handling allowed us to get the Lexan mounted without it bending. Once the Lexan was in place the rigidity returned.

We added the two required one inch wide aluminum strips over the hatch and bolted them top and bottom. We then put all the rubber trim pieces back on the hatch to cover the holes and retain the look and function of the original spoiler.

The new hatch is very light weight and looks nice. We hope the performance improvement will be worth the cost and two weekends of work required to make the swap.

944 vs the Dragon

Photo by Glenn Holden

Porsche 944 vs the Dragon

We took our newly acquired 1986 Porsche 944 to the Dragon 8 hill climb in Robbinsville, NC. We figured this would make a good shakedown before our first endurance race.

This year Registration and Tech was located on the hill rather than in the town of Robbinsville. So we made the 12 mile trek and unloaded the car at the bottom and drove up and staked out a spot to paddock on the side of the road.

Tech was a breeze since this car already had a log book. Once registration was complete we set up our spot and saved a spot for our friend Dave (aka Captain Chaos) who uses an ambulance body for a tow vehicle. S2000 driver Krafton and Julie were there with lots of snacks as well. We tuned our radio to the worker frequency so we could keep up with what was happening. The ambulance made a great place to hang out and change in and out of our sweaty driver suits.

captain-chaos

We met up with more friends from previous events and went back to town to eat at Lynne’s place. With the event going on in addition to the regular weekend motorcycle traffic, the restaurant was packed. But we had fun catching up and telling car stories as we waited. The food was excellent as usual. I had the dragon tail chicken.

Saturday morning the weather was beautiful. No fog like in years past. Tom took the first run up the hill and ran 144. I followed with a 144 of my own. My best time last year in the Sentra was 147.

dragonarch944

We were feeling pretty good about the car until on one start, I went to shift from 1 to 2 and found only neutral. We spent some time trying to diagnose on the side of the road and finally decided to load up and take it back to the shop hoping to return on Sunday.

We were working to meet up with our mechanic friend who was on his way up to see us race. He offered some suggestions, so we stopped at the Walmart in Murphy to check the linkage more closely.

I set the ramps out on jack stands and was able to back the car out and had sort of a mini lift. This made access to the transaxle much easier. I soon found a set screw had backed out of the shift linkage. I put it back in and we headed back to the hill.

We had missed a few runs and lunch but we each got in two more runs on Saturday. We were both down to 140 being careful with the shifter.

Saturday night we went to the historic Tapaco lodge for dinner. We ate outdoors by the river. The weather was perfect and we enjoyed a variety of foods including wood fired smores pizza for desert.
Tapaco

Sunday morning, I broke into the 139’s on my first run. I also broke the shifter again on the way down. However, this time I knew what to do and had it fixed in time for Tom to make his run group. He was tentative in his shifting and stayed in the 140’s. I will be putting a safety wire on this screw before we endurance race it.

I slowly chipped away at my times during the day. Being careful with the shifter, I started running in third and just holding at the rev limiter in the short straights instead of shifting to forth. This method actually helped my times. By the end of the day I was at 138.1. Tom got 138.5.

time slips

I really enjoyed diving the Porsche. The balanced handling gives me a lot of confidence in the car. I think this will help when driving in traffic on the road course.

Glenn Holden got some great shots of our car: (some of Dave and Krafton as well)

In car video is up on youtube.